Seminar #87 from Online Seminars for Municipal Arborists
July - September 2020
Sections Go directly to the section by clicking on the title below
July - September 2020
Sections Go directly to the section by clicking on the title below
Note: Click on green text in each section for more information and photos.
Note: Click on green text in each section for more information and photos.
Women in Arboriculture
Melissa Duffy
Melissa M. Duffy is an Arboriculture Instructor at Bristol County Agricultural High School in Dighton, MA. With her in this photo (link above) is Dennis Ryan, retired chair of the Arboriculture/Urban Forestry Program at the University of Massachusetts.
Here is her story.
First I need to say thank you to all those who have helped me to become who I am and who opened the doors of opportunity. When I was a child, I had big dreams that many others believed were ridiculous. I realize now that my life has been much better and more rewarding than I ever dreamed it would be. However, there have been many unexpected challenges, disappointments, and crises along the road to my success. I have learned it is true that blessings sometimes come in disguise. As I reflect, I realize that those crazy dreams were a compass to my life’s purpose. It’s strange how things happen.
When I was young, I loved to spend time with my grandparents who watched the Waltons on the television. I wanted to be like the Waltons (living the country life instead of the city). Coincidentally, next door to my grandparents was my friend whose mother was a teacher. When we played together, we would make believe we were teachers and play school with our dolls; passing out school papers, teaching them things and scolding them if they were naughty. I also had a growing love for helping children in need.
Meanwhile, my second grade teacher had us plant pumpkin seeds in a little milk container to grow at home. I was super excited because my grandfather taught me how to grow the pumpkins in his garden. That just intensified my passion to be a Walton, a farmer, a teacher, and someone who could help children who were less fortunate.
As I approached my high school days, I learned about the programs at Bristol Aggie (Bristol County Agricultural High School) in Dighton, Massachusetts. I was super happy to go to an agricultural school with the determination to be a farmer. I loved the animals and farming, but soon learned that it was not realistic to have a farm in a city, and there was no land in my family for a farm. It was then that I became aware of arboriculture and learned that Bristol Aggie was the only high school arboriculture program in the United States. After participating in a few tree climbing classes, my instructor noticed my potential and helped me gain enough confidence to match the determination that got me to where I am today. The teachers support is what I needed at a crucial time in my life as I was learning to make a life for myself. The great plan was to be an arborist, become a teacher, make money, and buy a home with land in the countryside (it happened). Before I graduated, I told one of my instructors “Watch, I will be back in ten years to take your place” and he replied “That is fine. I will be the director by then”.
I wanted to go straight into the industry but it was not the ‘norm’ for women back then, so I was encouraged to pursue the career by attending the Stockbridge School of Agriculture. While at Stockbridge, I majored in Arboriculture and Park Management and earned my Associate of Science degree. Fortunately, I had some fantastic classmates who were arborists and employed me on the weekends. They taught me about tree climbing, removals, bucket truck operation, and landscape construction. As I worked on different crews, it was natural for me to use my teaching skills to help new employees become acclimated to the existing crew and the basics of how the operation was run.
Many people also encouraged me to become a teacher, so, I continued my education and was able to obtain my Bachelor of Science Degree in Urban Forestry/Natural Resources with a minor in Agricultural Education. While pursuing my degree, I was able to student teach and earn my teaching license.
I wanted to continue working in the tree industry so I went to work full time at a tree company in Connecticut. While at this tree company, I worked as a production arborist in multiple facets of commercial tree care. This job enabled me to become a stronger and more resilient person (a skill necessary for a teacher). Along the way I earned my Pesticide License, a Massachusetts Arborist Certification, a Connecticut Arborist License, and an International Society of Arboriculture (ISA) Certification, all while obtaining a teaching license.
As time went on, I realized that if I wanted to be a teacher in CT, I would need a Master of Science degree. So another amazing opportunity came up and I went back to UMass for my MS degree. While there, I worked at the new UMass Urban Forestry Diagnostic Lab with some of the best entomologists and pathologists in the country. They were diagnosing woody plant problems while also collaborating with the extension specialists throughout New England to create the publication of the “1994 New England Management Recommendations for Insects, Diseases and Weeds of Shade Trees and Woody Ornamentals”.
After that great opportunity, I worked at a large tree company as a safety coordinator and Electrical Hazards Awareness Program (EHAP) trainer until I got the call on line 2. “Is this the brat from Bristol Aggie?” I immediately knew who it was. “Are you ready to own up on that promise you made? I am the director now”. Needless to say, I went back to Bristol Aggie and became the Arbor teacher. I was the only applicant that had field experience, appropriate college degrees, professional certifications, a teaching license and a love for the Aggie. Becoming a colleague alongside my original supporters was a definite dream come true.
It has been 25 years of trying to impact the lives of young students. Along the way, I have had the opportunity to meet amazing arboricultural professionals who have become inspirational friends. I also reconnected after many years with a fellow BA graduate arborist at an Arbor Day celebration who is now my husband and soul mate.
With encouragement to climb in the New England Tree Climbing Competition, I won and represented New England at the Inaugural North American Tree Climbing Competition. I now volunteer at regional and international tree climbing competitions. I was also fortunate to be chosen to receive the ‘Golden Ticket’ to attend the North American Training Solutions Intensive Training Program.
Along the way, I have also had the opportunity to join the team of the Women’s’ Tree Climbing Workshop. I have assisted with animal wildlife studies by climbing trees to remove fisher cat kits from their dens to take measurements and study them. A highlight of the project for me was having a photograph of me, holding a fisher, on the cover of the Massachusetts Wildlife Magazine. On several occasions, opportunities have arisen to be a guest speaker at various professional events. It feels weird to have received so much recognition for being a ‘tree chick’.
I am very grateful for so many people, opportunities and successes that have made my life very fulfilling. Words cannot express the gratitude I have for the people that have been instrumental to my success.
I never realized what my mom meant about being her “little pioneer” (I thought she meant a Little House on the Prairie pioneer). When I was young, aspiring and scared, I thought the barrier was just that I personally needed a chance to show that I could do it; not realizing the bigger picture of the whole ‘womanhood’ thing. Thankfully, the doors of opportunity were opened for me as they now are for many other women to excel and make a life for themselves. My hope and goal in life is to help others achieve a sense of accomplishment and to live a fulfilling life.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Municipal Specialist, or BCMA management credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Melissa Duffy
Melissa M. Duffy is an Arboriculture Instructor at Bristol County Agricultural High School in Dighton, MA. With her in this photo (link above) is Dennis Ryan, retired chair of the Arboriculture/Urban Forestry Program at the University of Massachusetts.
Here is her story.
First I need to say thank you to all those who have helped me to become who I am and who opened the doors of opportunity. When I was a child, I had big dreams that many others believed were ridiculous. I realize now that my life has been much better and more rewarding than I ever dreamed it would be. However, there have been many unexpected challenges, disappointments, and crises along the road to my success. I have learned it is true that blessings sometimes come in disguise. As I reflect, I realize that those crazy dreams were a compass to my life’s purpose. It’s strange how things happen.
When I was young, I loved to spend time with my grandparents who watched the Waltons on the television. I wanted to be like the Waltons (living the country life instead of the city). Coincidentally, next door to my grandparents was my friend whose mother was a teacher. When we played together, we would make believe we were teachers and play school with our dolls; passing out school papers, teaching them things and scolding them if they were naughty. I also had a growing love for helping children in need.
Meanwhile, my second grade teacher had us plant pumpkin seeds in a little milk container to grow at home. I was super excited because my grandfather taught me how to grow the pumpkins in his garden. That just intensified my passion to be a Walton, a farmer, a teacher, and someone who could help children who were less fortunate.
As I approached my high school days, I learned about the programs at Bristol Aggie (Bristol County Agricultural High School) in Dighton, Massachusetts. I was super happy to go to an agricultural school with the determination to be a farmer. I loved the animals and farming, but soon learned that it was not realistic to have a farm in a city, and there was no land in my family for a farm. It was then that I became aware of arboriculture and learned that Bristol Aggie was the only high school arboriculture program in the United States. After participating in a few tree climbing classes, my instructor noticed my potential and helped me gain enough confidence to match the determination that got me to where I am today. The teachers support is what I needed at a crucial time in my life as I was learning to make a life for myself. The great plan was to be an arborist, become a teacher, make money, and buy a home with land in the countryside (it happened). Before I graduated, I told one of my instructors “Watch, I will be back in ten years to take your place” and he replied “That is fine. I will be the director by then”.
I wanted to go straight into the industry but it was not the ‘norm’ for women back then, so I was encouraged to pursue the career by attending the Stockbridge School of Agriculture. While at Stockbridge, I majored in Arboriculture and Park Management and earned my Associate of Science degree. Fortunately, I had some fantastic classmates who were arborists and employed me on the weekends. They taught me about tree climbing, removals, bucket truck operation, and landscape construction. As I worked on different crews, it was natural for me to use my teaching skills to help new employees become acclimated to the existing crew and the basics of how the operation was run.
Many people also encouraged me to become a teacher, so, I continued my education and was able to obtain my Bachelor of Science Degree in Urban Forestry/Natural Resources with a minor in Agricultural Education. While pursuing my degree, I was able to student teach and earn my teaching license.
I wanted to continue working in the tree industry so I went to work full time at a tree company in Connecticut. While at this tree company, I worked as a production arborist in multiple facets of commercial tree care. This job enabled me to become a stronger and more resilient person (a skill necessary for a teacher). Along the way I earned my Pesticide License, a Massachusetts Arborist Certification, a Connecticut Arborist License, and an International Society of Arboriculture (ISA) Certification, all while obtaining a teaching license.
As time went on, I realized that if I wanted to be a teacher in CT, I would need a Master of Science degree. So another amazing opportunity came up and I went back to UMass for my MS degree. While there, I worked at the new UMass Urban Forestry Diagnostic Lab with some of the best entomologists and pathologists in the country. They were diagnosing woody plant problems while also collaborating with the extension specialists throughout New England to create the publication of the “1994 New England Management Recommendations for Insects, Diseases and Weeds of Shade Trees and Woody Ornamentals”.
After that great opportunity, I worked at a large tree company as a safety coordinator and Electrical Hazards Awareness Program (EHAP) trainer until I got the call on line 2. “Is this the brat from Bristol Aggie?” I immediately knew who it was. “Are you ready to own up on that promise you made? I am the director now”. Needless to say, I went back to Bristol Aggie and became the Arbor teacher. I was the only applicant that had field experience, appropriate college degrees, professional certifications, a teaching license and a love for the Aggie. Becoming a colleague alongside my original supporters was a definite dream come true.
It has been 25 years of trying to impact the lives of young students. Along the way, I have had the opportunity to meet amazing arboricultural professionals who have become inspirational friends. I also reconnected after many years with a fellow BA graduate arborist at an Arbor Day celebration who is now my husband and soul mate.
With encouragement to climb in the New England Tree Climbing Competition, I won and represented New England at the Inaugural North American Tree Climbing Competition. I now volunteer at regional and international tree climbing competitions. I was also fortunate to be chosen to receive the ‘Golden Ticket’ to attend the North American Training Solutions Intensive Training Program.
Along the way, I have also had the opportunity to join the team of the Women’s’ Tree Climbing Workshop. I have assisted with animal wildlife studies by climbing trees to remove fisher cat kits from their dens to take measurements and study them. A highlight of the project for me was having a photograph of me, holding a fisher, on the cover of the Massachusetts Wildlife Magazine. On several occasions, opportunities have arisen to be a guest speaker at various professional events. It feels weird to have received so much recognition for being a ‘tree chick’.
I am very grateful for so many people, opportunities and successes that have made my life very fulfilling. Words cannot express the gratitude I have for the people that have been instrumental to my success.
I never realized what my mom meant about being her “little pioneer” (I thought she meant a Little House on the Prairie pioneer). When I was young, aspiring and scared, I thought the barrier was just that I personally needed a chance to show that I could do it; not realizing the bigger picture of the whole ‘womanhood’ thing. Thankfully, the doors of opportunity were opened for me as they now are for many other women to excel and make a life for themselves. My hope and goal in life is to help others achieve a sense of accomplishment and to live a fulfilling life.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Municipal Specialist, or BCMA management credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Women in Arboriculture
Asia Dowtin
Asia Dowtin is an Assistant Professor of Urban Forestry in the Department of Forestry at the Michigan State University.
