Seminar #81 from Online Seminars for Municipal Arborists
January - March 2019
Sections Go directly to the section by clicking on the title below
January - March 2019
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.
Halifax, Nova Scotia
by Peter Duinker and John Simmons
The City of Halifax, officially known as the Halifax Regional Municipality (HRM), is the capital of the Canadian province of Nova Scotia. The municipality has a population of 403,131 with 316,701 in the urban area centered on Halifax Harbor.
The four municipalities in the HRM urban area had been coordinating service delivery through the Metropolitan Authority since the late 1970s, but remained independent towns and cities until April 1, 1996, when the provincial government amalgamated all municipal governments within Halifax County to create the Halifax Regional Municipality. Thus, the municipal boundary now includes all of Halifax County except for several First Nation reserves.
HRM is a major economic center in Atlantic Canada with a large concentration of government services and private sector companies in the city. Agriculture, fishing, mining, forestry, and natural gas extraction are the major resource industries found in the municipality.
Halifax Explosion
Halifax also has strong ties to the United States. In December 1917, Halifax experienced one of the greatest disasters in Canadian history. The SS Mont-Blanc, a French cargo ship carrying munitions for the war effort in Europe, collided with the Belgian Relief vessel SS Imo in "The Narrows" between upper Halifax Harbor and Bedford Basin. The resulting blast, called the “Halifax Explosion”, devastated the Richmond District of Halifax, killing approximately 2,000 people and injuring nearly 9,000 others. The blast levelled most of the buildings and trees in the area and was the largest artificial explosion in the world before the development of nuclear weapons. Many of the wounded were blinded by flying glass as they turned to see what caused the blast.
Significant aid came from Boston, Massachusetts to help the city, and this effort strengthened the bond between the two coastal cities. For decades since then, at the beginning of every Christmas season the citizens of Halifax thank the citizens of Boston by transporting a large evergreen tree from Halifax to Boston. Before leaving, the tree is celebrated in Halifax with a farewell tour of the region as people come out to see the tree being trucked from where it was cut down, to Halifax where it is the focus of a celebration. After celebrating the tree, it makes the journey to Boston Common where it is set up and decorated for the holiday season. The lighting of the tree is also a major celebration in Boston.
Municipal Parks
Getting back to Halifax, HRM has six large municipal woodland parks all of which contain old growth forest. The most visited park, with well over a million visitors a year, is Point Pleasant Park. This park has over 170 acres (70 hectares) of mostly woodland. In 2003, this park suffered the loss of about 75 percent of its mature trees, (white pine, red spruce, and eastern hemlock), many of which were well over 100 years old. This loss was due to Hurricane Juan. While the forest rebounds, the park is rich with single old trees still standing but it also has a huge population of large snags (dead standing trees).
When the Point Pleasant Park Comprehensive Plan was completed in 2008, it specified that all old trees will remain standing unless they represent a hazard to park users who are walking on the park’s dense roadway and path network. As for snags, only those within about 65 feet (20 meters) of the paths and roadways are maintained. All the rest remain standing until nature fells them. When a large tree near a path or roadway dies, arborists remove all the branches and leave the main stem standing perhaps up to 50 ft (15 m) tall. These snags serve to provide several important biodiversity functions, which park users appreciate. When the stem has deteriorated to such an extent that the risk of falling naturally is significant, the stem is felled and laid on the forest floor near the path. At first, park users would remark that the standing dead trees looked ugly. But once they understood the ecological value of old trees, both living and dead, their attitudes changed. Park users are now quite comfortable with this management regime.
It is important to realize that most of the park is woodland with a predominant regenerating forest. Park users do not generally walk off the paths and roadways. A few parts of the park have mowed grass. These small areas are where many people spend time with friends for quiet recreation. Near the seashore, tree management is more aggressive to secure the safety of park users. Interested persons are encouraged to examine the satellite imagery on Google maps to see, in synoptic view, what the park forest looks like.
HRM Urban Forestry
The HRM Urban Forestry staff consist of 14 arborists, one leadhand (foreman), one supervisor and a Superintendent of Urban Forestry. The equipment consists of four aerial lifts, a chipper truck, four – 18 inch chippers, a stump grinder, and an assortment of small trucks. The annual budget is approximately 3 million dollars (Canadian) of which $650,000 is directed to planting, $650,000 is directed to implementation of the cyclic pruning program, and the rest is used for wages, equipment, and materials. The HRM Urban Forestry Program aggressively incorporates the industry's best practices.
The implementation of the urban forest master plan (UFMP) is currently in its 6th year. The plan is actively followed and is tweaked as needed. HRM partnered with Dalhousie University to create the plan in 2010-2012 and continues this collaboration to support research and monitoring during plan implementation.
Street Trees
The UFMP also estimated that 709,000 publicly-owned trees line the urban streets of HRM. Of these, 157,000 were directly planted and managed, while the other 552,000 were naturally regenerated trees along HRM roadways. Despite this abundance, the research shows there are still 94,000 vacant spots for trees on HRM controlled rights of way.
A study also detailed the economic benefits of the urban forest. For example, about 1,478 metric tons of pollutants are removed annually by urban trees and shrubs in the serviced area of HRM. This equates to $9.6 (C) million each year in air pollution mitigation benefits. The research also showed that HRM’s street trees saved $12.4 million in energy costs each year. The shade provided by urban trees can reduce the total energy required to cool a building. This cooling effect not only reduces energy costs, it also translates into reduced air emissions associated with air conditioning. Our street trees also play an essential role in moderating stormwater and flood damage, water quality, erosion, and stormwater treatment costs. In HRM, it is estimated that street trees provide about $2.1 million in stormwater reduction services annually.
The HRM Urban Forestry staff takes pride in being one of the leading urban forestry departments in Canada and plans to continue being a leader well into the future.
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.
by Peter Duinker and John Simmons
The City of Halifax, officially known as the Halifax Regional Municipality (HRM), is the capital of the Canadian province of Nova Scotia. The municipality has a population of 403,131 with 316,701 in the urban area centered on Halifax Harbor.
The four municipalities in the HRM urban area had been coordinating service delivery through the Metropolitan Authority since the late 1970s, but remained independent towns and cities until April 1, 1996, when the provincial government amalgamated all municipal governments within Halifax County to create the Halifax Regional Municipality. Thus, the municipal boundary now includes all of Halifax County except for several First Nation reserves.
HRM is a major economic center in Atlantic Canada with a large concentration of government services and private sector companies in the city. Agriculture, fishing, mining, forestry, and natural gas extraction are the major resource industries found in the municipality.
Halifax Explosion
Halifax also has strong ties to the United States. In December 1917, Halifax experienced one of the greatest disasters in Canadian history. The SS Mont-Blanc, a French cargo ship carrying munitions for the war effort in Europe, collided with the Belgian Relief vessel SS Imo in "The Narrows" between upper Halifax Harbor and Bedford Basin. The resulting blast, called the “Halifax Explosion”, devastated the Richmond District of Halifax, killing approximately 2,000 people and injuring nearly 9,000 others. The blast levelled most of the buildings and trees in the area and was the largest artificial explosion in the world before the development of nuclear weapons. Many of the wounded were blinded by flying glass as they turned to see what caused the blast.
Significant aid came from Boston, Massachusetts to help the city, and this effort strengthened the bond between the two coastal cities. For decades since then, at the beginning of every Christmas season the citizens of Halifax thank the citizens of Boston by transporting a large evergreen tree from Halifax to Boston. Before leaving, the tree is celebrated in Halifax with a farewell tour of the region as people come out to see the tree being trucked from where it was cut down, to Halifax where it is the focus of a celebration. After celebrating the tree, it makes the journey to Boston Common where it is set up and decorated for the holiday season. The lighting of the tree is also a major celebration in Boston.
Municipal Parks
Getting back to Halifax, HRM has six large municipal woodland parks all of which contain old growth forest. The most visited park, with well over a million visitors a year, is Point Pleasant Park. This park has over 170 acres (70 hectares) of mostly woodland. In 2003, this park suffered the loss of about 75 percent of its mature trees, (white pine, red spruce, and eastern hemlock), many of which were well over 100 years old. This loss was due to Hurricane Juan. While the forest rebounds, the park is rich with single old trees still standing but it also has a huge population of large snags (dead standing trees).
When the Point Pleasant Park Comprehensive Plan was completed in 2008, it specified that all old trees will remain standing unless they represent a hazard to park users who are walking on the park’s dense roadway and path network. As for snags, only those within about 65 feet (20 meters) of the paths and roadways are maintained. All the rest remain standing until nature fells them. When a large tree near a path or roadway dies, arborists remove all the branches and leave the main stem standing perhaps up to 50 ft (15 m) tall. These snags serve to provide several important biodiversity functions, which park users appreciate. When the stem has deteriorated to such an extent that the risk of falling naturally is significant, the stem is felled and laid on the forest floor near the path. At first, park users would remark that the standing dead trees looked ugly. But once they understood the ecological value of old trees, both living and dead, their attitudes changed. Park users are now quite comfortable with this management regime.
It is important to realize that most of the park is woodland with a predominant regenerating forest. Park users do not generally walk off the paths and roadways. A few parts of the park have mowed grass. These small areas are where many people spend time with friends for quiet recreation. Near the seashore, tree management is more aggressive to secure the safety of park users. Interested persons are encouraged to examine the satellite imagery on Google maps to see, in synoptic view, what the park forest looks like.
HRM Urban Forestry
The HRM Urban Forestry staff consist of 14 arborists, one leadhand (foreman), one supervisor and a Superintendent of Urban Forestry. The equipment consists of four aerial lifts, a chipper truck, four – 18 inch chippers, a stump grinder, and an assortment of small trucks. The annual budget is approximately 3 million dollars (Canadian) of which $650,000 is directed to planting, $650,000 is directed to implementation of the cyclic pruning program, and the rest is used for wages, equipment, and materials. The HRM Urban Forestry Program aggressively incorporates the industry's best practices.
The implementation of the urban forest master plan (UFMP) is currently in its 6th year. The plan is actively followed and is tweaked as needed. HRM partnered with Dalhousie University to create the plan in 2010-2012 and continues this collaboration to support research and monitoring during plan implementation.
Street Trees
The UFMP also estimated that 709,000 publicly-owned trees line the urban streets of HRM. Of these, 157,000 were directly planted and managed, while the other 552,000 were naturally regenerated trees along HRM roadways. Despite this abundance, the research shows there are still 94,000 vacant spots for trees on HRM controlled rights of way.