Here is her story.
I grew up in Roosevelt, New York, a small Long Island suburb about 45 minutes outside of New York City. When I left home for college at the State University of New York College at Oneonta, I was eager to begin my studies in meteorology. While I enjoyed learning about the complexities of how weather systems form, and how to predict them in time for the evening news weather forecast, I felt that there was something missing. Like there was something more I wanted to learn – specifically about how precipitation produced by these systems, interacted with the earth’s surface, and the related impacts these interactions would have both on people’s day-to-day lives, and on socio-ecological systems over long time periods.
That prompted a shift in my academic focus, and I became interested in the relationships between climate, water, and society. As a result, I accepted an offer to pursue a master’s degree in Geography at the University of Delaware (UD), where I was able to explore these curiosities. While at UD, I had the amazing opportunity to complete an internship with The Nature Conservancy (TNC) in Delaware. What I believed would simply be a few months of summer work turned into a learning experience with life-altering impacts.
I joined TNC as the Delaware state chapter (and really, the entirety of the organization) was beginning to expand its focus to include urban conservation. I was hired to begin some of the preliminary work on this initiative for TNC Delaware. This included conducting comprehensive literature reviews on urban hydrology and sustainability; meeting with local leaders in urban and regional planning and natural resource management; and synthesizing all the information I had gained from these endeavors into a white paper that TNC Delaware could use to guide forthcoming efforts in urban conservation. Much of these future efforts would include the use of vegetated green infrastructure to mitigate stormwater, and this was of the most interest to me.
The work at TNC, like previous life experiences, shifted my academic focus once again, and I became intently interested in the relationships between urban trees, water quantity, and water quality. This led to the formation of my doctoral research, in which I studied how structural characteristics of the urban forest impact the degree to which water is captured by the canopy, and the degree to which precipitation chemistry is altered due to its interaction with urban trees. I completed that work in 2018, earning my PhD in Geography from UD.
Shortly after, in the summer of 2018, I began my current role as an assistant professor of urban forestry at MSU. In this position, my appointment includes research, extension, and teaching responsibilities. As such, my current research builds on the work I began in Delaware, and I am continuing to study urban forest hydrology in remnant woodlots. I have a phenomenal group of graduate and undergraduate students who are advancing current related work in mid-Michigan, with a strong focus on the influence different tree species exert on hydrologic and nutrient cycling near East Lansing, Michigan.
As my research program continues to grow, so does my awareness of the need to ensure that findings from the research are made accessible and practical for urban forestry practitioners across the state. As such, I am grateful that my extension appointment affords me the opportunity to engage in effective scientific communication, and to work with communities and urban foresters across Michigan to continue to advance their respective urban forestry initiatives.
Additionally, I teach an urban and community forestry course to undergraduate and graduate students at MSU. Providing instruction in this class has assured me that we have a strong group of young professionals who will soon be entering the urban forestry workforce. Over the past two years, I have also engaged in collaborative efforts to prepare students and young professionals for academic and practice-based careers in urban forestry and arboriculture, which has led to an expansion of the research focus of my lab group, and to ongoing efforts in arboricultural training program development.
As the ecological and social patterns that influence our world are changing at unprecedented rates, a steadily increasing amount of people continue to seek balance from the stability that nature – and honestly, our urban forests – tend to provide. I thus look forward to continuing my work of better understanding how our urban forests function, so that they are sustainably managed to meet the social, health, and environmental needs of our current and future generations. I also embrace both current and forthcoming opportunities to contribute to the academic growth and professional development of the urban forestry and arboriculture practitioners who will advance this work in the years to come.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Municipal Specialist, or BCMA management credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Asia Dowtin
Asia Dowtin is an Assistant Professor of Urban Forestry in the Department of Forestry at the Michigan State University.
Here is her story.
I grew up in Roosevelt, New York, a small Long Island suburb about 45 minutes outside of New York City. When I left home for college at the State University of New York College at Oneonta, I was eager to begin my studies in meteorology. While I enjoyed learning about the complexities of how weather systems form, and how to predict them in time for the evening news weather forecast, I felt that there was something missing. Like there was something more I wanted to learn – specifically about how precipitation produced by these systems, interacted with the earth’s surface, and the related impacts these interactions would have both on people’s day-to-day lives, and on socio-ecological systems over long time periods.
That prompted a shift in my academic focus, and I became interested in the relationships between climate, water, and society. As a result, I accepted an offer to pursue a master’s degree in Geography at the University of Delaware (UD), where I was able to explore these curiosities. While at UD, I had the amazing opportunity to complete an internship with The Nature Conservancy (TNC) in Delaware. What I believed would simply be a few months of summer work turned into a learning experience with life-altering impacts.
I joined TNC as the Delaware state chapter (and really, the entirety of the organization) was beginning to expand its focus to include urban conservation. I was hired to begin some of the preliminary work on this initiative for TNC Delaware. This included conducting comprehensive literature reviews on urban hydrology and sustainability; meeting with local leaders in urban and regional planning and natural resource management; and synthesizing all the information I had gained from these endeavors into a white paper that TNC Delaware could use to guide forthcoming efforts in urban conservation. Much of these future efforts would include the use of vegetated green infrastructure to mitigate stormwater, and this was of the most interest to me.
The work at TNC, like previous life experiences, shifted my academic focus once again, and I became intently interested in the relationships between urban trees, water quantity, and water quality. This led to the formation of my doctoral research, in which I studied how structural characteristics of the urban forest impact the degree to which water is captured by the canopy, and the degree to which precipitation chemistry is altered due to its interaction with urban trees. I completed that work in 2018, earning my PhD in Geography from UD.
Shortly after, in the summer of 2018, I began my current role as an assistant professor of urban forestry at MSU. In this position, my appointment includes research, extension, and teaching responsibilities. As such, my current research builds on the work I began in Delaware, and I am continuing to study urban forest hydrology in remnant woodlots. I have a phenomenal group of graduate and undergraduate students who are advancing current related work in mid-Michigan, with a strong focus on the influence different tree species exert on hydrologic and nutrient cycling near East Lansing, Michigan.
As my research program continues to grow, so does my awareness of the need to ensure that findings from the research are made accessible and practical for urban forestry practitioners across the state. As such, I am grateful that my extension appointment affords me the opportunity to engage in effective scientific communication, and to work with communities and urban foresters across Michigan to continue to advance their respective urban forestry initiatives.
Additionally, I teach an urban and community forestry course to undergraduate and graduate students at MSU. Providing instruction in this class has assured me that we have a strong group of young professionals who will soon be entering the urban forestry workforce. Over the past two years, I have also engaged in collaborative efforts to prepare students and young professionals for academic and practice-based careers in urban forestry and arboriculture, which has led to an expansion of the research focus of my lab group, and to ongoing efforts in arboricultural training program development.
As the ecological and social patterns that influence our world are changing at unprecedented rates, a steadily increasing amount of people continue to seek balance from the stability that nature – and honestly, our urban forests – tend to provide. I thus look forward to continuing my work of better understanding how our urban forests function, so that they are sustainably managed to meet the social, health, and environmental needs of our current and future generations. I also embrace both current and forthcoming opportunities to contribute to the academic growth and professional development of the urban forestry and arboriculture practitioners who will advance this work in the years to come.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Municipal Specialist, or BCMA management credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Gothenburg, Sweden
Edited by Len Phillips
Sweden is a global leader in the tourism-sustainability movement and Gothenburg is its second-largest city. Located on Sweden’s scenic west coast, the former industrial port was not always environmentally conscious. Many of the trees in the city were planted a long time ago, when the streets and cityscape looked very different than today. But times have changed and for the past three years, Gothenburg city has been declared the world's most sustainable destination.
The city changed in the mid-1980s, when political and business leaders vowed to transform the gritty 17th-Century city into a beacon of urban sustainability. That effort was partially the result of widespread community engagement, and it seems to have worked. Today, Gothenburg has a glass and cast-iron greenhouse with towering palms and exotic plants. It has blue-and-white electric trams scooting along the streets and passing people riding bikes. It has roasted coffee, craft beer, some of world’s best seafood and a dozen varieties of vegan “milk”. It has Dutch-built canals, lush urban parks and cobblestone streets, where you can walk from your hotel to shopping, restaurants and nightlife. It has a ferry that takes you across the Götaälv River to a free sauna and public pool, where the water is cleaned entirely without chlorine and the changing rooms are made of recycled bottles.
The Garden Society of Gothenburg is an oasis of greenery in the heart of the city. The Botanical Garden is one of the largest and best botanical gardens in Europe. Just across from there you’ll find Slottsskogen, a green meeting place and the main park of Gothenburg.
Trees can be a major feature of many cultural-historical environments and in Gothenburg, trees give the city its character and contribute to a healthier urban environment. Today there are about 31,000 trees thriving in the city's parks and along the streets. There are also many more trees on other municipal and private lands. In addition, the City of Gothenburg owns over 27,000 acres (11,000 hectares) of forested lands.
The parks are a popular choice among connoisseurs with green fingers, as well as anyone just wanting to go for a walk in the open air. The compact city center makes it easy to walk to the Botanical Garden's flower beds or drop by the Garden Society.
Trees are in competition for space below and above ground. Underground, the tree's root system competes with water and sewer lines as well as electricity and broadband cables, and district heating and cooling pipes. Above ground, the tree branches compete with nearby properties, poles for lighting and contact lines for trams. Despite all the potential problems the trees manage to survive.
On a hotel rooftop is an organic vegetable garden planted by urban farmers as part of an emerging “hyper-local” produce movement. Visitors to the city can join urban safaris to learn more about local food production on a tour of the city’s several urban farms and gardens, such as a commercial vegetable farm atop a pier in the industrial area of Frihamnen.
One of Gothenburg’s advantages is its intimacy and accessibility. To explore the compact city, rent a bike from Styr & Stall, a bike-sharing system with 72 stations, or try an electric scooter (and get praised via the app for choosing this “carbon-neutral” ride). Also consider one of the city’s 260 electric trams, many of them named after famous Gothenburg citizens, or enjoy the sights from a quiet, zero-emission electric bus. Currently, 65% of Gothenburg’s public transportation hums on renewable energy, with the goal of making it fully electric is by 2030.
Gothenburg would not be truly green, of course, without its proximity to nature. Surrounded by thick forests of linden and beech, the city offers a hefty 3,000 sq. ft. (275 sq. m.) of green space per citizen. The Botanical Garden and Slottsskogen, the city’s most beautiful parks, are wonderful places to explore. At the latter, you will find tranquil meadows and wooded paths, Sweden’s only free zoo and the Gothenburg Natural History Museum claims to have the world’s only full-size taxidermy blue whale.
More recently, the city has created Gotaleden, a walking trail that starts in Gothenburg and links up with various train stations along the 44 mi (71km) route. The end point is the small town of Alingsas, often described as “the capital of Swedish fika” (a beloved Swedish ritual where people pause during the day to gather with friends over coffee and cake) as it has the most cafes per capita in the country.
Gothenburg’s once-grungy harbor has been cleaned up to accommodate the city's growing population. Change is evident everywhere. The skyline now contains glass and steel structures above the waterfront, and construction cranes pierce the sky.
Next year will be the 400th anniversary of Gothenburg and the city has been busy preparing by running workshops with young people hosting sustainable urban design conferences and consulting residents on sustainability projects that enhance life for locals.
One of the most exciting projects is unfolding in a neighborhood near the outdoor pool and sauna. The goal is to make the area a green and a dynamic part of the inner city. Local residents have been busy designing new activities and projects here, including a “rain” playground for children built to accommodate the region’s frequent downpours. This is a new approach to urban development, with people allowed to gradually take over the area and make it their own.
In its work, the Park and Nature Administration (tree and park maintenance department) strives to create good conditions for the city's trees. The Administration is actively working on new installations and replanting trees in parks and avenues to ensure that Gothenburg remains a green city in the future. Every year the Administration plants about 1,200 new trees in the city. The Administration is also working to try to minimize future space conflicts for the trees, above and below ground, through advanced planning in replanting projects.
Gothenburg is planning for challenges to its sustainability goals, as well. You have only to peruse the city’s blueprint for the future which includes efforts to tackle the rising sea levels predicted in the next decade and efforts to prevent the river from flooding. This is a city of residents that clearly see their future and the future of their world.
Sources
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Municipal Specialist, or BCMA management credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Edited by Len Phillips
Sweden is a global leader in the tourism-sustainability movement and Gothenburg is its second-largest city. Located on Sweden’s scenic west coast, the former industrial port was not always environmentally conscious. Many of the trees in the city were planted a long time ago, when the streets and cityscape looked very different than today. But times have changed and for the past three years, Gothenburg city has been declared the world's most sustainable destination.
The city changed in the mid-1980s, when political and business leaders vowed to transform the gritty 17th-Century city into a beacon of urban sustainability. That effort was partially the result of widespread community engagement, and it seems to have worked. Today, Gothenburg has a glass and cast-iron greenhouse with towering palms and exotic plants. It has blue-and-white electric trams scooting along the streets and passing people riding bikes. It has roasted coffee, craft beer, some of world’s best seafood and a dozen varieties of vegan “milk”. It has Dutch-built canals, lush urban parks and cobblestone streets, where you can walk from your hotel to shopping, restaurants and nightlife. It has a ferry that takes you across the Götaälv River to a free sauna and public pool, where the water is cleaned entirely without chlorine and the changing rooms are made of recycled bottles.
The Garden Society of Gothenburg is an oasis of greenery in the heart of the city. The Botanical Garden is one of the largest and best botanical gardens in Europe. Just across from there you’ll find Slottsskogen, a green meeting place and the main park of Gothenburg.
Trees can be a major feature of many cultural-historical environments and in Gothenburg, trees give the city its character and contribute to a healthier urban environment. Today there are about 31,000 trees thriving in the city's parks and along the streets. There are also many more trees on other municipal and private lands. In addition, the City of Gothenburg owns over 27,000 acres (11,000 hectares) of forested lands.
The parks are a popular choice among connoisseurs with green fingers, as well as anyone just wanting to go for a walk in the open air. The compact city center makes it easy to walk to the Botanical Garden's flower beds or drop by the Garden Society.
Trees are in competition for space below and above ground. Underground, the tree's root system competes with water and sewer lines as well as electricity and broadband cables, and district heating and cooling pipes. Above ground, the tree branches compete with nearby properties, poles for lighting and contact lines for trams. Despite all the potential problems the trees manage to survive.
On a hotel rooftop is an organic vegetable garden planted by urban farmers as part of an emerging “hyper-local” produce movement. Visitors to the city can join urban safaris to learn more about local food production on a tour of the city’s several urban farms and gardens, such as a commercial vegetable farm atop a pier in the industrial area of Frihamnen.
One of Gothenburg’s advantages is its intimacy and accessibility. To explore the compact city, rent a bike from Styr & Stall, a bike-sharing system with 72 stations, or try an electric scooter (and get praised via the app for choosing this “carbon-neutral” ride). Also consider one of the city’s 260 electric trams, many of them named after famous Gothenburg citizens, or enjoy the sights from a quiet, zero-emission electric bus. Currently, 65% of Gothenburg’s public transportation hums on renewable energy, with the goal of making it fully electric is by 2030.
Gothenburg would not be truly green, of course, without its proximity to nature. Surrounded by thick forests of linden and beech, the city offers a hefty 3,000 sq. ft. (275 sq. m.) of green space per citizen. The Botanical Garden and Slottsskogen, the city’s most beautiful parks, are wonderful places to explore. At the latter, you will find tranquil meadows and wooded paths, Sweden’s only free zoo and the Gothenburg Natural History Museum claims to have the world’s only full-size taxidermy blue whale.
More recently, the city has created Gotaleden, a walking trail that starts in Gothenburg and links up with various train stations along the 44 mi (71km) route. The end point is the small town of Alingsas, often described as “the capital of Swedish fika” (a beloved Swedish ritual where people pause during the day to gather with friends over coffee and cake) as it has the most cafes per capita in the country.
Gothenburg’s once-grungy harbor has been cleaned up to accommodate the city's growing population. Change is evident everywhere. The skyline now contains glass and steel structures above the waterfront, and construction cranes pierce the sky.
Next year will be the 400th anniversary of Gothenburg and the city has been busy preparing by running workshops with young people hosting sustainable urban design conferences and consulting residents on sustainability projects that enhance life for locals.
One of the most exciting projects is unfolding in a neighborhood near the outdoor pool and sauna. The goal is to make the area a green and a dynamic part of the inner city. Local residents have been busy designing new activities and projects here, including a “rain” playground for children built to accommodate the region’s frequent downpours. This is a new approach to urban development, with people allowed to gradually take over the area and make it their own.
In its work, the Park and Nature Administration (tree and park maintenance department) strives to create good conditions for the city's trees. The Administration is actively working on new installations and replanting trees in parks and avenues to ensure that Gothenburg remains a green city in the future. Every year the Administration plants about 1,200 new trees in the city. The Administration is also working to try to minimize future space conflicts for the trees, above and below ground, through advanced planning in replanting projects.
Gothenburg is planning for challenges to its sustainability goals, as well. You have only to peruse the city’s blueprint for the future which includes efforts to tackle the rising sea levels predicted in the next decade and efforts to prevent the river from flooding. This is a city of residents that clearly see their future and the future of their world.
Sources
- Gable, Mona, “Is Gothenburg Europe's Greenest City”, BBC, February 24, 2020.
- Gothenburg Park and Nature Administration communications February 27, 2020.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Municipal Specialist, or BCMA management credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Tree of the Seminar
by Len Phillips
Maackia amurensis, commonly called Amur maackia and Asian Yellowwood, is native to China, Japan, Korea, and far-eastern Russia. It is in the Fabaceae family, commonly known as the legume, pea, or bean family.
Amur maackia has an impressive adaptability to a wide range of soil conditions such as along stream banks and soils that are dry, cold, heavy, sandy, and are sometimes flooded. It is tolerant of both acidic and alkaline soils, especially if the soil is otherwise fertile. This tree also does well in full sun. It should also be grown in USDA Zones 3 to 7 and AHS Heat Zone 7 to 4.
Maackia amurensis has been observed growing to 60 feet (20 m) tall in the wild but in cultivation the tree is very slow-growing and reaches about 20 to 30 feet (6 – 10 m) tall in 40 to 50 years. It is a deciduous tree with a small, rounded form and arching branches.
The leaves of Amur maackia emerge in early spring with a silver-green appearance due to the fuzzy underside of the odd pinnately and compound leaves that contain 7-13 elliptical leaflets, with a terminal leaflet at the end. These young, silvery, downy leaves are quite noticeable and ornamental. The leaflets tops turn dark green in summer while the undersides are light green to silver caused by tiny silver hairs. There is no autumn color. The leaves typically drop off the tree after the first frost, while they are still green.
In late spring, Amur maackia's emerging flower buds have two scales covered with tiny hairs which appear silvery and showy like flowers with frost on them and are ¼ inch (0.6 cm) tall and dark brown. The flowers bloom in upright, narrow, spike-like clusters, 4 – 6 inches (10 – 15 cm) tall. The flowers are pea shaped and smell like freshly cut grass. They are perfect, creamy-white and tinged with very pale, dark-blue petals. The flowers are a half-inch (1.3 cm) long and like most trees in the pea family, heavy blooming does not occur every year. They are not particularly showy, but they come into bloom at a time when few other trees are in flower. The fruits are flat and green changing to brown seed pods, two-to-three inches (5 – 7 cm) long and containing 3 to 5 seeds similar to what is observed on a redbud. Propagation is by seed and softwood cuttings.
Maackia amurensis was discovered by Richard Karlovich Maack (1825-1886), a 19th century Siberian naturalist and explorer, who found this tree growing in the region of the Amur River, which serves as the border between Siberia and China. Maackia amurensis was introduced into cultivation in 1864. There are 12 species of Maackia distributed throughout Eastern Asia with six species endemic to China. Like other plants in the pea family, Amur maackia can fix atmospheric nitrogen through a symbiosis with root bacteria called rhizobia. This species is tolerant of drought and both acidic and alkaline soils. It also tolerates periodically wet soils, but this tree is not well suited for poorly drained soil or prolonged standing water.
Amur maackia has a short main trunk that bifurcates into multiple main branches 2 to 3 feet (0.6 to 1 m) from the ground. The contribution of ornamental bark only increases with age and is most conspicuous in the dormant season. Twigs are stout and gray-brown to black. The leaf drop reveals the luminescent coppery-bronze tones of the smooth shiny bark that exfoliates with age into loose curls, peels, and flakes. The bark is another distinctive feature of this tree, although this characteristic can be quite variable. The primary trunk initially gets interesting “diamond” patterns and the glossiness of both trunk and larger branches are conspicuous throughout the season.
Maackia amurensis is not attacked by any significant pests or diseases and foliage often looks great throughout the growing season. It is quite adaptable to different pH levels and is easily transplanted. While preferring full sun, Amur maackia will also tolerate partial shade.
Propagated by seed or softwood cuttings, this tree is not quick to establish, but once settled in the landscape, it grows reliably. The species is becoming more popular as a street tree due to its ability to tolerate dry, poor soils and harsh cold. The slow growth rate coupled with medium height at maturity are factors that may be favorable in select urban situations. Excessive exposure to salt should also be avoided, although specimens used along streets seem to accept average salting effects in the winter with little impact or difficulty.
The dark colored wood of Amur maackia is quite hard and rot resistant and has long been used in fencing material, tool handles and utensils in its native region and beyond. It also does well for the lining of a street, with or without sidewalks, and wide medians provided it is pruned to provide clearance. It has also been seen thriving in parking lot islands and areas of poor soil quality.
The list of extremely hardy, “tough-as-nails” trees with few problems and wide adaptability is quite short. Amur maackia should be on this short list as the combination of toughness and beauty of this tree, coupled with exciting potential for use in our urban areas, makes this a selection to know and grow.
Sources
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Municipal Specialist, Utility Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA science credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
by Len Phillips
Maackia amurensis, commonly called Amur maackia and Asian Yellowwood, is native to China, Japan, Korea, and far-eastern Russia. It is in the Fabaceae family, commonly known as the legume, pea, or bean family.
Amur maackia has an impressive adaptability to a wide range of soil conditions such as along stream banks and soils that are dry, cold, heavy, sandy, and are sometimes flooded. It is tolerant of both acidic and alkaline soils, especially if the soil is otherwise fertile. This tree also does well in full sun. It should also be grown in USDA Zones 3 to 7 and AHS Heat Zone 7 to 4.
Maackia amurensis has been observed growing to 60 feet (20 m) tall in the wild but in cultivation the tree is very slow-growing and reaches about 20 to 30 feet (6 – 10 m) tall in 40 to 50 years. It is a deciduous tree with a small, rounded form and arching branches.
The leaves of Amur maackia emerge in early spring with a silver-green appearance due to the fuzzy underside of the odd pinnately and compound leaves that contain 7-13 elliptical leaflets, with a terminal leaflet at the end. These young, silvery, downy leaves are quite noticeable and ornamental. The leaflets tops turn dark green in summer while the undersides are light green to silver caused by tiny silver hairs. There is no autumn color. The leaves typically drop off the tree after the first frost, while they are still green.
In late spring, Amur maackia's emerging flower buds have two scales covered with tiny hairs which appear silvery and showy like flowers with frost on them and are ¼ inch (0.6 cm) tall and dark brown. The flowers bloom in upright, narrow, spike-like clusters, 4 – 6 inches (10 – 15 cm) tall. The flowers are pea shaped and smell like freshly cut grass. They are perfect, creamy-white and tinged with very pale, dark-blue petals. The flowers are a half-inch (1.3 cm) long and like most trees in the pea family, heavy blooming does not occur every year. They are not particularly showy, but they come into bloom at a time when few other trees are in flower. The fruits are flat and green changing to brown seed pods, two-to-three inches (5 – 7 cm) long and containing 3 to 5 seeds similar to what is observed on a redbud. Propagation is by seed and softwood cuttings.