A study also detailed the economic benefits of the urban forest. For example, about 1,478 metric tons of pollutants are removed annually by urban trees and shrubs in the serviced area of HRM. This equates to $9.6 (C) million each year in air pollution mitigation benefits. The research also showed that HRM’s street trees saved $12.4 million in energy costs each year. The shade provided by urban trees can reduce the total energy required to cool a building. This cooling effect not only reduces energy costs, it also translates into reduced air emissions associated with air conditioning. Our street trees also play an essential role in moderating stormwater and flood damage, water quality, erosion, and stormwater treatment costs. In HRM, it is estimated that street trees provide about $2.1 million in stormwater reduction services annually.
The HRM Urban Forestry staff takes pride in being one of the leading urban forestry departments in Canada and plans to continue being a leader well into the future.
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.
Urban Forestry in the Future
By Len Phillips
If not already, in the very near future you may be driving down the street in a hybrid or electric vehicle. My personal vehicle is a hybrid and my wife has one as well. Filling up the gas tank once a month instead of every week, is a real treat. In a few years it will be an autonomous (self-driving) vehicle. The vehicle will be operated by artificial intelligence (AI).
Your city vehicle may soon be operated by AI as well. Urban AI is already being implemented to improve our cities in areas as diverse as autonomous vehicles, tree site selection, virtual planning, and augmented reality. As an arborist, you must accept this change and become aware of the impact that AI will have on the trees that line our city streets.
AI will be used to process information gathered from the sensors in self-driving trucks and cars, and this information will be shared with other vehicles by an interconnected network. These vehicles can see through adverse weather conditions like fog and snow to detect and avoid pedestrians and other vehicles in the road.
Eventually users will be able to hail a vehicle whenever they need one, using an Uber-type service. This advancement in urban navigation will result in less congestion in our cities, not to mention more fuel efficiency, thereby slowing the advance of climate change. It will also be possible to design safer shared surfaces where vehicles and pedestrians can coexist without incident. Autonomous vehicles are likely to amplify the current trend of reducing vehicle ownership in our cities. With autonomous vehicles being an Uber-type service, the car will be used by a dozen people during the day, none of whom would “own” the car. The cars would all be parked in central lots and each parking space would be smaller because the vehicles would be the size of a compact car and the "driver" does not need to get out of the car. This will result in fewer local parking lots, and less need for on-street parking spaces. The vacant parking areas can be converted to space for growing trees, parklets, pocket parks, urban greenways, and other environmental opportunities. This will result in an overall reduction in the number of vehicles on our roads, resulting in narrower streets, and fewer lanes, which in turn provide wider spaces than the sidewalk for new trees. Wider spaces will permit larger-sized areas for tree installations.
Due to the reduced rate of climate change and the increased number of tree installations, the arborist in the future will be able to install trees that will survive and thrive for the next 30 to 80 years, instead of the current future of a 10 to 20-year life span. This effort will go a long way toward dealing with climate change.
Perhaps one of the more obvious ways in which AI can impact the city is through quick and smart analysis of traffic data to enable energy efficiencies. For example, one firm is using AI to develop more sustainable traffic management through better, and automatic traffic light sequencing. Other firms have gotten together to develop an innovative intelligent LED streetlight control system that will use both real-time data gathered from sensors within the light fixtures, as well as external sources such as news and weather to intelligently adjust lighting levels as needed.
Automated Planning
Another benefit of AI is its ability to process large amounts of data quickly and efficiently. For example, advanced computer simulations can better predict the best location for future tree planting sites and the risk from urban storms and flooding. AI allows designers, policy makers, and politicians to gather data about public realm usage to make better decisions regarding resource allocation, future development, spatial planning, and locations for public shade trees.
Local government control over private tree planting and removals will be easily regulated very soon, thanks to the advent of AI. Updated aerial photography and drone photos will illustrate the gains or loss of canopy. This will be accomplished by using AI to determine the functional value of trees and forests. Associated private industries that inherit the urban forest will be using AI to provide a more scientific approach and regulation framework for the installation, maintenance, and management of the urban forest.
Predict and Mitigate Urban Decay
The Massachusetts Institute of Technology and Harvard University have developed an AI system that is able to run virtual computer simulations of urban decay in American cities. This information will help prevent conflicts, crime, and anti-social behavior. An AI system is able to predict which urban environments would fare better in the future, and which would be subject to decline. Interestingly, the research has already identified the neighborhoods with residents who have higher levels of education, streets that are lined with large shade trees, and access to business districts, as better predictors of neighborhood success than income or house prices.
Reduce Working Time
AI will have an impact upon how people will live and use the city. Some experts predict that AI may allow for greater automation of tasks, thus reducing the number of hours humans need to spend at work. This reduction in work time will result in an increase in leisure time which will result in a reduced demand for office space in the city and an increase in the demand for leisure facilities including parks and urban green spaces.
Smart City Solutions
Many municipalities are starting to adopt the concepts of “Smart City” in their governance. This involves data gathering and processing to assist in improving cities and making efficiencies through experimentation and innovation. The results will lead to changes that reduce crime, congestion, fewer road accidents, and more trees.
City councils are beginning to adopt an asset register accounting system, detailing the value of assets like roads, parks, street furniture, and more cities are including street trees as quantifiable assets. The larger the tree grows, the more assets the city can declare and the better a city can become, financially. (More on this subject in the next Online Seminar.)
Applications to Urban Forestry
AI is a leap into the future and it is a leap that municipal arborists should be aware of and accept, so we can make appropriate plans for future tree installations. If the future is going to reduce our use of gasoline powered vehicles and equipment with less pollution and lessening of global warming, then we will be able to install a wider variety of trees in our cities and create better municipal street landscapes with the more beautiful but tender trees that cannot be used with the looming threat of global warming or major storms.
AI will also have an impact on our selection of tree management equipment, better vehicles, smarter tools, and better mapping of our municipal street tree inventories. Forward thinking arborists should keep their eyes open for all the new trends that are expected to be appearing in the future, especially those that are based on using artificial intelligence.
Municipal arborists are members of a municipal government and are usually required to attend meetings with all city department heads. When a budget item makes an impact on one department, it impacts all departments. When artificial intelligence makes an impact on one department, it impacts all departments.
AI is a trend that is coming and cannot be ignored. It will be influencing many decisions we will all be making for Generation A (for Autonomous) in the care of our future cities and our urban trees.
Source
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.
By Len Phillips
If not already, in the very near future you may be driving down the street in a hybrid or electric vehicle. My personal vehicle is a hybrid and my wife has one as well. Filling up the gas tank once a month instead of every week, is a real treat. In a few years it will be an autonomous (self-driving) vehicle. The vehicle will be operated by artificial intelligence (AI).
Your city vehicle may soon be operated by AI as well. Urban AI is already being implemented to improve our cities in areas as diverse as autonomous vehicles, tree site selection, virtual planning, and augmented reality. As an arborist, you must accept this change and become aware of the impact that AI will have on the trees that line our city streets.
AI will be used to process information gathered from the sensors in self-driving trucks and cars, and this information will be shared with other vehicles by an interconnected network. These vehicles can see through adverse weather conditions like fog and snow to detect and avoid pedestrians and other vehicles in the road.
Eventually users will be able to hail a vehicle whenever they need one, using an Uber-type service. This advancement in urban navigation will result in less congestion in our cities, not to mention more fuel efficiency, thereby slowing the advance of climate change. It will also be possible to design safer shared surfaces where vehicles and pedestrians can coexist without incident. Autonomous vehicles are likely to amplify the current trend of reducing vehicle ownership in our cities. With autonomous vehicles being an Uber-type service, the car will be used by a dozen people during the day, none of whom would “own” the car. The cars would all be parked in central lots and each parking space would be smaller because the vehicles would be the size of a compact car and the "driver" does not need to get out of the car. This will result in fewer local parking lots, and less need for on-street parking spaces. The vacant parking areas can be converted to space for growing trees, parklets, pocket parks, urban greenways, and other environmental opportunities. This will result in an overall reduction in the number of vehicles on our roads, resulting in narrower streets, and fewer lanes, which in turn provide wider spaces than the sidewalk for new trees. Wider spaces will permit larger-sized areas for tree installations.
Due to the reduced rate of climate change and the increased number of tree installations, the arborist in the future will be able to install trees that will survive and thrive for the next 30 to 80 years, instead of the current future of a 10 to 20-year life span. This effort will go a long way toward dealing with climate change.
Perhaps one of the more obvious ways in which AI can impact the city is through quick and smart analysis of traffic data to enable energy efficiencies. For example, one firm is using AI to develop more sustainable traffic management through better, and automatic traffic light sequencing. Other firms have gotten together to develop an innovative intelligent LED streetlight control system that will use both real-time data gathered from sensors within the light fixtures, as well as external sources such as news and weather to intelligently adjust lighting levels as needed.
Automated Planning
Another benefit of AI is its ability to process large amounts of data quickly and efficiently. For example, advanced computer simulations can better predict the best location for future tree planting sites and the risk from urban storms and flooding. AI allows designers, policy makers, and politicians to gather data about public realm usage to make better decisions regarding resource allocation, future development, spatial planning, and locations for public shade trees.
Local government control over private tree planting and removals will be easily regulated very soon, thanks to the advent of AI. Updated aerial photography and drone photos will illustrate the gains or loss of canopy. This will be accomplished by using AI to determine the functional value of trees and forests. Associated private industries that inherit the urban forest will be using AI to provide a more scientific approach and regulation framework for the installation, maintenance, and management of the urban forest.
Predict and Mitigate Urban Decay
The Massachusetts Institute of Technology and Harvard University have developed an AI system that is able to run virtual computer simulations of urban decay in American cities. This information will help prevent conflicts, crime, and anti-social behavior. An AI system is able to predict which urban environments would fare better in the future, and which would be subject to decline. Interestingly, the research has already identified the neighborhoods with residents who have higher levels of education, streets that are lined with large shade trees, and access to business districts, as better predictors of neighborhood success than income or house prices.
Reduce Working Time
AI will have an impact upon how people will live and use the city. Some experts predict that AI may allow for greater automation of tasks, thus reducing the number of hours humans need to spend at work. This reduction in work time will result in an increase in leisure time which will result in a reduced demand for office space in the city and an increase in the demand for leisure facilities including parks and urban green spaces.
Smart City Solutions
Many municipalities are starting to adopt the concepts of “Smart City” in their governance. This involves data gathering and processing to assist in improving cities and making efficiencies through experimentation and innovation. The results will lead to changes that reduce crime, congestion, fewer road accidents, and more trees.
City councils are beginning to adopt an asset register accounting system, detailing the value of assets like roads, parks, street furniture, and more cities are including street trees as quantifiable assets. The larger the tree grows, the more assets the city can declare and the better a city can become, financially. (More on this subject in the next Online Seminar.)