Maackia amurensis was discovered by Richard Karlovich Maack (1825-1886), a 19th century Siberian naturalist and explorer, who found this tree growing in the region of the Amur River, which serves as the border between Siberia and China. Maackia amurensis was introduced into cultivation in 1864. There are 12 species of Maackia distributed throughout Eastern Asia with six species endemic to China. Like other plants in the pea family, Amur maackia can fix atmospheric nitrogen through a symbiosis with root bacteria called rhizobia. This species is tolerant of drought and both acidic and alkaline soils. It also tolerates periodically wet soils, but this tree is not well suited for poorly drained soil or prolonged standing water.
Amur maackia has a short main trunk that bifurcates into multiple main branches 2 to 3 feet (0.6 to 1 m) from the ground. The contribution of ornamental bark only increases with age and is most conspicuous in the dormant season. Twigs are stout and gray-brown to black. The leaf drop reveals the luminescent coppery-bronze tones of the smooth shiny bark that exfoliates with age into loose curls, peels, and flakes. The bark is another distinctive feature of this tree, although this characteristic can be quite variable. The primary trunk initially gets interesting “diamond” patterns and the glossiness of both trunk and larger branches are conspicuous throughout the season.
Maackia amurensis is not attacked by any significant pests or diseases and foliage often looks great throughout the growing season. It is quite adaptable to different pH levels and is easily transplanted. While preferring full sun, Amur maackia will also tolerate partial shade.
Propagated by seed or softwood cuttings, this tree is not quick to establish, but once settled in the landscape, it grows reliably. The species is becoming more popular as a street tree due to its ability to tolerate dry, poor soils and harsh cold. The slow growth rate coupled with medium height at maturity are factors that may be favorable in select urban situations. Excessive exposure to salt should also be avoided, although specimens used along streets seem to accept average salting effects in the winter with little impact or difficulty.
The dark colored wood of Amur maackia is quite hard and rot resistant and has long been used in fencing material, tool handles and utensils in its native region and beyond. It also does well for the lining of a street, with or without sidewalks, and wide medians provided it is pruned to provide clearance. It has also been seen thriving in parking lot islands and areas of poor soil quality.
The list of extremely hardy, “tough-as-nails” trees with few problems and wide adaptability is quite short. Amur maackia should be on this short list as the combination of toughness and beauty of this tree, coupled with exciting potential for use in our urban areas, makes this a selection to know and grow.
Sources
- Dirr, Michael A. and Keith S. Warren, “The Tree Book”, Timber Press, 2019.
- Dwyer, Mark, Maackia amurensis, Nursery Management, January 2020
- J. Frank Schmidt & Son Nursery photo, “Amur Maackia”, 2018 http://www.jfschmidt.com/pdfs/amurmaackia.pdf
- Learn 2 Grow, Maackia amurensis, Plant Search, 2017.
- Missouri Botanical Garden, Maackia amurensis, 2017
- Wikipedia,July 7, 2014.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Municipal Specialist, Utility Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA science credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Trees Reaction to Pests
By Len Phillips
When insects invade a tree, how does the tree survive? Especially trees in a forest where there are no arborists available to apply an insecticide or provide other care. But, according to researchers and recent studies, trees do survive and the way they survive is very similar to the way people survive when we get sick.
For example, forest trees are part of a community of trees. Researchers have found that their roots touch each other's roots and through the roots, the trees can transfer information to each other. Forest trees are extremely dependent on each other for their survival. Trees have developed positive communication and cooperation among themselves. People on the other hand, can communicate verbally or by the written word. In the past century, people have also developed electronic ways to communicate.
Forest trees have memories. For example, when attacked by a pest, trees know what chemicals they released the last time this pest attacked and what they had to do to eliminate the problem. For example, oak trees will produce toxic tannins in their bark and leaves to either kill the pest or make the leaves taste bitter. Willows produce salicylic acid which works the same way. The tree will release a specific compound to kill or discourage the specific pest based on their past experience and the experience of neighboring trees. However, it will take hours for the compounds to reach the site of the attack. People also have memories and when they get sick they know what medicine will provide comfort and perhaps cure the problem within a day or two.
When trees in the forest get sick from pests, they depend on their neighbors for support. During this time, trees often share essential water and nutrients that can help aid in recovery and allow for normal growth to resume. When people get sick they go to a doctor for treatment that usually requires rest and medicines.
When trees are attacked by a pest, they can produce pheromones that encourage predators of the pest to visit the tree and kill the pest. For example, if the pest is a caterpillar eating tree leaves, the predator may lay its eggs inside the caterpillar. Soon the eggs will hatch and the baby predator eats the caterpillar from the inside out.
Trees experience pain when an animal or insect is eating their leaves. The tree sends out an electrical impulse throughout the whole tree about the pest. The tree also sends this message to its neighbors via the underground fungal and root connections. People also feel pain from a cut or bruise when they have been injured and they call their doctor or go to a hospital to get help for their injury.
A tree will heal by compartmentalization. This will isolate the wound from the healthy parts of the tree and will eventually close over the wound with new wood. People will visit a doctor for advice and perhaps a medicine for serious wounds. For minor wounds people will usually just wait until the body forms a scab over a wound on their skin, allowing the body to heal itself under the scab.
There are times when a pest arrives that the forest tree is not familiar with. When this happens, the pest may win the battle. The Emerald Ash Borer is a prime example. Only the Manchurian Ash (Fraxinus mandschurica) which co-existed with the EAB in its native land, can survive the borer's attack and this ash can live for many years with the borer. However, the EAB is killing thousands of ash trees around the globe, except in Manchuria. (Manchurian Ash and its cultivars and hybrids are quickly being bred to replace the white and green ash that have become a favorite food for the EAB.) People also have many diseases for which we have no cure. The COVID-19 virus is an example where the virus spread quickly all around the globe. However, in this case China, where the virus was first discovered, has not been cured there or anywhere else (at the time of this writing). Many other diseases are studied for years in search for a cure.
City trees are usually isolated from each other, especially street trees where there is very little, if any root or fungi communication among other trees. This is why pests such as the Asian longhorned beetle (ALB) and elm bark beetle have progressed so rapidly through our city trees. (Fortunately for the city trees, pesticides are being developed which will eliminate the beetle that has caused death to so many trees in the city.)
Parent trees recognize their offspring by sending them more fungal mycelium and carbon and reducing their own root size to make soil available for their offspring seedlings. The mycelium web connects parent trees with offspring trees, which allows the parent tree to feed the seedlings. A single parent tree can provide nourishment for hundreds of seedlings in the under-story of the parent branches. In addition, scientists realized that in a forest, trees of the same species are all functioning at the same rate of photosynthesis. This is despite the fact that the trees may be growing in different soils, they may be of different sizes and ages, they may have different access to ground water levels, and sunlight amounts may be different. The reason for this photosynthetic equalization is because the trees are all sharing the water and nutrients gathered through their collective root systems.
Source
Wohlleben, Peter, The Hidden Life of Trees, Greystone Books, 2015.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Municipal Specialist, Utility Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA science credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
By Len Phillips
When insects invade a tree, how does the tree survive? Especially trees in a forest where there are no arborists available to apply an insecticide or provide other care. But, according to researchers and recent studies, trees do survive and the way they survive is very similar to the way people survive when we get sick.
For example, forest trees are part of a community of trees. Researchers have found that their roots touch each other's roots and through the roots, the trees can transfer information to each other. Forest trees are extremely dependent on each other for their survival. Trees have developed positive communication and cooperation among themselves. People on the other hand, can communicate verbally or by the written word. In the past century, people have also developed electronic ways to communicate.
Forest trees have memories. For example, when attacked by a pest, trees know what chemicals they released the last time this pest attacked and what they had to do to eliminate the problem. For example, oak trees will produce toxic tannins in their bark and leaves to either kill the pest or make the leaves taste bitter. Willows produce salicylic acid which works the same way. The tree will release a specific compound to kill or discourage the specific pest based on their past experience and the experience of neighboring trees. However, it will take hours for the compounds to reach the site of the attack. People also have memories and when they get sick they know what medicine will provide comfort and perhaps cure the problem within a day or two.
When trees in the forest get sick from pests, they depend on their neighbors for support. During this time, trees often share essential water and nutrients that can help aid in recovery and allow for normal growth to resume. When people get sick they go to a doctor for treatment that usually requires rest and medicines.
When trees are attacked by a pest, they can produce pheromones that encourage predators of the pest to visit the tree and kill the pest. For example, if the pest is a caterpillar eating tree leaves, the predator may lay its eggs inside the caterpillar. Soon the eggs will hatch and the baby predator eats the caterpillar from the inside out.
Trees experience pain when an animal or insect is eating their leaves. The tree sends out an electrical impulse throughout the whole tree about the pest. The tree also sends this message to its neighbors via the underground fungal and root connections. People also feel pain from a cut or bruise when they have been injured and they call their doctor or go to a hospital to get help for their injury.
A tree will heal by compartmentalization. This will isolate the wound from the healthy parts of the tree and will eventually close over the wound with new wood. People will visit a doctor for advice and perhaps a medicine for serious wounds. For minor wounds people will usually just wait until the body forms a scab over a wound on their skin, allowing the body to heal itself under the scab.
There are times when a pest arrives that the forest tree is not familiar with. When this happens, the pest may win the battle. The Emerald Ash Borer is a prime example. Only the Manchurian Ash (Fraxinus mandschurica) which co-existed with the EAB in its native land, can survive the borer's attack and this ash can live for many years with the borer. However, the EAB is killing thousands of ash trees around the globe, except in Manchuria. (Manchurian Ash and its cultivars and hybrids are quickly being bred to replace the white and green ash that have become a favorite food for the EAB.) People also have many diseases for which we have no cure. The COVID-19 virus is an example where the virus spread quickly all around the globe. However, in this case China, where the virus was first discovered, has not been cured there or anywhere else (at the time of this writing). Many other diseases are studied for years in search for a cure.
City trees are usually isolated from each other, especially street trees where there is very little, if any root or fungi communication among other trees. This is why pests such as the Asian longhorned beetle (ALB) and elm bark beetle have progressed so rapidly through our city trees. (Fortunately for the city trees, pesticides are being developed which will eliminate the beetle that has caused death to so many trees in the city.)
Parent trees recognize their offspring by sending them more fungal mycelium and carbon and reducing their own root size to make soil available for their offspring seedlings. The mycelium web connects parent trees with offspring trees, which allows the parent tree to feed the seedlings. A single parent tree can provide nourishment for hundreds of seedlings in the under-story of the parent branches. In addition, scientists realized that in a forest, trees of the same species are all functioning at the same rate of photosynthesis. This is despite the fact that the trees may be growing in different soils, they may be of different sizes and ages, they may have different access to ground water levels, and sunlight amounts may be different. The reason for this photosynthetic equalization is because the trees are all sharing the water and nutrients gathered through their collective root systems.
Source
Wohlleben, Peter, The Hidden Life of Trees, Greystone Books, 2015.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Municipal Specialist, Utility Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA science credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Washing Roots Before Planting
Edited by Len Phillips
Eighty percent of the problems related to newly planted trees can be traced to root defects, poor root preparation, and poor installation practices. These factors result in circling and girdling roots, root decline, infestations by secondary pests and diseases, and early tree failure. Trunk flare depth is also a problem that is not discovered until the tree has been dug and planted in a new location that often results in an early death of the tree.
Field applications over the past two decades have demonstrated that root washing balled and burlapped (B&B) and containerized trees leads to substantial increases in tree establishment and survival. The process basically changes container and B&B stock to bare root stock. The washing will expose the entire root system and will reveal the trunk flare and graft union. It allows for remediation of poorly oriented and damaged roots, and it eliminates any disparity of texture between the soils of the root ball and the planting site.
Investing the extra time to prepare and install trees properly will pay future dividends of reduced maintenance and a longer life for the tree. Furthermore, washing the roots saves labor during installation because the holes are shallower, less heavy equipment is required, and there are fewer back injuries.
On the other hand, with vigorous washing there is the disadvantage of removing the desirable rhizosphere organisms and the poor recovery due to phenological growth changes in certain species that dislike bare root planting.
The Process
In order to achieve success with the root washing process, there are 10 recommended steps to follow.
2. Place the tree in a large container where the soil can easily be washed off or removed with fingers. Use fingers or small garden hand tools to remove or break up the soil ball or container media. Soil that is packed around the root must be washed off with a hose or swishing the tree up and down in the water of the container. Soaking also allows the soil to slough off gently. The duration of soaking depends on the amount of clay in the root ball and the soil compaction level.