Applications to Urban Forestry
AI is a leap into the future and it is a leap that municipal arborists should be aware of and accept, so we can make appropriate plans for future tree installations. If the future is going to reduce our use of gasoline powered vehicles and equipment with less pollution and lessening of global warming, then we will be able to install a wider variety of trees in our cities and create better municipal street landscapes with the more beautiful but tender trees that cannot be used with the looming threat of global warming or major storms.
AI will also have an impact on our selection of tree management equipment, better vehicles, smarter tools, and better mapping of our municipal street tree inventories. Forward thinking arborists should keep their eyes open for all the new trends that are expected to be appearing in the future, especially those that are based on using artificial intelligence.
Municipal arborists are members of a municipal government and are usually required to attend meetings with all city department heads. When a budget item makes an impact on one department, it impacts all departments. When artificial intelligence makes an impact on one department, it impacts all departments.
AI is a trend that is coming and cannot be ignored. It will be influencing many decisions we will all be making for Generation A (for Autonomous) in the care of our future cities and our urban trees.
Source
- Daniel, Matthew, “Urban Forestry Future Challenges” LinkedIn discussion group 202020, 2018.
- “Ways AI is Shaping the Future”, Land8, June 27, 2018.
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.
Outstanding Inventors of Trees
Keith Warren
Edited by Len Phillips
When it comes to inventing new trees, Keith Warren has a very impressive success rate. The Seattle native earned an English degree from Willamette University where he discovered his love for biology. From there he attended the University of Washington and received a degree in botany. After graduation, his search for work in the nursery business led him to apply for a job at J. Frank Schmidt & Son Co. a shade and flowering tree nursery in Oregon.
Keith spent the first few years as Schmidt’s farm manager at the Sunset Farm in Canby growing hundreds of thousands of shade trees. Next, he served as the nursery’s horticulturist, where he created and improved production techniques. This job morphed into plant research and development, where, as Director of Product Development, he trialed, evaluated and guided 88 new tree cultivars to commercial introduction. Thirty-eight of those 88 trademarked or patented trees arose from his personal breeding and selection work, with additional trees still in the production pipeline.
Keith's main goal was to find trees that solve a problem, which is in alignment with the nursery’s mission to develop and introduce improved tree cultivars for urban and landscape use. He and his product development team placed special emphasis on developing tough, adaptable and long-lived tree cultivars that will survive and thrive in urban settings where many other trees may fail. Many of his plant developments came from special seed source collections, while some were from hybridizing or selective breeding.
While at the helm of product development, Keith was tasked with analyzing sales history and market trends to better forecast the market’s needs, and to determine the nursery’s product mix. He honed those skills through constant communication with people throughout all facets of the industry. This is something he learned during his early years with the company, when his attendance at events such as METRIA (Metropolitan Tree Improvement Alliance) gatherings connected him to a network of tree breeders and scientists, urban foresters and other specifiers.
For more than 40 years, Keith walked the fields of the Schmidt nursery. A lot of what he did in terms of tree selection came from knowing the market well and knowing what the market needed. And you can only know that if you’re constantly talking to customers and municipalities, researchers, landscape architects, arborists, and many others in the industry.
Keith originated the tree form illustrations for which the Schmidt catalogs are well-known. He began creating the pen and ink drawings of the trees early in his career to help customers understand each tree's unique characteristics. The drawings help people get a better feel of the mature structure of the tree, how big the limbs are, or how close it may get when planted next to a building, for instance. It helps people know what to expect when that tree matures.
Of all the tree selections in his portfolio, Keith acknowledges that Redpointe® Maple (Acer rubrum ‘Frank Jr.’) has made the greatest impact in the marketplace. Introduced in 2006, 17 years after a special collection of seed was sown, it has become a top-seller.
“It’s our #1 selling tree,” he says. “Thanks to its strong central leader and branch structure, symmetrical growth habit and adaptability to varied growing conditions across the continent, it has been embraced by growers and specifiers and is widely planted.” Keith indicated that many of the faster-growing Red and Freeman maples have a weak branch structure and problems with splitting. Thanks to his rigorous selection criteria, Redpointe® does not have these structural problems.
Redpointe® also possesses good resistance to spider mites and demonstrates unusually high resistance to chlorosis in high pH soils. This opened up a large market for a tree in areas where most red maples do not grow well.
Some other significant trees developed by Keith include:
For more information on these trees and other JFS introductions visit: Introductions
Keith was honored in 2015 by the Oregon Association of Nurseries with the OAN Outstanding Service Award for his 40+ years of service to J. Frank Schmidt & Son Co. and to the entire industry. In 2015, Keith officially retired from JFS. However, he still has trees that are moving toward introduction in the coming years and he still has a spot at the office to call his own. He now has a little more time for things like hiking the mountains and forests of the Pacific Northwest, skiing and fly fishing. He has spent the past three years writing and photographing for a book co-authored with Dr. Michael Dirr. Published by Timber Press, “The Tree Book, Superior Selections for Landscapes, Streetscapes and Gardens”. The book is packed with up-to-date listings, descriptions, and photographs of contemporary and new tree cultivars.
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.
Keith Warren
Edited by Len Phillips
When it comes to inventing new trees, Keith Warren has a very impressive success rate. The Seattle native earned an English degree from Willamette University where he discovered his love for biology. From there he attended the University of Washington and received a degree in botany. After graduation, his search for work in the nursery business led him to apply for a job at J. Frank Schmidt & Son Co. a shade and flowering tree nursery in Oregon.
Keith spent the first few years as Schmidt’s farm manager at the Sunset Farm in Canby growing hundreds of thousands of shade trees. Next, he served as the nursery’s horticulturist, where he created and improved production techniques. This job morphed into plant research and development, where, as Director of Product Development, he trialed, evaluated and guided 88 new tree cultivars to commercial introduction. Thirty-eight of those 88 trademarked or patented trees arose from his personal breeding and selection work, with additional trees still in the production pipeline.
Keith's main goal was to find trees that solve a problem, which is in alignment with the nursery’s mission to develop and introduce improved tree cultivars for urban and landscape use. He and his product development team placed special emphasis on developing tough, adaptable and long-lived tree cultivars that will survive and thrive in urban settings where many other trees may fail. Many of his plant developments came from special seed source collections, while some were from hybridizing or selective breeding.
While at the helm of product development, Keith was tasked with analyzing sales history and market trends to better forecast the market’s needs, and to determine the nursery’s product mix. He honed those skills through constant communication with people throughout all facets of the industry. This is something he learned during his early years with the company, when his attendance at events such as METRIA (Metropolitan Tree Improvement Alliance) gatherings connected him to a network of tree breeders and scientists, urban foresters and other specifiers.
For more than 40 years, Keith walked the fields of the Schmidt nursery. A lot of what he did in terms of tree selection came from knowing the market well and knowing what the market needed. And you can only know that if you’re constantly talking to customers and municipalities, researchers, landscape architects, arborists, and many others in the industry.
Keith originated the tree form illustrations for which the Schmidt catalogs are well-known. He began creating the pen and ink drawings of the trees early in his career to help customers understand each tree's unique characteristics. The drawings help people get a better feel of the mature structure of the tree, how big the limbs are, or how close it may get when planted next to a building, for instance. It helps people know what to expect when that tree matures.
Of all the tree selections in his portfolio, Keith acknowledges that Redpointe® Maple (Acer rubrum ‘Frank Jr.’) has made the greatest impact in the marketplace. Introduced in 2006, 17 years after a special collection of seed was sown, it has become a top-seller.
“It’s our #1 selling tree,” he says. “Thanks to its strong central leader and branch structure, symmetrical growth habit and adaptability to varied growing conditions across the continent, it has been embraced by growers and specifiers and is widely planted.” Keith indicated that many of the faster-growing Red and Freeman maples have a weak branch structure and problems with splitting. Thanks to his rigorous selection criteria, Redpointe® does not have these structural problems.
Redpointe® also possesses good resistance to spider mites and demonstrates unusually high resistance to chlorosis in high pH soils. This opened up a large market for a tree in areas where most red maples do not grow well.
Some other significant trees developed by Keith include:
- Armstrong Gold® Maple (Acer rubrum ‘JFS-KW78’)
- Ruby Sunset® Maple (Acer truncatum x A. platanoides JFS-KW249)
- Urban Sunset® Maple (Acer truncatum x A. platanoides JFS-KW187)
- Royal Raindrops® Crabapple (Malus JFS-KW5)
- Sparkling Sprite® Crabapple (Malus JFS-KW207)
- Ivory Spear™ Crabapple (Malus JFS-KW214MX)
- Firestarter® Tupelo (Nyssa sylvatica JFS-red PP26795)
- City Sprite® Zelkova (Zelkova serrata JFS-KW1 PP20996)
- Emerald City® Tulip Tree (Liriodendron tulipifera JFS-Oz)
- Keith hopes to soon select a double-flowering crabapple with the same disease resistance as his earlier selection, Sparkling Sprite.
For more information on these trees and other JFS introductions visit: Introductions
Keith was honored in 2015 by the Oregon Association of Nurseries with the OAN Outstanding Service Award for his 40+ years of service to J. Frank Schmidt & Son Co. and to the entire industry. In 2015, Keith officially retired from JFS. However, he still has trees that are moving toward introduction in the coming years and he still has a spot at the office to call his own. He now has a little more time for things like hiking the mountains and forests of the Pacific Northwest, skiing and fly fishing. He has spent the past three years writing and photographing for a book co-authored with Dr. Michael Dirr. Published by Timber Press, “The Tree Book, Superior Selections for Landscapes, Streetscapes and Gardens”. The book is packed with up-to-date listings, descriptions, and photographs of contemporary and new tree cultivars.
Sources
- Special thanks to Nancy Buley, Public Relations and Communications Manager at J. Frank Schmidt & Son.
- J. Frank Schmidt & Son Co., website, 2018.
- OAN Digger archives
- Rodda, Kelli, “An Artist's Touch”, Nursery Management, March 2016.
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 Seminar #81
By Len Phillips
City Sprite Zelkova is ideal for narrow street use. The tightly upright branches allow good vehicle and pedestrian clearance beneath the delicate green canopy. The tidy growth habit promises this to be a low maintenance city tree.
Trade Name: City Sprite Zelkova
Botanical Name: Zelkova serrata JS-KW1 PP 20996
Parentage: Selection from Z. serrata growing in Japan
Family: Ulmaceae
Height: 20' - 30'
Spread: 15' - 20'
Form: Compact oval to vase
Flower: Inconspicuous
Fruit: Inconspicuous if any
Summer Foliage: Bright green, fine textured, short internodes
Autumn Foliage: Yellow
Winter Color: Bark provides winter interest
Bark: Straight trunk, smooth and gray, flaky with orange patches on older trunks
Habitat: Native to Eastern Asia
Culture: Prefers a medium loam, moist, well drained, deep soil, adapts to all pH, somewhat sensitive to soil conditions, likes full sun, tolerates pollution, drought, wind, and shade
Hardiness Zone: 5 – 9
Growth Rate: Vigorous, 30' in 25 years
Pest Resistance: Resistant to Dutch Elm Disease and Elm beetles as well as the Japanese beetle
Storm Resistance: Good
Salt Resistance: Excellent
Planting: Transplants easily bare root, B&B, and by container, plant in spring only, excellent choice for a CU-Structural Soil project
Pruning: Thin out branches when young to encourage healthier branch unions and perfectly spaced branches; prune young trees in autumn
Propagating: Budded onto species understock
Design Uses: Medium texture, good for homes, streets, parks, and commercial landscapes
Companions: Mix in with low growing perennials that will not hide the beautiful bark
Other Comments: Short trunk, ideal for street tree use, this is a Keith Warren introduction
Available from: Many large nurseries
Photo
Sources: This information has been gathered from personal observations of the author, living in Massachusetts, Zone 6 and information provided by our sponsor J. Frank Schmidt & Son.
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.
By Len Phillips
City Sprite Zelkova is ideal for narrow street use. The tightly upright branches allow good vehicle and pedestrian clearance beneath the delicate green canopy. The tidy growth habit promises this to be a low maintenance city tree.
Trade Name: City Sprite Zelkova
Botanical Name: Zelkova serrata JS-KW1 PP 20996
Parentage: Selection from Z. serrata growing in Japan
Family: Ulmaceae
Height: 20' - 30'
Spread: 15' - 20'
Form: Compact oval to vase
Flower: Inconspicuous
Fruit: Inconspicuous if any
Summer Foliage: Bright green, fine textured, short internodes
Autumn Foliage: Yellow
Winter Color: Bark provides winter interest
Bark: Straight trunk, smooth and gray, flaky with orange patches on older trunks
Habitat: Native to Eastern Asia
Culture: Prefers a medium loam, moist, well drained, deep soil, adapts to all pH, somewhat sensitive to soil conditions, likes full sun, tolerates pollution, drought, wind, and shade
Hardiness Zone: 5 – 9
Growth Rate: Vigorous, 30' in 25 years
Pest Resistance: Resistant to Dutch Elm Disease and Elm beetles as well as the Japanese beetle
Storm Resistance: Good
Salt Resistance: Excellent
Planting: Transplants easily bare root, B&B, and by container, plant in spring only, excellent choice for a CU-Structural Soil project
Pruning: Thin out branches when young to encourage healthier branch unions and perfectly spaced branches; prune young trees in autumn
Propagating: Budded onto species understock
Design Uses: Medium texture, good for homes, streets, parks, and commercial landscapes
Companions: Mix in with low growing perennials that will not hide the beautiful bark
Other Comments: Short trunk, ideal for street tree use, this is a Keith Warren introduction
Available from: Many large nurseries
Photo
Sources: This information has been gathered from personal observations of the author, living in Massachusetts, Zone 6 and information provided by our sponsor J. Frank Schmidt & Son.
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.
Can Forests Deal with Climate Change?
Edited by Len Phillips
After very cold weather during the 2017–2018 winter, warming temperatures might not sound bad. But for forest trees and trees in urban neighborhoods, climate change is likely to cause a variety of problems with tree health. Since 1880, average global temperatures have risen approximately 1.5°F (0.8°C) and depending on greenhouse gas emission levels, we could see another 1°F (0.6°C) in the next 20 years and 8°F (4.4°C) by 2100. In the near future, summer temperatures in certain cities are predicted to be 120°F (50°C).
Migration Difficulties
Plants and trees have responded to rising temperatures by greening up earlier in the spring, and plants growing in the wild are slowly shifting their distribution northward and to higher and cooler elevations. Global warming projections suggest that plants will need to migrate northward 2-3 miles (3-5 km) every year just to keep up with warming temperatures. This rate is much faster than the natural ability of trees to migrate. Some short-lived plant species might be able to adapt to changing climate over several generations. Longer-lived trees are unlikely to have enough generations to adapt to the rapidly warming climate. Without human assistance, most forests may be unable to keep up with global warming.
As a consequence, increasing rates of tree mortality are being observed globally. Tree seedlings are having a harder time germinating and becoming established at the warmer temperatures where the mother tree is living. On the other hand, tree seedlings are having an easier time in cooler locations that were previously too cold to support tree growth. This means a shift in the tree's range. For example, surveys showed an expansion of northern hardwoods seedlings such as pine, maple, and birch growing at a higher and cooler elevations.
Forest Management
Warming conditions will also affect the health of urban trees. Urban forest managers may be able to provide some relief to existing tree populations by applying best management practices that help alleviate some of the environmental stresses as well as by replanting with more heat tolerant trees.
Strategically applying mulch and more frequent watering can protect an urban tree from soil compaction, injury, and drought. Watering may ease the stress of global warming. Foregoing fertilization to avoid pushing unnecessary growth will help survival during a difficult growing season.
Projections suggest that many important species, such as sugar maple (Acer saccharum) and balsam fir (Abies balsamea), are likely to lose a significant amount of suitable habitat over the next 100 years and will be replaced with the better suited oak-hickory hardwood and oak-pine mixed forests.
Replanting the Forest
Some of the tree species predicted to lose ground as a result of global warming include shagbark hickory (Carya ovata) and American basswood (Tilia americana L.). Urban foresters and arborists should think twice before selecting and planting these trees unless they are being installed in a colder than normal location.
In the urban forest, experts recommend planting resilient species such as Kentucky coffee-tree (Gymnocladus dioicus), London plane-tree (Platanus x acerifolia), hackberry (Celtis occidentalis), honey-locust (Gleditsia triacanthos), swamp white oak (Quercus bicolor), and Freeman maple (Acer x freemanii), all of which have been successfully installed for many years in the northern areas of the United States by arborists and urban foresters. Keep the diversification formula in mind when using these trees. It is also recommended to incorporate a diverse array of species that are not only indigenous to more southerly climates, but are tolerant of urban growing conditions, such as bald-cypress (Taxodium distichum), sweet-gum (Liquidambar styraciflua), and several common southern oak trees, like turkey oak (Quercus laevis) and willow oak (Quercus phellos).
Also, keep in mind that nurseries are making selections of heat tolerant trees that should be used for the long term. Many of these trees have become selected as new cultivars.
Persistent Species
Species most likely to persist will be the ones we choose to plant outside of their historic range. However, there are various challenges to this strategy. A lack of specific implementation instructions, uncertainties about future climate conditions, existing policies, and lack of nursery stock can all hinder efforts to assist tree migration. Keep in mind that a selection that will tolerate future heat, must also be able to tolerate cold winters and winter storms that are associated with global warming.
The greatest concern associated with assisted migration is the accidental introduction of species that go on to become invasive and problematic to surrounding ecosystems and economies. Generally, trees that could not easily arrive in your region without human assistance are more likely to become invasive than those that evolved within the current forest.
Pest Management
Planting trees from international sources not only increases the likelihood of introducing a novel invasive plant, international live plant imports are also the primary source of forest insect pests. An estimated 12 percent of live plant imports are contaminated by some form of forest insect, mite, or pathogen. Moreover, warmer temperatures with global warming can sustain higher populations and diversity of forest pests, which tend to be less cold tolerant. Pest management protocols for urban trees, including vigilant monitoring, confirmation of diagnosis, and appropriate remedial actions should be implemented where appropriate.
In addition to shifting plant and pest distributions, global warming is also lengthening the growing season. For example, based on historical herbarium records, flowering times have advanced by an average of 8 days between 1900-2000. While it is nice to see those spring blooms a little earlier, one consequence is that species are being increasingly damaged by frost. Insect pollinators are also out-of-sync with normal bloom times. Additionally, early warming may harm interactions between trees and animals by creating mismatches in the timing of pollination and seed dispersal. Although longer growing seasons and higher atmospheric carbon dioxide concentrations suggest an increase in tree productivity, increased climate stress, pests, and disease could instead lead to an overall decrease in tree productivity.
Future Forest Change
To understand future forest change, ongoing inventorying, monitoring, and analysis are necessary. Urban forests provide a myriad of ecosystem services, and maintaining their resilience under global warming to preserve these benefits will require significant management efforts. Preserving warmer climate tolerant
tree species toward the southern edges of their range means mitigating drought and pest stress. Meanwhile, assisting the migration of more southerly North American tree species into northern locations is one important step toward developing climate smart urban forests.
Source
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
After very cold weather during the 2017–2018 winter, warming temperatures might not sound bad. But for forest trees and trees in urban neighborhoods, climate change is likely to cause a variety of problems with tree health. Since 1880, average global temperatures have risen approximately 1.5°F (0.8°C) and depending on greenhouse gas emission levels, we could see another 1°F (0.6°C) in the next 20 years and 8°F (4.4°C) by 2100. In the near future, summer temperatures in certain cities are predicted to be 120°F (50°C).
Migration Difficulties
Plants and trees have responded to rising temperatures by greening up earlier in the spring, and plants growing in the wild are slowly shifting their distribution northward and to higher and cooler elevations. Global warming projections suggest that plants will need to migrate northward 2-3 miles (3-5 km) every year just to keep up with warming temperatures. This rate is much faster than the natural ability of trees to migrate. Some short-lived plant species might be able to adapt to changing climate over several generations. Longer-lived trees are unlikely to have enough generations to adapt to the rapidly warming climate. Without human assistance, most forests may be unable to keep up with global warming.
As a consequence, increasing rates of tree mortality are being observed globally. Tree seedlings are having a harder time germinating and becoming established at the warmer temperatures where the mother tree is living. On the other hand, tree seedlings are having an easier time in cooler locations that were previously too cold to support tree growth. This means a shift in the tree's range. For example, surveys showed an expansion of northern hardwoods seedlings such as pine, maple, and birch growing at a higher and cooler elevations.
Forest Management
Warming conditions will also affect the health of urban trees. Urban forest managers may be able to provide some relief to existing tree populations by applying best management practices that help alleviate some of the environmental stresses as well as by replanting with more heat tolerant trees.
Strategically applying mulch and more frequent watering can protect an urban tree from soil compaction, injury, and drought. Watering may ease the stress of global warming. Foregoing fertilization to avoid pushing unnecessary growth will help survival during a difficult growing season.
Projections suggest that many important species, such as sugar maple (Acer saccharum) and balsam fir (Abies balsamea), are likely to lose a significant amount of suitable habitat over the next 100 years and will be replaced with the better suited oak-hickory hardwood and oak-pine mixed forests.
Replanting the Forest
Some of the tree species predicted to lose ground as a result of global warming include shagbark hickory (Carya ovata) and American basswood (Tilia americana L.). Urban foresters and arborists should think twice before selecting and planting these trees unless they are being installed in a colder than normal location.