3. Look for root defects and prune any that need removal.
4. Dig the planting hole to be only as deep as the root system and at least three times as wide. The hole planting dimensions will vary depending on the size of the root system, after the soil has been removed. The hole should resemble a shallow saucer.
5. Form a soil mound in the center of the hole to support the root crown of the tree and arrange the roots radially. If the tree has thin bark such as a beech or birch that might sustain sunburn, rotate the tree so the largest branches are facing southwest. This will orient the tree to the same direction as it was in the nursery.
6. Backfill the hole with the soil just removed, while adding water from the bucket. Continue this process in lifts. Do not use any type of soil amendment unless the soil test shows deficiencies.
7. The water used for planting should be from the container used to wash the soil off the roots because it will contain the nutrients and microbes that assisted the tree's growth at the nursery. Water will settle the soil and the tree roots will hold the tree upright. If soil tests indicate a nutrient deficiency, add the appropriate fertilizer at this time. Do not add the fertilizer on the bare roots, because it will burn the roots. Do not step on the roots or in the root zone, not even to pack the roots down. This causes compaction to the soil.
8. Once the soil is added to level with the root flare, mulch the entire planting circle. The depth will vary with the mulch texture. Finer particle mulch should be 2 inches (5 cm) thick or less, while coarse mulch should be 4 inches (10 cm) thick or less. The mulch should start at least 3 inches (7.5 cm) from the trunk of the tree.
9. The decision to stabilize the roots should be made on the basis of the root system volume. If necessary, for windy sites or locations where vandalism may be a problem, the tree roots should be stabilized to the bottom of the planting pit.
10. Water the tree for the next three years adjusting the location of the water according to the annual root growth. The amount of water will vary according to the soil type and rainfall.
Limited Root Wash
Sometimes it may be easier to modify the above steps if the tree can have the soil removed right in the planting hole. In this case the tree is set near the planting site. The wire basket and twine is removed from the top of the root ball and the trunk flare is located using fingers or water from a garden hose. The hole is dug as deep as the root system between the trunk flare and the bottom of the root ball and three times the width. Place the tree in the hole and remove all the remaining wire, burlap, container, and soil with garden hand tools and water. Backfill and continue planting as mentioned above. Root stabilizing and long-term watering are the same as above.
Sources
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Municipal Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA practice credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Edited by Len Phillips
Eighty percent of the problems related to newly planted trees can be traced to root defects, poor root preparation, and poor installation practices. These factors result in circling and girdling roots, root decline, infestations by secondary pests and diseases, and early tree failure. Trunk flare depth is also a problem that is not discovered until the tree has been dug and planted in a new location that often results in an early death of the tree.
Field applications over the past two decades have demonstrated that root washing balled and burlapped (B&B) and containerized trees leads to substantial increases in tree establishment and survival. The process basically changes container and B&B stock to bare root stock. The washing will expose the entire root system and will reveal the trunk flare and graft union. It allows for remediation of poorly oriented and damaged roots, and it eliminates any disparity of texture between the soils of the root ball and the planting site.
Investing the extra time to prepare and install trees properly will pay future dividends of reduced maintenance and a longer life for the tree. Furthermore, washing the roots saves labor during installation because the holes are shallower, less heavy equipment is required, and there are fewer back injuries.
On the other hand, with vigorous washing there is the disadvantage of removing the desirable rhizosphere organisms and the poor recovery due to phenological growth changes in certain species that dislike bare root planting.
The Process
In order to achieve success with the root washing process, there are 10 recommended steps to follow.
- Remove the entire wire basket, twine and burlap, or the container from the root ball. Do this work in a location where the soil can remain for the replanting or where it can easily be transported to another site.
2. Place the tree in a large container where the soil can easily be washed off or removed with fingers. Use fingers or small garden hand tools to remove or break up the soil ball or container media. Soil that is packed around the root must be washed off with a hose or swishing the tree up and down in the water of the container. Soaking also allows the soil to slough off gently. The duration of soaking depends on the amount of clay in the root ball and the soil compaction level.
3. Look for root defects and prune any that need removal.
4. Dig the planting hole to be only as deep as the root system and at least three times as wide. The hole planting dimensions will vary depending on the size of the root system, after the soil has been removed. The hole should resemble a shallow saucer.
5. Form a soil mound in the center of the hole to support the root crown of the tree and arrange the roots radially. If the tree has thin bark such as a beech or birch that might sustain sunburn, rotate the tree so the largest branches are facing southwest. This will orient the tree to the same direction as it was in the nursery.
6. Backfill the hole with the soil just removed, while adding water from the bucket. Continue this process in lifts. Do not use any type of soil amendment unless the soil test shows deficiencies.
7. The water used for planting should be from the container used to wash the soil off the roots because it will contain the nutrients and microbes that assisted the tree's growth at the nursery. Water will settle the soil and the tree roots will hold the tree upright. If soil tests indicate a nutrient deficiency, add the appropriate fertilizer at this time. Do not add the fertilizer on the bare roots, because it will burn the roots. Do not step on the roots or in the root zone, not even to pack the roots down. This causes compaction to the soil.
8. Once the soil is added to level with the root flare, mulch the entire planting circle. The depth will vary with the mulch texture. Finer particle mulch should be 2 inches (5 cm) thick or less, while coarse mulch should be 4 inches (10 cm) thick or less. The mulch should start at least 3 inches (7.5 cm) from the trunk of the tree.
9. The decision to stabilize the roots should be made on the basis of the root system volume. If necessary, for windy sites or locations where vandalism may be a problem, the tree roots should be stabilized to the bottom of the planting pit.
10. Water the tree for the next three years adjusting the location of the water according to the annual root growth. The amount of water will vary according to the soil type and rainfall.
Limited Root Wash
Sometimes it may be easier to modify the above steps if the tree can have the soil removed right in the planting hole. In this case the tree is set near the planting site. The wire basket and twine is removed from the top of the root ball and the trunk flare is located using fingers or water from a garden hose. The hole is dug as deep as the root system between the trunk flare and the bottom of the root ball and three times the width. Place the tree in the hole and remove all the remaining wire, burlap, container, and soil with garden hand tools and water. Backfill and continue planting as mentioned above. Root stabilizing and long-term watering are the same as above.
Sources
- Appleton, Bonnie and Jim Flott, “Back to Basics”, Nursery Management & Production, May 2009.
- Community Forestry Consultants, Inc., “Root Washing Method”, lecture at New England Grows, February 7, 2013.
- Flott, Jim, “Don't Plant Trees, Plant Roots”, City Trees, The Journal of the Society of Municipal Arborists, 42 (2), March/April 2006.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Municipal Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA practice credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Natives versus Cultivars
Edited by Len Phillips
How do you define which species are native to an urban area where the built environment has erased the native soil, understory plants, and wildlife that characterize a native ecosystem? Just about every arborist I know has an opinion about growing cultivars instead of native trees. Cultivars are cultivated varieties that have been selected for their different characteristics from the species. Cultivars, according to definition are stem grafted onto species rootstock, while clones would be the same selections growing on their own roots. This article will not be including clones in the comparisons below. To be perfectly clear, Red Maple, Acer rubrum is a tree native to the eastern half of the United States, while Red Sunset® Maple, Acer rubrum 'Franksred' is a cultivar that can be found growing from coast to coast in the US. I would like to offer the following comments with the hope that your opinion on this subject will be based on some facts.
Genetic features
Native – Uniform genetics in all native trees of a species being similar but having different minor characteristics.
Cultivar – Called genetically defective from the species by some experts, cultivars are genetically identical and many arborists feel they are more desirable than the native because you can rely on the desirable characteristics of form, flowers, pest resistance, etc. being identical in all the trees of a particular cultivar. In a formal landscape, all the trees would end up with an identical shape, without pruning.
Suitable for diversification
Native – Despite the uniform genetics of a native tree species, it is not enough to be considered diversified when dealing with pests and diseases. One reason to use natives is that the pest would be known and tolerated by the tree species.
Cultivar – Cultivars that have been found resistant to particular pests and diseases that attack the native trees can be used for replacing the entire urban forest and maintain proper diversification.
Long-term survival
Native – These trees were growing fine without any human interference and will continue long after humans have left the planet. They breed successfully in their home range without assistance.
Cultivar – They might become extinct without human intervention, support, and management. This would be okay because they were developed to survive in a human environment. Without humans, there is no need for these trees and the forests will revert to native species.
Growth patterns
Native – These trees have a natural form that is somewhat predictable, with minor variations in size and shape.
Cultivar – A tree's special form is one reason the tree is cross bred or selected to become a cultivar. For example, Endowment Maple, Acer saccharum 'Morton' was selected from a field of sugar maples Acer saccharum for its uniformly columnar shape.
Invasive species
Native – Invasive trees tend to be trees that have aggressive growth and reproduction functions. They are invasive because of excessive seed deployment or a high number of root suckers. In many locations, black locust, Robinia pseudoacacia is an invasive tree because of its root suckers that can destroy a hardscape or choke out understory plants.
Cultivar – Most cultivars, especially the newer introductions, do not produce viable seed and are not invasive because they must be grafted on to rootstocks, which limit their ability to spread by root suckers. Bessoniana Locust, Robinia pseudoacacia 'Bessoniana' is a non-invasive cultivar.
Planting locations
Native – Native trees grow best in native soil. Native trees can adapt to growing in poor soils because among the seedlings there will often be one seedling whose specific genotype will tolerate and grow in the poor soil.
Cultivar – Cultivars cannot adapt to poor soils unless they were selected because they were found growing in poor soil. Cultivars are often selected because they tolerate urban soils better than the native parent. Since the soils in our cities seldom resemble native soil, cultivars selected for their urban soil tolerance are clearly the best choice for planting in the city. Always grow the right tree in the right place. For example many cultivars of red maple such as, Autumn Flame Maple, Acer rubrum 'Autumn Flame' have been selected from trees growing in swampy areas. These trees are very tolerant of compacted, wet soil and soil low in oxygen; hence they make very desirable street trees (along with being one of the hardiest of the red maples and being the first to turn a brilliant red in autumn).
Unique features
Native – Native trees are seldom known for having unique features but they do provide a stable appearance to the landscape and a stable ecosystem for the flora and fauna that they support.
Cultivar – Cultivars are often selected because they have unique features dealing with forms, special flowers, large fruits, unusual leaf color, etc. Crabapple, Malus spp. is a good example of trees selected for their bloom, fruit color, wildlife food, and disease resistance of certain cultivars.
Flower Production
Native – Most native trees have normal single flowers that provide pollen and fruit for native insects and wildlife.
Cultivar – Cultivars are often selected because of outstanding flower production. However, sometimes a certain floral characteristic has bred the nectaries out of the plant. English tea roses and double flowers are a good example. This can have deleterious effect on our native pollinators and wildlife.
Uses in the urban landscape
Native – Use natives in an area of suitable, excellent soil, such as a garden or forest, to provide a uniform appearance, texture, or leaf color. Big Tooth Maple, Acer grandidentatum is a good example of a small, round tree suitable for most native landscapes.
Cultivar – Used as a street tree as well as a garden or landscape specimen, Rocky Mountain Glow® Maple, Acer grandidentatum 'Schmidt' is a good example of a cultivar that has intense autumn color and thrives in a native and an urban landscape.
Disease resistance
Native – Native trees have good resistance to common diseases through a long association with native diseases and through the genetic diversity in any long-standing natural breeding population of native trees, but they may not be able to withstand an exotic or a recently introduced diseases like Chalara fraxinea in Europe and more recently in England.
Cultivar – Many cultivars have been selected because they resist a particular disease. A good example is the Stellar Dogwood series of trees that are resistant to the Dogwood anthracnose which is killing the native eastern U.S. Dogwoods. Stellar Pink® dogwood, Cornus x 'Rutgan', is free of the disease and a very popular replacement because it offers the bonus of excellent blooms.
Pest Resistance
Native – Native trees with good resistance to certain pests are acceptable, but many exotic or introduced pests can be fatal. Some naturalists consider this a desirable feature because the pest contributes to the natural food chain. For example, the woodpecker has developed a preference for the bronze birch borer found in many native white barked birches.