In the urban forest, experts recommend planting resilient species such as Kentucky coffee-tree (Gymnocladus dioicus), London plane-tree (Platanus x acerifolia), hackberry (Celtis occidentalis), honey-locust (Gleditsia triacanthos), swamp white oak (Quercus bicolor), and Freeman maple (Acer x freemanii), all of which have been successfully installed for many years in the northern areas of the United States by arborists and urban foresters. Keep the diversification formula in mind when using these trees. It is also recommended to incorporate a diverse array of species that are not only indigenous to more southerly climates, but are tolerant of urban growing conditions, such as bald-cypress (Taxodium distichum), sweet-gum (Liquidambar styraciflua), and several common southern oak trees, like turkey oak (Quercus laevis) and willow oak (Quercus phellos).
Also, keep in mind that nurseries are making selections of heat tolerant trees that should be used for the long term. Many of these trees have become selected as new cultivars.
Persistent Species
Species most likely to persist will be the ones we choose to plant outside of their historic range. However, there are various challenges to this strategy. A lack of specific implementation instructions, uncertainties about future climate conditions, existing policies, and lack of nursery stock can all hinder efforts to assist tree migration. Keep in mind that a selection that will tolerate future heat, must also be able to tolerate cold winters and winter storms that are associated with global warming.
The greatest concern associated with assisted migration is the accidental introduction of species that go on to become invasive and problematic to surrounding ecosystems and economies. Generally, trees that could not easily arrive in your region without human assistance are more likely to become invasive than those that evolved within the current forest.
Pest Management
Planting trees from international sources not only increases the likelihood of introducing a novel invasive plant, international live plant imports are also the primary source of forest insect pests. An estimated 12 percent of live plant imports are contaminated by some form of forest insect, mite, or pathogen. Moreover, warmer temperatures with global warming can sustain higher populations and diversity of forest pests, which tend to be less cold tolerant. Pest management protocols for urban trees, including vigilant monitoring, confirmation of diagnosis, and appropriate remedial actions should be implemented where appropriate.
In addition to shifting plant and pest distributions, global warming is also lengthening the growing season. For example, based on historical herbarium records, flowering times have advanced by an average of 8 days between 1900-2000. While it is nice to see those spring blooms a little earlier, one consequence is that species are being increasingly damaged by frost. Insect pollinators are also out-of-sync with normal bloom times. Additionally, early warming may harm interactions between trees and animals by creating mismatches in the timing of pollination and seed dispersal. Although longer growing seasons and higher atmospheric carbon dioxide concentrations suggest an increase in tree productivity, increased climate stress, pests, and disease could instead lead to an overall decrease in tree productivity.
Future Forest Change
To understand future forest change, ongoing inventorying, monitoring, and analysis are necessary. Urban forests provide a myriad of ecosystem services, and maintaining their resilience under global warming to preserve these benefits will require significant management efforts. Preserving warmer climate tolerant
tree species toward the southern edges of their range means mitigating drought and pest stress. Meanwhile, assisting the migration of more southerly North American tree species into northern locations is one important step toward developing climate smart urban forests.
Source
- “Can Community Forests in the Northeast U.S. Keep Pace with a Changing Climate?” By Ashley McElhinney, Bethany Bradley, and Richard W. Harper
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.
The Affect Trees Have on the Human Brain
Edited by Len Phillips
We know trees affect the human brain because we feel good after a run along a forest path. However, only recently have we starting to understand the how and the why. Our immediate environment can prompt both positive relaxation and negative global warming on our bodies and brains. It is also becoming evident that trees can exert a strong influence on our behavior. This is especially important in cities, where mental health problems caused by over-stimulation, isolation, and loneliness are particularly high. To alleviate some of these city stressors, we appreciate the benefits of trees by taking a walk in the woods or simply standing underneath a large city tree. Many factors contribute to positive mental health and wellness, including biological factors, experiences, and lifestyle. However, the built environment also plays a critical role in the human mental health and this is not necessarily good.
Mental Health in the City
While mental health and happiness can be difficult to measure, cities are associated with higher rates of mental health problems compared to rural and heavily wooded residential areas. City dwellers have an almost 40 percent higher risk of depression, over 20 percent more anxiety, and 50 percent have a risk of schizophrenia, in addition to loneliness, isolation, and stress from crime, gridlock traffic, and work demands.
Positive Mental Health
Good mental health is critical for both individual well-being and overall human health, but it is not often found in people living in the city. Fortunately, trees have the potential to help support better mental health. Conditions in the city such as pollution, noise, crime, and over-stimulation can be reduced with trees. Good mental health can improve a person's enjoyment, coping skills, and relationships, as well as educational achievement, housing, employment, and economic potential. Good mental health helps reduce physical health problems, ease healthcare and social care costs, build social happiness, and decrease suicides and major illness.
Solution
A set of recommendations has just been released which encourages access to trees, green spaces, and nature. Increasing community walk-ability and bike-ability, as well as providing good public transit, ensures opportunities for people to be active, which is also linked to improved mental health. Dedicated spaces for sports fields and tennis courts provide active space, as do walking loops in parks. Collectively, green space and active space should be weaved throughout the urban fabric. These recommendations have been shown to improve mental health, reduce depression, and improve cognitive functioning. The experience of nature is an antidote to the stress of urban living. Promoting the installation of street trees, appreciating views of nature, and participating in community gardens are all ways to reduce stress.
Creating social places that encourage interaction is one of the most important opportunities for promoting good mental health. Designing cities that enable human connection helps combat loneliness and feelings of isolation. Social interaction builds self-confidence and fosters a sense of community and belonging. Mixed-use development, which blends shops, offices, trees, open spaces, and residential spaces into a single neighborhood, is one design approach that sparks interaction among individuals. Design elements as simple as sidewalks and benches promote conversations, and the creation of open spaces allows for informal meeting spaces for groups. The perceived safety and security of a space is also a component of how people feel.
Positive Examples
Some architects and urban designers have already put this research into action. For example, the Trust for Public Land, which recognizes the importance of green space to promote mental health, has several urban greening initiatives underway in Chicago and Los Angeles,.
In Chicago’s Northwest side, one recent project transformed nearly three miles of unused rail line into an elevated trail. The 606 integrates the community with green space and provides an alternative, uninterrupted commute through the city. This 2.7-mile (4 km) trail acts as a community connector between four neighborhoods and six ground-level parks. This alternative transportation corridor provides commuters with a less hectic travel and gives low-income neighborhoods spaces to connect to nature and thrive as a community.
In South Los Angeles, a 16-square mile (40 sq. km) area of concrete alleys are being converted into safe, green, community spaces. The Green Alley Master Plan creates a network that improves community walk-ability and green space to serve one of the most under-served communities in the region. Both projects highlight the potential that trees have to alleviate city stressors and create livable cities.
While more research is needed, there is already clear evidence that proper planting of trees and design can promote good mental health. Understanding the effects of trees is the first step in helping to create saner, safer, happier 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, 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
We know trees affect the human brain because we feel good after a run along a forest path. However, only recently have we starting to understand the how and the why. Our immediate environment can prompt both positive relaxation and negative global warming on our bodies and brains. It is also becoming evident that trees can exert a strong influence on our behavior. This is especially important in cities, where mental health problems caused by over-stimulation, isolation, and loneliness are particularly high. To alleviate some of these city stressors, we appreciate the benefits of trees by taking a walk in the woods or simply standing underneath a large city tree. Many factors contribute to positive mental health and wellness, including biological factors, experiences, and lifestyle. However, the built environment also plays a critical role in the human mental health and this is not necessarily good.
Mental Health in the City
While mental health and happiness can be difficult to measure, cities are associated with higher rates of mental health problems compared to rural and heavily wooded residential areas. City dwellers have an almost 40 percent higher risk of depression, over 20 percent more anxiety, and 50 percent have a risk of schizophrenia, in addition to loneliness, isolation, and stress from crime, gridlock traffic, and work demands.
Positive Mental Health
Good mental health is critical for both individual well-being and overall human health, but it is not often found in people living in the city. Fortunately, trees have the potential to help support better mental health. Conditions in the city such as pollution, noise, crime, and over-stimulation can be reduced with trees. Good mental health can improve a person's enjoyment, coping skills, and relationships, as well as educational achievement, housing, employment, and economic potential. Good mental health helps reduce physical health problems, ease healthcare and social care costs, build social happiness, and decrease suicides and major illness.
Solution
A set of recommendations has just been released which encourages access to trees, green spaces, and nature. Increasing community walk-ability and bike-ability, as well as providing good public transit, ensures opportunities for people to be active, which is also linked to improved mental health. Dedicated spaces for sports fields and tennis courts provide active space, as do walking loops in parks. Collectively, green space and active space should be weaved throughout the urban fabric. These recommendations have been shown to improve mental health, reduce depression, and improve cognitive functioning. The experience of nature is an antidote to the stress of urban living. Promoting the installation of street trees, appreciating views of nature, and participating in community gardens are all ways to reduce stress.
Creating social places that encourage interaction is one of the most important opportunities for promoting good mental health. Designing cities that enable human connection helps combat loneliness and feelings of isolation. Social interaction builds self-confidence and fosters a sense of community and belonging. Mixed-use development, which blends shops, offices, trees, open spaces, and residential spaces into a single neighborhood, is one design approach that sparks interaction among individuals. Design elements as simple as sidewalks and benches promote conversations, and the creation of open spaces allows for informal meeting spaces for groups. The perceived safety and security of a space is also a component of how people feel.
Positive Examples
Some architects and urban designers have already put this research into action. For example, the Trust for Public Land, which recognizes the importance of green space to promote mental health, has several urban greening initiatives underway in Chicago and Los Angeles,.
In Chicago’s Northwest side, one recent project transformed nearly three miles of unused rail line into an elevated trail. The 606 integrates the community with green space and provides an alternative, uninterrupted commute through the city. This 2.7-mile (4 km) trail acts as a community connector between four neighborhoods and six ground-level parks. This alternative transportation corridor provides commuters with a less hectic travel and gives low-income neighborhoods spaces to connect to nature and thrive as a community.
In South Los Angeles, a 16-square mile (40 sq. km) area of concrete alleys are being converted into safe, green, community spaces. The Green Alley Master Plan creates a network that improves community walk-ability and green space to serve one of the most under-served communities in the region. Both projects highlight the potential that trees have to alleviate city stressors and create livable cities.
While more research is needed, there is already clear evidence that proper planting of trees and design can promote good mental health. Understanding the effects of trees is the first step in helping to create saner, safer, happier cities.
Sources
- Berg, Nancy, "Can your City Change your Mind”, Curbed, Nov 16, 2016.