Cultivar – Many cultivars have been selected because they are resistant to a devastating pest. A good example might be the Heritage® Birch, Betula nigra 'Cully', which was selected for its resistance to the bronze birch borer. What impact this may have on the woodpecker population is unknown at this time but as an apex predator the woodpecker may just move to its next favorite food item.
Global warming survival
Native – Native trees are not likely to tolerate global warming stress. The warming subjects the trees to increased disease and pest attacks. The genetic diversity of breeding native populations may somewhat buffer that species against the worst effects of warming by favoring those in its population that can adapt to changing environmental conditions. The Amur Maple, Acer ginnala might be a good example of a tree that tolerates the cold in USDA Hardiness Zone 2 and will have to migrate even further north to survive.
Cultivar – Cultivars that have been selected from warmer climates will be better survivors. An example here might be the Red November™Maple, Acer ginnala 'JFS-UGA' which is a Zone 4 tree that is heat tolerant and evolved from the heat of Georgia. However, cultivars will likely be from a narrow genetic base and as such, will not have the diverse genetic ability to adapt.
Another example of migrating trees can be found in Dealing with Climate Change by Dick Miller.
Water needs
Some naturalists claim that cultivars will require much more water use than native trees. However, a sugar maple tree and a cultivar of the same size sugar maple tree will both require the same amount of water assuming all other aspects and the physiology of the two trees is the same.
Whether you prefer natives or cultivars, keep in mind that natives define the region where you live and provide the ultimate in sustainability because they breed and survive without intervention. Cultivars provide the diversity of amenity and interest to the landscape. Another thought to consider deals with municipal budgets and that the cost to install and maintain a cultivar is almost always less than the cost to install and maintain a native tree because the cultivar was bred to survive without intervention. A cultivar can be selected as suitable for a site, instead of needing frequent maintenance and pruning that might be necessary to maintain a group of native trees in the urban environment.
Source
Editor's Note: If you know of other reasons to use natives or cultivars, please send me an email with your comments.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Municipal Specialist, Utility Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA science credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Edited by Len Phillips
How do you define which species are native to an urban area where the built environment has erased the native soil, understory plants, and wildlife that characterize a native ecosystem? Just about every arborist I know has an opinion about growing cultivars instead of native trees. Cultivars are cultivated varieties that have been selected for their different characteristics from the species. Cultivars, according to definition are stem grafted onto species rootstock, while clones would be the same selections growing on their own roots. This article will not be including clones in the comparisons below. To be perfectly clear, Red Maple, Acer rubrum is a tree native to the eastern half of the United States, while Red Sunset® Maple, Acer rubrum 'Franksred' is a cultivar that can be found growing from coast to coast in the US. I would like to offer the following comments with the hope that your opinion on this subject will be based on some facts.
Genetic features
Native – Uniform genetics in all native trees of a species being similar but having different minor characteristics.
Cultivar – Called genetically defective from the species by some experts, cultivars are genetically identical and many arborists feel they are more desirable than the native because you can rely on the desirable characteristics of form, flowers, pest resistance, etc. being identical in all the trees of a particular cultivar. In a formal landscape, all the trees would end up with an identical shape, without pruning.
Suitable for diversification
Native – Despite the uniform genetics of a native tree species, it is not enough to be considered diversified when dealing with pests and diseases. One reason to use natives is that the pest would be known and tolerated by the tree species.
Cultivar – Cultivars that have been found resistant to particular pests and diseases that attack the native trees can be used for replacing the entire urban forest and maintain proper diversification.
Long-term survival
Native – These trees were growing fine without any human interference and will continue long after humans have left the planet. They breed successfully in their home range without assistance.
Cultivar – They might become extinct without human intervention, support, and management. This would be okay because they were developed to survive in a human environment. Without humans, there is no need for these trees and the forests will revert to native species.
Growth patterns
Native – These trees have a natural form that is somewhat predictable, with minor variations in size and shape.
Cultivar – A tree's special form is one reason the tree is cross bred or selected to become a cultivar. For example, Endowment Maple, Acer saccharum 'Morton' was selected from a field of sugar maples Acer saccharum for its uniformly columnar shape.
Invasive species
Native – Invasive trees tend to be trees that have aggressive growth and reproduction functions. They are invasive because of excessive seed deployment or a high number of root suckers. In many locations, black locust, Robinia pseudoacacia is an invasive tree because of its root suckers that can destroy a hardscape or choke out understory plants.
Cultivar – Most cultivars, especially the newer introductions, do not produce viable seed and are not invasive because they must be grafted on to rootstocks, which limit their ability to spread by root suckers. Bessoniana Locust, Robinia pseudoacacia 'Bessoniana' is a non-invasive cultivar.
Planting locations
Native – Native trees grow best in native soil. Native trees can adapt to growing in poor soils because among the seedlings there will often be one seedling whose specific genotype will tolerate and grow in the poor soil.
Cultivar – Cultivars cannot adapt to poor soils unless they were selected because they were found growing in poor soil. Cultivars are often selected because they tolerate urban soils better than the native parent. Since the soils in our cities seldom resemble native soil, cultivars selected for their urban soil tolerance are clearly the best choice for planting in the city. Always grow the right tree in the right place. For example many cultivars of red maple such as, Autumn Flame Maple, Acer rubrum 'Autumn Flame' have been selected from trees growing in swampy areas. These trees are very tolerant of compacted, wet soil and soil low in oxygen; hence they make very desirable street trees (along with being one of the hardiest of the red maples and being the first to turn a brilliant red in autumn).
Unique features
Native – Native trees are seldom known for having unique features but they do provide a stable appearance to the landscape and a stable ecosystem for the flora and fauna that they support.
Cultivar – Cultivars are often selected because they have unique features dealing with forms, special flowers, large fruits, unusual leaf color, etc. Crabapple, Malus spp. is a good example of trees selected for their bloom, fruit color, wildlife food, and disease resistance of certain cultivars.
Flower Production
Native – Most native trees have normal single flowers that provide pollen and fruit for native insects and wildlife.
Cultivar – Cultivars are often selected because of outstanding flower production. However, sometimes a certain floral characteristic has bred the nectaries out of the plant. English tea roses and double flowers are a good example. This can have deleterious effect on our native pollinators and wildlife.
Uses in the urban landscape
Native – Use natives in an area of suitable, excellent soil, such as a garden or forest, to provide a uniform appearance, texture, or leaf color. Big Tooth Maple, Acer grandidentatum is a good example of a small, round tree suitable for most native landscapes.
Cultivar – Used as a street tree as well as a garden or landscape specimen, Rocky Mountain Glow® Maple, Acer grandidentatum 'Schmidt' is a good example of a cultivar that has intense autumn color and thrives in a native and an urban landscape.
Disease resistance
Native – Native trees have good resistance to common diseases through a long association with native diseases and through the genetic diversity in any long-standing natural breeding population of native trees, but they may not be able to withstand an exotic or a recently introduced diseases like Chalara fraxinea in Europe and more recently in England.
Cultivar – Many cultivars have been selected because they resist a particular disease. A good example is the Stellar Dogwood series of trees that are resistant to the Dogwood anthracnose which is killing the native eastern U.S. Dogwoods. Stellar Pink® dogwood, Cornus x 'Rutgan', is free of the disease and a very popular replacement because it offers the bonus of excellent blooms.
Pest Resistance
Native – Native trees with good resistance to certain pests are acceptable, but many exotic or introduced pests can be fatal. Some naturalists consider this a desirable feature because the pest contributes to the natural food chain. For example, the woodpecker has developed a preference for the bronze birch borer found in many native white barked birches.
Cultivar – Many cultivars have been selected because they are resistant to a devastating pest. A good example might be the Heritage® Birch, Betula nigra 'Cully', which was selected for its resistance to the bronze birch borer. What impact this may have on the woodpecker population is unknown at this time but as an apex predator the woodpecker may just move to its next favorite food item.
Global warming survival
Native – Native trees are not likely to tolerate global warming stress. The warming subjects the trees to increased disease and pest attacks. The genetic diversity of breeding native populations may somewhat buffer that species against the worst effects of warming by favoring those in its population that can adapt to changing environmental conditions. The Amur Maple, Acer ginnala might be a good example of a tree that tolerates the cold in USDA Hardiness Zone 2 and will have to migrate even further north to survive.
Cultivar – Cultivars that have been selected from warmer climates will be better survivors. An example here might be the Red November™Maple, Acer ginnala 'JFS-UGA' which is a Zone 4 tree that is heat tolerant and evolved from the heat of Georgia. However, cultivars will likely be from a narrow genetic base and as such, will not have the diverse genetic ability to adapt.
Another example of migrating trees can be found in Dealing with Climate Change by Dick Miller.
Water needs
Some naturalists claim that cultivars will require much more water use than native trees. However, a sugar maple tree and a cultivar of the same size sugar maple tree will both require the same amount of water assuming all other aspects and the physiology of the two trees is the same.
Whether you prefer natives or cultivars, keep in mind that natives define the region where you live and provide the ultimate in sustainability because they breed and survive without intervention. Cultivars provide the diversity of amenity and interest to the landscape. Another thought to consider deals with municipal budgets and that the cost to install and maintain a cultivar is almost always less than the cost to install and maintain a native tree because the cultivar was bred to survive without intervention. A cultivar can be selected as suitable for a site, instead of needing frequent maintenance and pruning that might be necessary to maintain a group of native trees in the urban environment.
Source
- Special thanks to Jay Banks and David Lloyd-Jones for their comments on this subject.
- Audubon at Home, “Plant Native Species”, National Audubon Society, Inc., 2013.
- Lloyd -Jones, David, “Tree Morphogenesis Book 1 Reduction Via Thinning” Kindle Edition, Chapter 8, 2013.
- Ramstad, Kristin and Cynthia Orlando, “Tree Choices: Native? Non-native? Invasive? The terms can be relative”, Oregon Department of Forestry Urban and Community Forestry Assistance Program, 2009.
Editor's Note: If you know of other reasons to use natives or cultivars, please send me an email with your comments.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Municipal Specialist, Utility Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA science credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Tales About Oaks
by Len Phillips
Before the arrival of Europeans, 91 species of oaks (Quercus sp.) covered much of the US. The genus offers 530 species world-wide that come in evergreen, deciduous, tree, and shrub forms. They grow in sunny, open forests such as savannas and woodlands from cold to tropical climates. Today there is an oak for almost any landscape where space allows. Quercus can be found in many forms and shapes such as pyramidal, columnar, oval, round, vase, irregular, broad, and shrubby. There is a species that will grow in very wet swampy soils and a species that will tolerate a hot dry desert, but most species grow in average soils everywhere in-between. Oaks are also considered to be excellent soil builders and they also anchor the soil and offer shade to other diverse species in the forest as well as the urban landscapes.
If any tree deserves to be called the “tree of life,” it is Quercus. For thousands of years, the world’s oaks have provided food and shelter for a multitude of wildlife species. In many forests, they also play key ecological roles, dominating the forest canopy and determining which plants can grow on the ground underneath their spreading canopy. Periodic wildfires in the US and burning by Native Americans gave these fire-resistant trees an edge, removing woody competitors and creating clearings for acorns to sprout and sun-loving Quercus seedlings and saplings to thrive.
Population Changes
When the Europeans arrived in the 1600's and early 1700's, the oak forests in the Americas began to decline. The forests were razed to make way for crops, pasture land and development by early settlers. Quercus species are now being ravaged by climate change, diseases, and pests. Historically, forests in the east-central United States were about 55% oaks. Today that percentage has shrunk to about 25%. Oaks are now a fraction of what they once were, and those that remain are declining rapidly. In a recent analysis, Morton Arboretum scientists found that 28 of the nation’s 91 native Quercus species are on the edge of extinction. By far the most lethal cause of this decline is sudden oak death, which hitchhiked into this country on imported nursery stock. First observed in the mid-1990s, the disease has killed millions of oak and tanoak (Notholithocarpus densiflorus) trees in California and Oregon. Now foresters are preparing for its inevitable onslaught in the Midwest and eventually to the East Coast, where oaks already are afflicted by a variety of pests and pathogens. The pests include everything from the non-native gypsy moth to oak wilt, a fungal disease that kills thousands of oaks every year. Pests and diseases will probably be a much bigger factor in a decade or two as oak trees become more stressed by global warming.
Climate change already threatens all U.S. Quercus species of conservation concern. Because they are so long-lived and have long reproductive cycles, oak populations do not migrate very far, or very fast, so they are unlikely to keep pace with rapidly changing climate conditions especially global warming.
Impact on Wildlife
Another concern for the survival of Quercus, is Oak decline which imperils the wildlife that depend on these trees. Oak loss in the United Kingdom already threatens the survival of 2,300 species of mammals, birds, invertebrates and fungi. In the United States, scientists estimate that acorns are critical to the diets of more than 100 vertebrates, from wood ducks to black bears to deer. But not the wild turkey population. It has grown so large that turkeys are becoming annoying pests in many cities because they get the acorns faster than other animals and are not afraid to stand in the middle of a busy street to get an acorn the fell from a nearby tree.
Oaks support 934 species of caterpillars, which is an essential food for songbirds. As the oak habitats have disappeared, species such as the northern bobwhite, prairie warbler, white-eyed vireo and yellow-breasted chat have undergone consistent declines during the past 50 years.
Impact on Other Plants
Quercus savannas and woodlands were once carpeted by a rich diversity of sun-loving wildflowers and grasses, from big bluestem, woodland sunflower and aster to hazelnut and blueberry. As shade-tolerant trees colonize open forests and their canopies close, the array of ground flora are in decline.
Solution
To help oaks recover, scientists recommend more use of forest management strategies such as prescribed burning and canopy thinning to give oaks the light they need. Homeowners and cities can also play a role by planting native Quercus, which also helps the local wildlife.
The Society of Municipal Arborists has been selecting an Urban Tree of the Year for the past 25 years. During that time, 5 of those trees have been oaks. This tree's popularity comes from the many unique features of the Quercus species and their ability to tolerate the urban environment. The many recent introductions of cultivars and hybrids by the nursery industry are greatly expanding the popularity of the oak tree. This is proof positive that there is an opportunity for Quercus to not only survive but to thrive in our cities.
Sources
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Municipal Specialist, Utility Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA science and management credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
by Len Phillips
Before the arrival of Europeans, 91 species of oaks (Quercus sp.) covered much of the US. The genus offers 530 species world-wide that come in evergreen, deciduous, tree, and shrub forms. They grow in sunny, open forests such as savannas and woodlands from cold to tropical climates. Today there is an oak for almost any landscape where space allows. Quercus can be found in many forms and shapes such as pyramidal, columnar, oval, round, vase, irregular, broad, and shrubby. There is a species that will grow in very wet swampy soils and a species that will tolerate a hot dry desert, but most species grow in average soils everywhere in-between. Oaks are also considered to be excellent soil builders and they also anchor the soil and offer shade to other diverse species in the forest as well as the urban landscapes.
If any tree deserves to be called the “tree of life,” it is Quercus. For thousands of years, the world’s oaks have provided food and shelter for a multitude of wildlife species. In many forests, they also play key ecological roles, dominating the forest canopy and determining which plants can grow on the ground underneath their spreading canopy. Periodic wildfires in the US and burning by Native Americans gave these fire-resistant trees an edge, removing woody competitors and creating clearings for acorns to sprout and sun-loving Quercus seedlings and saplings to thrive.
Population Changes
When the Europeans arrived in the 1600's and early 1700's, the oak forests in the Americas began to decline. The forests were razed to make way for crops, pasture land and development by early settlers. Quercus species are now being ravaged by climate change, diseases, and pests. Historically, forests in the east-central United States were about 55% oaks. Today that percentage has shrunk to about 25%. Oaks are now a fraction of what they once were, and those that remain are declining rapidly. In a recent analysis, Morton Arboretum scientists found that 28 of the nation’s 91 native Quercus species are on the edge of extinction. By far the most lethal cause of this decline is sudden oak death, which hitchhiked into this country on imported nursery stock. First observed in the mid-1990s, the disease has killed millions of oak and tanoak (Notholithocarpus densiflorus) trees in California and Oregon. Now foresters are preparing for its inevitable onslaught in the Midwest and eventually to the East Coast, where oaks already are afflicted by a variety of pests and pathogens. The pests include everything from the non-native gypsy moth to oak wilt, a fungal disease that kills thousands of oaks every year. Pests and diseases will probably be a much bigger factor in a decade or two as oak trees become more stressed by global warming.
Climate change already threatens all U.S. Quercus species of conservation concern. Because they are so long-lived and have long reproductive cycles, oak populations do not migrate very far, or very fast, so they are unlikely to keep pace with rapidly changing climate conditions especially global warming.
Impact on Wildlife
Another concern for the survival of Quercus, is Oak decline which imperils the wildlife that depend on these trees. Oak loss in the United Kingdom already threatens the survival of 2,300 species of mammals, birds, invertebrates and fungi. In the United States, scientists estimate that acorns are critical to the diets of more than 100 vertebrates, from wood ducks to black bears to deer. But not the wild turkey population. It has grown so large that turkeys are becoming annoying pests in many cities because they get the acorns faster than other animals and are not afraid to stand in the middle of a busy street to get an acorn the fell from a nearby tree.
Oaks support 934 species of caterpillars, which is an essential food for songbirds. As the oak habitats have disappeared, species such as the northern bobwhite, prairie warbler, white-eyed vireo and yellow-breasted chat have undergone consistent declines during the past 50 years.
Impact on Other Plants
Quercus savannas and woodlands were once carpeted by a rich diversity of sun-loving wildflowers and grasses, from big bluestem, woodland sunflower and aster to hazelnut and blueberry. As shade-tolerant trees colonize open forests and their canopies close, the array of ground flora are in decline.
Solution
To help oaks recover, scientists recommend more use of forest management strategies such as prescribed burning and canopy thinning to give oaks the light they need. Homeowners and cities can also play a role by planting native Quercus, which also helps the local wildlife.
The Society of Municipal Arborists has been selecting an Urban Tree of the Year for the past 25 years. During that time, 5 of those trees have been oaks. This tree's popularity comes from the many unique features of the Quercus species and their ability to tolerate the urban environment. The many recent introductions of cultivars and hybrids by the nursery industry are greatly expanding the popularity of the oak tree. This is proof positive that there is an opportunity for Quercus to not only survive but to thrive in our cities.
Sources
- Dirr, Michael A. and Keith S. Warren, “The Tree Book”, Timber Press, 2019.
- Wikipedia, Quercus, January 2020.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Municipal Specialist, Utility Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA science and management credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
The Secret of Tree Longevity
Edited by Len Phillips
Ginkgo biloba is a living fossil. It is the oldest surviving tree species, having remained on the planet, relatively unchanged for some 200 million years. Today, a single ginkgo may live for hundreds of years, maybe more than a thousand. They have survived some of the world’s greatest catastrophes, from the extinction of the dinosaurs to enduring the atomic bombing of Hiroshima. An example of how tough the ginkgo tree can be, look at Hiroshima, Japan, where six trees growing a short distance from the 1945 atomic bomb explosion and were among the few living things in the area that survived the blast. Although charred, they quickly recovered and were soon healthy and growing again. The six survivor trees are still alive today.
Another ginkgo growing beside a rice field was trimmed back because it was shading the rice. The removed branches were burned and the tree itself caught fire and appeared to have died, but it was not removed. Twenty years later it began to send out leaves and it is still alive today.
So what’s the secret to their longevity? In humans, as we age, our immune system begins to weaken. But in a way, the immune system in the ginkgo, even if they are a 1,000 years old, looks the same as that of a 20-year-old tree. Scientists in China and the United States compared young and old Ginkgo trees, ranging in age from 15 to 1,300 years old, in a study of the genetics of the vascular cambium, a layer or cylinder of living cells behind the bark. In the rings and genes of Ginkgo trees in China, some of which are confirmed to be more than 1,000 years old, scientists found that the Ginkgo grows wide rings indefinitely through old age. That is because the genes in the cambium contain no program for senescence, or death, but continue their program for making defenses even after hundreds of years. Old trees also produce just as many seeds and their leaves are just as resourceful as those of young trees.
Though it has yet to be tested, researchers believe other old trees such as the 4,800-year-old Pinus longaeva bristlecone pine known as Methuselah in eastern California, may have a similar pattern of genetic programming like the ginkgo. Although ginkgoes and the bristlecone live long, they do age.
Thus, while a tree that has lived for centuries might appear dilapidated due to frost damage or lightning strikes, all the processes needed for healthy growth are still functioning. Researchers suspect the picture will be similar in other long-lived trees, such as the giant redwood, which has wood packed with anti-microbial chemicals.
Apart from a consistent supply of food, light and water, the ability of the Ginkgo to live to a great age and large size is thought to be linked to its slow growth rate, cellular adaptations and relative protection from secondary influences such as pests and diseases, climate extremes and catastrophic physical damage.
The trees grow up and out. Up, with a cell-generating region called the apical meristem, and out, with the vascular cambium. Over time, weather or other things damage the apical meristem, limiting a tree’s height. And each year, leaves die and fall off. But the Ginkgo cambium, contained within the tree’s trunk, remains intact and active. Cell division tends to slow down after the age of 200, but the cells are still viable. They generate defenses and carry water and nutrients so the tree grows and stays healthy. However, sometimes trees may be reduced to just hollow stumps, but with the cambium intact, they can still produce leaves and flowers or even live as stumps.
Essentially, trees like ginkgo could live forever. Being modular organisms, every year the ginkgo puts on new wood, new roots, new leaves, new sex organs. Trees like redwoods or Methuselah would produce similar results.
Sources
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Municipal Specialist, Utility Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA science credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Edited by Len Phillips
Ginkgo biloba is a living fossil. It is the oldest surviving tree species, having remained on the planet, relatively unchanged for some 200 million years. Today, a single ginkgo may live for hundreds of years, maybe more than a thousand. They have survived some of the world’s greatest catastrophes, from the extinction of the dinosaurs to enduring the atomic bombing of Hiroshima. An example of how tough the ginkgo tree can be, look at Hiroshima, Japan, where six trees growing a short distance from the 1945 atomic bomb explosion and were among the few living things in the area that survived the blast. Although charred, they quickly recovered and were soon healthy and growing again. The six survivor trees are still alive today.
Another ginkgo growing beside a rice field was trimmed back because it was shading the rice. The removed branches were burned and the tree itself caught fire and appeared to have died, but it was not removed. Twenty years later it began to send out leaves and it is still alive today.
So what’s the secret to their longevity? In humans, as we age, our immune system begins to weaken. But in a way, the immune system in the ginkgo, even if they are a 1,000 years old, looks the same as that of a 20-year-old tree. Scientists in China and the United States compared young and old Ginkgo trees, ranging in age from 15 to 1,300 years old, in a study of the genetics of the vascular cambium, a layer or cylinder of living cells behind the bark. In the rings and genes of Ginkgo trees in China, some of which are confirmed to be more than 1,000 years old, scientists found that the Ginkgo grows wide rings indefinitely through old age. That is because the genes in the cambium contain no program for senescence, or death, but continue their program for making defenses even after hundreds of years. Old trees also produce just as many seeds and their leaves are just as resourceful as those of young trees.
Though it has yet to be tested, researchers believe other old trees such as the 4,800-year-old Pinus longaeva bristlecone pine known as Methuselah in eastern California, may have a similar pattern of genetic programming like the ginkgo. Although ginkgoes and the bristlecone live long, they do age.
Thus, while a tree that has lived for centuries might appear dilapidated due to frost damage or lightning strikes, all the processes needed for healthy growth are still functioning. Researchers suspect the picture will be similar in other long-lived trees, such as the giant redwood, which has wood packed with anti-microbial chemicals.
Apart from a consistent supply of food, light and water, the ability of the Ginkgo to live to a great age and large size is thought to be linked to its slow growth rate, cellular adaptations and relative protection from secondary influences such as pests and diseases, climate extremes and catastrophic physical damage.
The trees grow up and out. Up, with a cell-generating region called the apical meristem, and out, with the vascular cambium. Over time, weather or other things damage the apical meristem, limiting a tree’s height. And each year, leaves die and fall off. But the Ginkgo cambium, contained within the tree’s trunk, remains intact and active. Cell division tends to slow down after the age of 200, but the cells are still viable. They generate defenses and carry water and nutrients so the tree grows and stays healthy. However, sometimes trees may be reduced to just hollow stumps, but with the cambium intact, they can still produce leaves and flowers or even live as stumps.