- Goodyear, Sarah, "Green Spaces That Actually Calm the Mind and Body”, CityLab, June 26, 2013.
- Marino, Stephanie, “Trees Affect the Brain”, “Dirt”, 2018.
- Urban Forestry/Urban Greening Research, "Green Cities: Good Health", 2018.
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.
Successful Soil for Tree Growth
Edited By Len Phillips
The clearing of land in urban and suburban areas represents the extreme of soil and tree disturbance. Getting trees re-established is often a great challenge. During construction, the links between trees and soil microorganisms are broken. These linkages previously allowed trees to survive and thrive in natural environments for millions of years without the use of fertilizers, pesticides, and irrigation. Arborists are now gaining increased appreciation of the living soil and more frequently incorporating soil biology management into their practices.
This understanding of soil biology management is important because almost all of the world's tree species form a symbiotic arrangement with beneficial soil fungi called mycorrhizal fungi. The tree roots are colonized by soil fungi which attach to the roots and the fungi form a network that extends into the surrounding soil environment. Mycorrhizal fungi are the dominant microbes in undisturbed soils accounting for 60 to 80 percent of the microbial biomass. Mycorrhizae are fundamental to tree establishment, supplying much of the water and nutrients needed for tree survival and in exchange, receive essential sugars and other compounds supplied by the tree for mycorrhizae survival and growth. These fungi are also responsible for providing communication linkage between trees and also assisting trees with sharing essential compounds with other trees.
There are basically two broad groups of mycorrhizal fungi:
Ectomycorrhizae
Trees forming ectomycorrhizae include the vast majority of the tree species growing in the temperate and northern forests and 70 percent of the tree species growing in the tropics. Ectomycorrhizal fungi benefit most conifer species, such as pine, fir, spruce, and hemlock, and hardwoods such as oak, birch, beech, and madrone.
Arbuscular Mycorrhizae
Plants forming arbuscular mycorrhizae (also referred to as “AM”, “VAM“ and “endo mycorrhizae”) are commercially important horticultural and agricultural plants. Unlike the ectomycorrhizae, no external modification of the root accompanies arbuscular mycorrhizae. Arbuscular mycorrhizal fungi benefit ash, gum, maple and other trees as well as shrubs and ornamental plants.
There are few trees that don’t rely on any mycorrhizae in their natural environment, and they are the “weedy species” that grow very quickly following disturbance events and raise havoc with existing mycorrhizal fungi.
Mycorrhizal fungi increase the surface absorbing area of roots by ten to one thousand times, thereby greatly improving the ability of the trees to use soil resources and to communicate with other neighboring trees. They also form an intricate web that captures and assimilates nutrients in the soil. This means that mycorrhizal fungi increase a tree's nutrient uptake by increasing the absorbing surface area of roots. Mycorrhizal fungi release powerful chemicals into the soil that dissolve hard-to-capture nutrients, such as phosphorous, iron, and other “tightly bound” soil nutrients. This extraction process is particularly important in tree nutrition and explains why non-mycorrhizal trees require frequent fertilizer treatments to maintain their health.
Mycorrhizal fungi are involved with a wide variety of other activities that benefit tree establishment and growth. The same extensive network of fungal filaments important to nutrient uptake are also important in water uptake and storage. In soil conditions where there is no irrigation, trees with mycorrhizal fungal filaments attached to their roots are under far less drought stress compared to non-mycorrhizal trees. Suppression of diseases and pathogens are additional benefits for a mycorrhizal tree. Mycorrhizal fungi attack pathogen or disease organisms entering the root zone. For example, excretions of specific antibiotics produced by mycorrhizal fungi immobilize and kill disease organisms. These mycorrhizal fungi protect trees from Phytophthora, Fusarium, and Rhizoctonia diseases.
Mycorrhizal fungi also improve soil structure. Mycorrhizal filaments produce humic compounds and organic “glues” (extracellular polysaccharides) that bind soil particles into aggregates and improve soil porosity. Soil porosity and soil structure positively influence the growth of trees by promoting aeration, water movement into the soil, root growth, and root distribution.
Many practical benefits can be expected from using mycorrhizal fungi in common practices. These include improved survival, healthier growth; more rooting, profuse flowering, and increased fruiting. Benefits also include protection against disease; improved soil structure; and resistance to invasion by non-mycorrhizal or exotic tree species.
The root – mycorrhizal fungi relationship is the best understood subject in the field of soil biology. There are thousands of scientific studies on the subject. The earliest fossil record of the roots on land plants contain the almost identical arbuscular mycorrhizae to what is found today. Most scientists today believe the tree – mycorrhizal relationship allowed aquatic plants to make the transition to the relatively harsh terrestrial environment some 430 million years ago. In nature, mycorrhizae make tree growth possible, linking the roots of trees to the surrounding soil. In nature, neither can survive without the other.
Soils from natural and undisturbed areas generally contain robust and diverse populations of mycorrhizal fungi. Research shows that compaction, erosion, grading, topsoil removal, overgrazing, and the use of soil-less mixes in growing operations often eliminate the mycorrhizal fungi completely.
In a disturbed habitat, the return of mycorrhizae is dependent on the quality and proximity of undisturbed habitats containing suitable fungi. Many cases have been documented where soils in disturbed urban and suburban environments have not formed mycorrhizae even many years after planting and are surviving only through intensive care and maintenance.
Fertilizer alone cannot prevent root disease, improve soil structure, or promote beneficial microbes. Fertilizer alone can lead to other side effects, such as deterioration of water quality, soil structure, and excess soil salinity. The mycorrhizae improve feeder-root production, and better utilization of fertilizer.
Growing trees in a nursery and establishing trees on disturbed sites require an understanding of the many soil processes important in facilitating uptake, storage, and cycling of nutrients and water by tree species. In nature, these activities are largely performed by the microorganisms working hard below the soil surface in the living soil. In past decades, clearing of natural areas and disturbances in suburban and urban environments have substantially reduced microorganism populations. Because above ground and below ground tree/soil systems are tightly interdependent, such changes can result in poor tree survival and health.
Caution
What is clear is that on disturbed and stressful sites, inoculation of mycorrhizae is highly effective. The form and application of the mycorrhizal inoculum depends upon the needs of the applicator. Inoculum can be incorporated into the planting hole at the time of transplanting, watered into porous soils, mixed into soil-less mixes, or directly dipped onto bare roots using gels. Many arborists have had great success collecting their own fresh mycorrhizae. It can be found by digging around the roots of an established tree similar in species to the one being planted. During the digging process, scrape some of the soil off the roots of the trees and relocate that soil over the roots of the newly installed tree. The mycorrhizae on the established tree are found growing right against the roots of the established tree, in the rhizosphere.
Commercial mycorrhizal inoculum comes in granular forms, tablet forms, and powder forms. Purchasing mycorrhizae inoculum from specialty companies has mixed results. While most of the time, the inoculum is fresh and viable, it can also be old and have no viable fungi present in the package. Sometimes the product has dried out, been frozen, or exposed to high heat, all of which will kill the fungi. Because of all these potential problems, the buyer should require the fungi to be fresh and delivered as quickly as possible.
Sources
Amaranthus, Mike, “The Secret to Planting Success”, Mycorrhizal Applications Inc. 2014.
Thurman, Peter and Len Phillips, “Time to Break the Mold”, Pro Arb June 2018.
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 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
The clearing of land in urban and suburban areas represents the extreme of soil and tree disturbance. Getting trees re-established is often a great challenge. During construction, the links between trees and soil microorganisms are broken. These linkages previously allowed trees to survive and thrive in natural environments for millions of years without the use of fertilizers, pesticides, and irrigation. Arborists are now gaining increased appreciation of the living soil and more frequently incorporating soil biology management into their practices.
This understanding of soil biology management is important because almost all of the world's tree species form a symbiotic arrangement with beneficial soil fungi called mycorrhizal fungi. The tree roots are colonized by soil fungi which attach to the roots and the fungi form a network that extends into the surrounding soil environment. Mycorrhizal fungi are the dominant microbes in undisturbed soils accounting for 60 to 80 percent of the microbial biomass. Mycorrhizae are fundamental to tree establishment, supplying much of the water and nutrients needed for tree survival and in exchange, receive essential sugars and other compounds supplied by the tree for mycorrhizae survival and growth. These fungi are also responsible for providing communication linkage between trees and also assisting trees with sharing essential compounds with other trees.
There are basically two broad groups of mycorrhizal fungi:
- those forming ectomycorrhizae, so termed because they provide an external modification to the root,
- those termed arbuscular mycorrhizae (formerly termed endomycorrhizae), are internal and are formed within the root cells.
Ectomycorrhizae
Trees forming ectomycorrhizae include the vast majority of the tree species growing in the temperate and northern forests and 70 percent of the tree species growing in the tropics. Ectomycorrhizal fungi benefit most conifer species, such as pine, fir, spruce, and hemlock, and hardwoods such as oak, birch, beech, and madrone.
Arbuscular Mycorrhizae
Plants forming arbuscular mycorrhizae (also referred to as “AM”, “VAM“ and “endo mycorrhizae”) are commercially important horticultural and agricultural plants. Unlike the ectomycorrhizae, no external modification of the root accompanies arbuscular mycorrhizae. Arbuscular mycorrhizal fungi benefit ash, gum, maple and other trees as well as shrubs and ornamental plants.
There are few trees that don’t rely on any mycorrhizae in their natural environment, and they are the “weedy species” that grow very quickly following disturbance events and raise havoc with existing mycorrhizal fungi.
Mycorrhizal fungi increase the surface absorbing area of roots by ten to one thousand times, thereby greatly improving the ability of the trees to use soil resources and to communicate with other neighboring trees. They also form an intricate web that captures and assimilates nutrients in the soil. This means that mycorrhizal fungi increase a tree's nutrient uptake by increasing the absorbing surface area of roots. Mycorrhizal fungi release powerful chemicals into the soil that dissolve hard-to-capture nutrients, such as phosphorous, iron, and other “tightly bound” soil nutrients. This extraction process is particularly important in tree nutrition and explains why non-mycorrhizal trees require frequent fertilizer treatments to maintain their health.
Mycorrhizal fungi are involved with a wide variety of other activities that benefit tree establishment and growth. The same extensive network of fungal filaments important to nutrient uptake are also important in water uptake and storage. In soil conditions where there is no irrigation, trees with mycorrhizal fungal filaments attached to their roots are under far less drought stress compared to non-mycorrhizal trees. Suppression of diseases and pathogens are additional benefits for a mycorrhizal tree. Mycorrhizal fungi attack pathogen or disease organisms entering the root zone. For example, excretions of specific antibiotics produced by mycorrhizal fungi immobilize and kill disease organisms. These mycorrhizal fungi protect trees from Phytophthora, Fusarium, and Rhizoctonia diseases.
Mycorrhizal fungi also improve soil structure. Mycorrhizal filaments produce humic compounds and organic “glues” (extracellular polysaccharides) that bind soil particles into aggregates and improve soil porosity. Soil porosity and soil structure positively influence the growth of trees by promoting aeration, water movement into the soil, root growth, and root distribution.
Many practical benefits can be expected from using mycorrhizal fungi in common practices. These include improved survival, healthier growth; more rooting, profuse flowering, and increased fruiting. Benefits also include protection against disease; improved soil structure; and resistance to invasion by non-mycorrhizal or exotic tree species.
The root – mycorrhizal fungi relationship is the best understood subject in the field of soil biology. There are thousands of scientific studies on the subject. The earliest fossil record of the roots on land plants contain the almost identical arbuscular mycorrhizae to what is found today. Most scientists today believe the tree – mycorrhizal relationship allowed aquatic plants to make the transition to the relatively harsh terrestrial environment some 430 million years ago. In nature, mycorrhizae make tree growth possible, linking the roots of trees to the surrounding soil. In nature, neither can survive without the other.
Soils from natural and undisturbed areas generally contain robust and diverse populations of mycorrhizal fungi. Research shows that compaction, erosion, grading, topsoil removal, overgrazing, and the use of soil-less mixes in growing operations often eliminate the mycorrhizal fungi completely.
In a disturbed habitat, the return of mycorrhizae is dependent on the quality and proximity of undisturbed habitats containing suitable fungi. Many cases have been documented where soils in disturbed urban and suburban environments have not formed mycorrhizae even many years after planting and are surviving only through intensive care and maintenance.
Fertilizer alone cannot prevent root disease, improve soil structure, or promote beneficial microbes. Fertilizer alone can lead to other side effects, such as deterioration of water quality, soil structure, and excess soil salinity. The mycorrhizae improve feeder-root production, and better utilization of fertilizer.
Growing trees in a nursery and establishing trees on disturbed sites require an understanding of the many soil processes important in facilitating uptake, storage, and cycling of nutrients and water by tree species. In nature, these activities are largely performed by the microorganisms working hard below the soil surface in the living soil. In past decades, clearing of natural areas and disturbances in suburban and urban environments have substantially reduced microorganism populations. Because above ground and below ground tree/soil systems are tightly interdependent, such changes can result in poor tree survival and health.
Caution
What is clear is that on disturbed and stressful sites, inoculation of mycorrhizae is highly effective. The form and application of the mycorrhizal inoculum depends upon the needs of the applicator. Inoculum can be incorporated into the planting hole at the time of transplanting, watered into porous soils, mixed into soil-less mixes, or directly dipped onto bare roots using gels. Many arborists have had great success collecting their own fresh mycorrhizae. It can be found by digging around the roots of an established tree similar in species to the one being planted. During the digging process, scrape some of the soil off the roots of the trees and relocate that soil over the roots of the newly installed tree. The mycorrhizae on the established tree are found growing right against the roots of the established tree, in the rhizosphere.
Commercial mycorrhizal inoculum comes in granular forms, tablet forms, and powder forms. Purchasing mycorrhizae inoculum from specialty companies has mixed results. While most of the time, the inoculum is fresh and viable, it can also be old and have no viable fungi present in the package. Sometimes the product has dried out, been frozen, or exposed to high heat, all of which will kill the fungi. Because of all these potential problems, the buyer should require the fungi to be fresh and delivered as quickly as possible.
Sources
Amaranthus, Mike, “The Secret to Planting Success”, Mycorrhizal Applications Inc. 2014.
Thurman, Peter and Len Phillips, “Time to Break the Mold”, Pro Arb June 2018.
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 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 with Tales
By Len Phillips
The Tales
Ginkgo biloba commonly called Ginkgo or Maidenhair Tree, is the oldest tree on Earth. It is a significantly different gymnosperm tree not related to any other living tree on the planet. (Gymnosperms are softwood trees such as conifers, which have naked seeds and resin ducts.) Since the ginkgo seeds are not protected by an ovary wall, it can morphologically be considered a gymnosperm, even though it has no needles like other conifers. Ginkgos are also dioecious, meaning that some trees are male and others are female. The species will grow to reach 100 feet (30 meters) or more in height, with a spread of about 30-40 feet (10-13 meters).
According to fossil records, ginkgo has existed on the earth for more than 270 million years. It was growing as a native to North America at one time. In China, fossil records indicate the gingko was commonly planted at the beginning of recorded history. The ginkgo was also widely growing in Korea and parts of Japan. In all countries, some naturalization occurred when ginkgos seedlings developed into large ginkgo forests.
Also according to fossil records, gingko consisted of many species and grew nearly everywhere on the earth's surface. The tree evolved in an era before flowering plants, when ferns, cycads, and cycadeoids dominated riparian environments. Because of the Ice Age, two million years ago, the ginkgo disappeared in fossil records everywhere around the globe except a small area of central China where they have survived to this day. Recent studies indicate a high genetic uniformity among the existing ginkgo trees suggesting that these trees in China may have been grown and preserved by Chinese monks for the past 3,000 years.
Today, Ginkgo biloba is a single species with no known living relatives in the taxonomy division of Ginkgophyta. All other ginkgo species are extinct. Another way of saying this is that Ginkgo biloba is a monotypic species like the Dove Tree, Davidia involucrata, Katsura, Cercidophyllum japonicum, and Dawn Redwood, Metasequoia glyptostroboides, as trees that are the only living species within their genus.
The Tree
Male ginkgo trees have pollen-bearing cones, similar to catkins. Females produce soft, yellow balls, each of which contains a seed. The seeds are a fruit-like product that not only emit a foul odor but are also slippery when they drop down on pavements. (The first time I smelled the ginkgo fruit, I was positive there was vomit somewhere nearby.) Despite their fruit-like appearance, these balls are not technically considered fruits, although people commonly refer to them as such. In China, the tree is widely cultivated and was used by early humans as a source of food, however, excessive consumption can cause bodily harm. Early humans also valued the gingko as a medicine, but, it's medicinal value has not been proven to have any cures or treatments, as the Chinese culture had indicated. It is generally recommended that people not eat too many of the seeds. A very small part of the population seem to have a bad reaction to ginkgo.
One of the things today that makes ginkgos special is that they adapt well to the city landscape and they tolerate heat, air pollution, salt, confined spaces, and soils that may be alkaline, acidic, or compacted. They rarely suffer from insects and diseases, even in urban conditions. They remain healthy because most of the pests and diseases that attack ginkgo, disappeared millions of years ago.
Another unique feature of the ginkgo is that it has a distinctive leaf. The fan-shaped leaf with veins radiating out into the leaf blade, sometimes bifurcating (splitting), but never reconnecting to form a network of veins. Two veins enter the leaf blade at the base and fork repeatedly in two; this is known as dichotomous venation. The leaves are usually 2–4 in (5–10 cm) long, but sometimes grow up to 6 in (15 cm) long. The unique, fan-shaped leaves turn a stunning yellow color in autumn.
An example of how tough the ginkgo tree can be may be seen in Hiroshima, Japan, where six trees growing a short distance from the 1945 atomic bomb explosion were among the few living things in the area to survive the blast. Although charred, they quickly recovered and were soon healthy and growing again. The six survivor trees are still alive today.
Ginkgo first attracted the attention of people about a thousand years ago as a rather unusual nut tree. Then it was moved around and grown for its nuts in China, before making its way into the coastal trade routes to Korea and Japan.
By growing ginkgo trees around the planet, humans have, unlike with many other species, helped ensure the ginkgo’s long-term survival.
Appreciate the ginkgo tree that was growing here when the dinosaurs roamed the planet. This really puts our own species and our own individual existence into a clear perspective. We are not at the center of everything. The universe does not revolve around us. We are only here for a few thousand years. That ought to encourage us to look at the big picture as we think about our relationship with the natural world. If we continue to consume our fossil fuels and climate change continues to heat the planet, in a couple hundred years it will be too hot and too much carbon in the air for the human race to survive. But the ginkgo will live on!
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.
By Len Phillips
The Tales
Ginkgo biloba commonly called Ginkgo or Maidenhair Tree, is the oldest tree on Earth. It is a significantly different gymnosperm tree not related to any other living tree on the planet. (Gymnosperms are softwood trees such as conifers, which have naked seeds and resin ducts.) Since the ginkgo seeds are not protected by an ovary wall, it can morphologically be considered a gymnosperm, even though it has no needles like other conifers. Ginkgos are also dioecious, meaning that some trees are male and others are female. The species will grow to reach 100 feet (30 meters) or more in height, with a spread of about 30-40 feet (10-13 meters).
According to fossil records, ginkgo has existed on the earth for more than 270 million years. It was growing as a native to North America at one time. In China, fossil records indicate the gingko was commonly planted at the beginning of recorded history. The ginkgo was also widely growing in Korea and parts of Japan. In all countries, some naturalization occurred when ginkgos seedlings developed into large ginkgo forests.
Also according to fossil records, gingko consisted of many species and grew nearly everywhere on the earth's surface. The tree evolved in an era before flowering plants, when ferns, cycads, and cycadeoids dominated riparian environments. Because of the Ice Age, two million years ago, the ginkgo disappeared in fossil records everywhere around the globe except a small area of central China where they have survived to this day. Recent studies indicate a high genetic uniformity among the existing ginkgo trees suggesting that these trees in China may have been grown and preserved by Chinese monks for the past 3,000 years.
Today, Ginkgo biloba is a single species with no known living relatives in the taxonomy division of Ginkgophyta. All other ginkgo species are extinct. Another way of saying this is that Ginkgo biloba is a monotypic species like the Dove Tree, Davidia involucrata, Katsura, Cercidophyllum japonicum, and Dawn Redwood, Metasequoia glyptostroboides, as trees that are the only living species within their genus.
The Tree
Male ginkgo trees have pollen-bearing cones, similar to catkins. Females produce soft, yellow balls, each of which contains a seed. The seeds are a fruit-like product that not only emit a foul odor but are also slippery when they drop down on pavements. (The first time I smelled the ginkgo fruit, I was positive there was vomit somewhere nearby.) Despite their fruit-like appearance, these balls are not technically considered fruits, although people commonly refer to them as such. In China, the tree is widely cultivated and was used by early humans as a source of food, however, excessive consumption can cause bodily harm. Early humans also valued the gingko as a medicine, but, it's medicinal value has not been proven to have any cures or treatments, as the Chinese culture had indicated. It is generally recommended that people not eat too many of the seeds. A very small part of the population seem to have a bad reaction to ginkgo.