Essentially, trees like ginkgo could live forever. Being modular organisms, every year the ginkgo puts on new wood, new roots, new leaves, new sex organs. Trees like redwoods or Methuselah would produce similar results.
Sources
- Richard Dixon, a biologist at the University of North Texas.
- Peter Crane, an evolutionary biologist and author of “Ginkgo: The Tree that Time Forgot and soon to be published “The Riddle of Kew's Sexually Confused Ginkgo Solved”
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Municipal Specialist, Utility Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA science credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
What is Biochar?
Edited by Len Phillips
Biochar is an ancient, yet newly rediscovered soil amendment that is being promoted around the US as gardeners, farmers, and plant lovers of all types learn of the intriguing properties and benefits of biochar added to the soil. It is basically the same product as charcoal but the main difference is its use. Charcoal is used as a fuel, and biochar is used as a soil amendment that aids in sequestering carbon. Biochar in the soil promotes vigorous growth in trees and most other plants.
Arborists have begun to learn about how to use biochar as a soil amendment to solve some common soil problems such as low organic matter in disturbed soils, soil compaction, soil water retention, and nutrient leaching. Biochar is not activated carbon, but it does have some similar characteristics, including a large surface area that is chemically active. It takes biochar hundreds to thousands of years to break down, forming a kind of semi-permanent compost. The longevity of the biochar comes from its being highly stable in the soil.
How is Biochar Made?
Biochar is derived from biomass such as wood chips, crop residues, and manures processed by pyrolysis. Pyrolysis is decomposition brought about by high temperatures in a low or no-oxygen environment to produce a carbon-enriched charcoal that promotes microbial activity when it contacts soil.
That is the basic biochar making process, but the end product is not a single, well defined substance. Depending on the time and temperature, different biochars can have very different properties. Biochar can tie up substantial amounts of carbon from the carbon dioxide in the Earth's atmosphere, reducing the effects of global warming in a minor way. Biochar is clean and safe to use in soil, although reaching the full benefits of biochar will require decades. It takes biochar hundreds to thousands of years to break down, forming a kind of semi-permanent soil amendment.
Tree Roots and Biochar
Fused carbon rings form the micro-structure of the common form of biochar. This structure supports soil fungal and bacterial life while holding water and nutrients. Plant roots love it, and with proper nutrient support, plants of all kinds including trees, seem to thrive in biochar. A coarser form is highly porous and has robust ion-exchange properties.
How Does Biochar Work?
Professional arborists in Japan use biochar applications in root-zone trenches to revive the much-loved ancient trees on the grounds of temples and shrines. These trees suffer from soil compaction caused by visitor’s feet. Prior to application, the biochar is inoculated with mycorrhizal fungi and nutrients. Research shows that biochar increases the abundance of mycorrhizal fungi in soil, and this allows the roots to grow and relieve the compaction. Inoculated biochar has also become a popular ingredient in nursery media for increased tree seedling survival and growth.
It appears that biochar additions would be positive for urban sites to:
Black Soil
Black soil sites are the accumulation of centuries of man-induced biochar created by ‘slash and burn’ agriculture or the depositing of “garbage” and fire remains by prehistoric inhabitants. On the black soil sites with the highest fertility, there is clear evidence to the site having multi-millennia of activity.
Biochar v. Charcoal
The issue of charcoal vs. biochar is real and distinct. Although they are both made from carbon, charcoal production is a ‘hot fire” procedure; all volatiles are consumed and expelled. It is pure carbon and inert.
Biochar production is low heat, often wet wood, partially consumed. Nearly all the K and much of the N are retained. Commercial charcoal is heartwood and slabs. Much of the biochar is “slash” and vegetative matter. Throwing partially crushed charcoal into the soil will have a physical contribution, but it lacks the complexity and the reactive longevity of biochar.
Research Results
In the US, biochar research has begun to move out of the universities and government labs and into the hands of professional arborists. Researchers found clear improvements using biochar amendments, particularly in sandy soils where biochar's water holding capacity is a big boost.
Researchers have also found that it can take several years for biochar to accumulate nutrients and boost soil life. Often the greatest effects are not seen until the second or third year after a biochar application. For long-lived species such as trees, this feature of biochar is an important benefit with the potential to reduce care and maintenance needs over the long term.
Biochar Application Techniques
Applying biochar to planting holes can improve the growth of trees and reduce transplant shock. When applying biochar to planting holes, mix the biochar with the backfill soil, and do not apply very large amounts of biochar.
Researchers are focused on looking for the most economical and effective methods for adding biochar to the soil. Some recent studies have looked at:
Biochar research on vegetable plants found that the product-amended plants seemed to develop a strong resistance to disease. Biochar gardens also exhibited less water stress than untreated plants.
Given the variables in biochar material and compounds, tree care professionals can provide substantial value to tree plantings by following the research and development of biochar and learning about successful applications. Ideally, biochar should comprise about 8% to 10% of soil volume.
Biochar for the Future
Biochar has additional potential benefits of bioenergy production and carbon sequestration. Instead of a wood chipper with the urban forestry and arboriculture crews, they might be well suited for mobile units that provide fast-pyrolysis systems that could convert urban wood waste into bio-oil, syngas, and biochar. Units could be strategically located at or near biomass removal locations to convert low-value urban wood waste into easily stored and transportable fuel to be used for heat, power, and chemical production. The biochar produced could then be returned to the site as a means for improving urban soil quality and storing carbon in the soil. Research is still in its infancy on the economic feasibility of bioenergy production systems and biochar application using residual woody biomass from forest management activities, but these efforts may be useful for adaptation to the urban forest wood utilization.
Sources
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Municipal Specialist, Utility Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA science credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Edited by Len Phillips
Biochar is an ancient, yet newly rediscovered soil amendment that is being promoted around the US as gardeners, farmers, and plant lovers of all types learn of the intriguing properties and benefits of biochar added to the soil. It is basically the same product as charcoal but the main difference is its use. Charcoal is used as a fuel, and biochar is used as a soil amendment that aids in sequestering carbon. Biochar in the soil promotes vigorous growth in trees and most other plants.
Arborists have begun to learn about how to use biochar as a soil amendment to solve some common soil problems such as low organic matter in disturbed soils, soil compaction, soil water retention, and nutrient leaching. Biochar is not activated carbon, but it does have some similar characteristics, including a large surface area that is chemically active. It takes biochar hundreds to thousands of years to break down, forming a kind of semi-permanent compost. The longevity of the biochar comes from its being highly stable in the soil.
How is Biochar Made?
Biochar is derived from biomass such as wood chips, crop residues, and manures processed by pyrolysis. Pyrolysis is decomposition brought about by high temperatures in a low or no-oxygen environment to produce a carbon-enriched charcoal that promotes microbial activity when it contacts soil.
That is the basic biochar making process, but the end product is not a single, well defined substance. Depending on the time and temperature, different biochars can have very different properties. Biochar can tie up substantial amounts of carbon from the carbon dioxide in the Earth's atmosphere, reducing the effects of global warming in a minor way. Biochar is clean and safe to use in soil, although reaching the full benefits of biochar will require decades. It takes biochar hundreds to thousands of years to break down, forming a kind of semi-permanent soil amendment.
Tree Roots and Biochar
Fused carbon rings form the micro-structure of the common form of biochar. This structure supports soil fungal and bacterial life while holding water and nutrients. Plant roots love it, and with proper nutrient support, plants of all kinds including trees, seem to thrive in biochar. A coarser form is highly porous and has robust ion-exchange properties.
How Does Biochar Work?
Professional arborists in Japan use biochar applications in root-zone trenches to revive the much-loved ancient trees on the grounds of temples and shrines. These trees suffer from soil compaction caused by visitor’s feet. Prior to application, the biochar is inoculated with mycorrhizal fungi and nutrients. Research shows that biochar increases the abundance of mycorrhizal fungi in soil, and this allows the roots to grow and relieve the compaction. Inoculated biochar has also become a popular ingredient in nursery media for increased tree seedling survival and growth.
It appears that biochar additions would be positive for urban sites to:
- improve nutrient availability,
- reduce nutrient leaching and fertilizer requirements,
- reduce soil acidity,
- improve water quality,
- reduce stormwater runoff and irrigation needs because it holds free water,
- increase soil particle surfaces and reduce soil emissions of greenhouse gases,
- be active in soil physics, chemistry and biology, unlike vermiculite or expandable shale,
- resist soil compression,
- reuse organic waste,
- enhance damaged city soils without importing expensive sands and aggregates to aerate compacted soil,
- depreciate structurally over time to become enriched sub-soil.
Black Soil
Black soil sites are the accumulation of centuries of man-induced biochar created by ‘slash and burn’ agriculture or the depositing of “garbage” and fire remains by prehistoric inhabitants. On the black soil sites with the highest fertility, there is clear evidence to the site having multi-millennia of activity.
Biochar v. Charcoal
The issue of charcoal vs. biochar is real and distinct. Although they are both made from carbon, charcoal production is a ‘hot fire” procedure; all volatiles are consumed and expelled. It is pure carbon and inert.
Biochar production is low heat, often wet wood, partially consumed. Nearly all the K and much of the N are retained. Commercial charcoal is heartwood and slabs. Much of the biochar is “slash” and vegetative matter. Throwing partially crushed charcoal into the soil will have a physical contribution, but it lacks the complexity and the reactive longevity of biochar.
Research Results
In the US, biochar research has begun to move out of the universities and government labs and into the hands of professional arborists. Researchers found clear improvements using biochar amendments, particularly in sandy soils where biochar's water holding capacity is a big boost.
Researchers have also found that it can take several years for biochar to accumulate nutrients and boost soil life. Often the greatest effects are not seen until the second or third year after a biochar application. For long-lived species such as trees, this feature of biochar is an important benefit with the potential to reduce care and maintenance needs over the long term.
Biochar Application Techniques
Applying biochar to planting holes can improve the growth of trees and reduce transplant shock. When applying biochar to planting holes, mix the biochar with the backfill soil, and do not apply very large amounts of biochar.
Researchers are focused on looking for the most economical and effective methods for adding biochar to the soil. Some recent studies have looked at:
- soil auguring and filling the holes with a biochar (“vertical mulching”).
- air spade excavation and mixing biochar into the soil being backfilled, has resulted in physical compaction improvement.
- liquid injection of a fine biochar/water slurry using existing fertigation technologies. The liquid injection method looks promising in preliminary research results.
- biochar can be applied in trenches radiating out from the base of established trees (“radial trenching”).
- broadcast spreading over the soil surface can be done by hand or by using spreaders or broadcast seeders.
- plowing is not recommended as it is unlikely to mix the biochar into the soil and may result in deep biochar layers.
Biochar research on vegetable plants found that the product-amended plants seemed to develop a strong resistance to disease. Biochar gardens also exhibited less water stress than untreated plants.
Given the variables in biochar material and compounds, tree care professionals can provide substantial value to tree plantings by following the research and development of biochar and learning about successful applications. Ideally, biochar should comprise about 8% to 10% of soil volume.
Biochar for the Future
Biochar has additional potential benefits of bioenergy production and carbon sequestration. Instead of a wood chipper with the urban forestry and arboriculture crews, they might be well suited for mobile units that provide fast-pyrolysis systems that could convert urban wood waste into bio-oil, syngas, and biochar. Units could be strategically located at or near biomass removal locations to convert low-value urban wood waste into easily stored and transportable fuel to be used for heat, power, and chemical production. The biochar produced could then be returned to the site as a means for improving urban soil quality and storing carbon in the soil. Research is still in its infancy on the economic feasibility of bioenergy production systems and biochar application using residual woody biomass from forest management activities, but these efforts may be useful for adaptation to the urban forest wood utilization.
Sources
- “Amazonian Terra Preta Can Transform Poor Soil Into Fertile” Science Daily, Mar. 1, 2006.
- Conversations with participants of LinkedIn's Urban Forestry Discussion Group, 2011 and 2014.
- Major, Julie PhD, “Practical aspects of biochar application to tree crops”, IBI Technical Bulletin #102, 2010.
- Wilson, Kelpie, “Biochar for Arborists”, Tree Care Industry, September 2012.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Municipal Specialist, Utility Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA science credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.