One of the things today that makes ginkgos special is that they adapt well to the city landscape and they tolerate heat, air pollution, salt, confined spaces, and soils that may be alkaline, acidic, or compacted. They rarely suffer from insects and diseases, even in urban conditions. They remain healthy because most of the pests and diseases that attack ginkgo, disappeared millions of years ago.
Another unique feature of the ginkgo is that it has a distinctive leaf. The fan-shaped leaf with veins radiating out into the leaf blade, sometimes bifurcating (splitting), but never reconnecting to form a network of veins. Two veins enter the leaf blade at the base and fork repeatedly in two; this is known as dichotomous venation. The leaves are usually 2–4 in (5–10 cm) long, but sometimes grow up to 6 in (15 cm) long. The unique, fan-shaped leaves turn a stunning yellow color in autumn.
An example of how tough the ginkgo tree can be may be seen in Hiroshima, Japan, where six trees growing a short distance from the 1945 atomic bomb explosion were among the few living things in the area to survive the blast. Although charred, they quickly recovered and were soon healthy and growing again. The six survivor trees are still alive today.
Ginkgo first attracted the attention of people about a thousand years ago as a rather unusual nut tree. Then it was moved around and grown for its nuts in China, before making its way into the coastal trade routes to Korea and Japan.
By growing ginkgo trees around the planet, humans have, unlike with many other species, helped ensure the ginkgo’s long-term survival.
Appreciate the ginkgo tree that was growing here when the dinosaurs roamed the planet. This really puts our own species and our own individual existence into a clear perspective. We are not at the center of everything. The universe does not revolve around us. We are only here for a few thousand years. That ought to encourage us to look at the big picture as we think about our relationship with the natural world. If we continue to consume our fossil fuels and climate change continues to heat the planet, in a couple hundred years it will be too hot and too much carbon in the air for the human race to survive. But the ginkgo will live on!
Sources
- Beaulieu, David, “Trees & Shrubs - Ginkgo biloba Trees: Fall Foliage Champ”, The Spruce, Updated 01/06/17.
- Missouri Botanical Garden, Ginkgo biloba, Plant Finder,
- Wikipedia, “Ginkgo biloba”, 7 April 2017
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.
Straight Trees
Edited by Len Phillips
Everyone knows that a tree grows up from a seed in the ground. As the tree begins to grow it must work against the force of gravity which would normally pull everything down to the ground surface. Scientists have thought for a long time that it was the internal forces in the wood of the tree that kept the tree growing vertically. Scientists also thought that a tree's bark functions purely to protect the tree from outside damage, much as skin does on people.
In order to grow vertically, trees need two things. The first is a skeletal system which is the trunk and branches. This system is both rigid and strong. However, trees also need a way to control and correct the posture of the tree if something prevents it from growing straight up. This second thing applies forces that work against the gravitational forces that could prevent the tree from growing vertical. Over the years, several studies have suggested that vertical posture of trees are internal forces that work during the formation of fiber in the wood. However, a few recent studies have discovered that bark may play the role and this is what researchers recently set out to confirm.
Newest Study
The aim of the most recent study was to investigate the mechanical contribution of the bark to the up-right growth in trees and to evaluate the contribution of the bark in a diversity of designs and species. The test involved 9 tree species that represent a range of wood types and bark structures. Between 8 and 12 plants of each tree were grown in a lab, from a seed, seedling, or sapling. After being allowed to grow for a period of time, they were replanted at a 45-degree angle and staked.
When the stakes were removed, the trees had developed a curve as they corrected course to grow straight up perpendicular to the ground. But when the bark was removed, the trees lost this curve, suggesting that the bark was playing an instrumental role in keeping the tree pointing towards the sky.
When the researchers studied the interior structure of both stem and bark, they found that the fibers in the bark were organized in a sort of trellis structure. As the tree grows, the circumference of the bark increases; this causes the trellis to generate forces along the stem to keep it growing upright.
When the stem is tilted, growth is more rapid on the upper side of the stem. This causes the trellis to generate an asymmetrical force, which then causes the curvature in the stem. Picture paddling harder on one side of a boat causes it to turn to the opposite direction.
Source
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 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
Everyone knows that a tree grows up from a seed in the ground. As the tree begins to grow it must work against the force of gravity which would normally pull everything down to the ground surface. Scientists have thought for a long time that it was the internal forces in the wood of the tree that kept the tree growing vertically. Scientists also thought that a tree's bark functions purely to protect the tree from outside damage, much as skin does on people.
In order to grow vertically, trees need two things. The first is a skeletal system which is the trunk and branches. This system is both rigid and strong. However, trees also need a way to control and correct the posture of the tree if something prevents it from growing straight up. This second thing applies forces that work against the gravitational forces that could prevent the tree from growing vertical. Over the years, several studies have suggested that vertical posture of trees are internal forces that work during the formation of fiber in the wood. However, a few recent studies have discovered that bark may play the role and this is what researchers recently set out to confirm.
Newest Study
The aim of the most recent study was to investigate the mechanical contribution of the bark to the up-right growth in trees and to evaluate the contribution of the bark in a diversity of designs and species. The test involved 9 tree species that represent a range of wood types and bark structures. Between 8 and 12 plants of each tree were grown in a lab, from a seed, seedling, or sapling. After being allowed to grow for a period of time, they were replanted at a 45-degree angle and staked.
When the stakes were removed, the trees had developed a curve as they corrected course to grow straight up perpendicular to the ground. But when the bark was removed, the trees lost this curve, suggesting that the bark was playing an instrumental role in keeping the tree pointing towards the sky.
When the researchers studied the interior structure of both stem and bark, they found that the fibers in the bark were organized in a sort of trellis structure. As the tree grows, the circumference of the bark increases; this causes the trellis to generate forces along the stem to keep it growing upright.
When the stem is tilted, growth is more rapid on the upper side of the stem. This causes the trellis to generate an asymmetrical force, which then causes the curvature in the stem. Picture paddling harder on one side of a boat causes it to turn to the opposite direction.
Source
- B Clair, B Ghislain, J. Prunier, R. Lehnebach, J. Beauchêne, T. Alméras, “Mechanical contribution of secondary phloem to postural control in trees”, The New Phytologist, Aug 4 2018.
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 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.
Managing Circling Roots
Edited by Len Phillips
Researchers have studied ways to deal with circling roots developing on container grown nursery trees, as well as preventing these roots from developing. The following are the most common ways to deal with this problem.
Mechanical Cutting
Mechanically cutting into the root ball or disturbing a tree’s roots before planting is the standard procedure when planting a tree that has circling roots. Planters cut the root ball to stop circling roots from becoming girdled which may lead to tree stress or tree loss. However, there is no evidence to suggest that mechanical cutting or disturbing the roots before planting is needed to stop further root circling, or that root circling in a container does not continue once planted out into the ground. In addition, there does not appear to be any advantage in cutting the roots that are circling. Circled roots stay in the same position as they grew in their container. Where new roots grow naturally into the soil, old roots start to thicken in their circled position. As they grow, they tighten around the vascular system in the tree’s trunk and restrict the vascular function. This leads to weakly growing or a premature death of the tree.
Studies also found that root slicing before planting to stop the roots from circling did not increase the amount of roots produced after planting. The researchers also found that there was a reduction in shoot growth after root disturbance without daily irrigation. This leads to the problem of making sure the tree gets watered daily to try to reduce the potential problems that root slicing can bring.
Straightening Roots
Trying to physically straighten circling roots does not work either. Sometimes if the roots are very small, they can be somewhat straighten. Larger roots can be pulled a bit, but if the root should happen to crack or even break off, the damage and open wound could cause premature death to the tree.
Copper Coatings
In the not-too-distant past, copper was applied on the inside of a container to prevent roots from growing near the container wall. The chemicals copper hydroxide (CuOH2), copper carbonate (CuCO3) and copper sulfide (CuS) were sprayed on the inside of the container covering the walls and bottom. Copper sulfide was also infused in Kraft paper and placed as a liner inside the container.
When a tree root reached the wall of the container and touched the copper coating, the root tip was killed causing it to produce lateral roots behind the dead tissue. This method did produce a more fibrous root system in the middle of the root ball. However, a number of problems were found with using the copper treatments. The copper paint was sometimes unevenly or badly applied which caused the roots to spiral. This problem only appeared when the tree roots were well developed and at this stage it was too late to correct. Some trees belonging to the Legume family and Protea family were also unsuitable for growth in containers coated with copper. Also many nursery people did not like using chemicals to create a good root system when there were more economical and environmentally friendly ways of doing it.
Container Design
When growers or nursery people are selecting a container, they look at four main features:
Container Shape
Container shape has become an important consideration when nursery people choose a growing container. It has been found that the standard plastic round, smooth walled container creates problems with root circling. This container is great for holding soil, but not great for growing trees.
Some trials were conducted several years ago on six different container types to find their effectiveness in minimizing or preventing the development of circling roots. The containers used were, straight walled, ribbed, square, stepped, low-profiled, and poly bagged.
The poly-bag and stepped pyramid containers were successful in minimizing root circling. The square container, which has holes along the side corners, was also good at preventing roots from circling around the sides of the container but this design encouraged roots to grow to the bottom of the container where roots would begin to circle again. Researches also found problems with the ribbed container. When the container was over filled with growing media, roots were found to grow up and trace the container’s top lip and then the roots circled.
A review in the International Plant Propagators Society (IPPS, 2010) magazine suggested that ribs on the inside of a growing container directed roots to grow downwards to the bottom of the container thus reducing root circling around the container wall. However, it goes on to say that once the root reaches the bottom of the container they start to circle the base. With tap rooted species, once the tap root reached the bottom of the container it begins to circle.
Air Pruning Containers
Containers with holes in the side walls are called air pruning containers. Air pruning containers are designed to prune a root when it reaches the container side wall. This is done by means of directing the root to the opening in the container wall. When the root reaches the opening, the root tip is dehydrated and stops growing. When the root dries out, it then branches laterally behind the dried out root tip creating a more fibrous root system. Air pruned roots have less roots on the outside of the root ball, with more roots in the inner core of the root ball. By air pruning the root, the root is naturally sealed through cauterization. Unlike mechanical methods used to prune roots, the air pruning method does not leave a wound which can provide entry for pathogens and disease.
One problem with air pruning containers is that roots can sense the drier part of the growing media near the air pruning holes. The roots react to this by growing away from the drier area and so do not get air pruned. Some containers have developed a way to catch the root and direct it to the air pruning hole.
Fabrics
Fabric containers can be used above or below ground. When used above ground the root tip doesn’t grow through the fabric. When it reaches the side wall it gets trapped in the fabric and stops elongating. The root becomes round and thick resulting in loss of hormonal dominance over root development. The results of this is secondary branching behind this point. This technique creates a fibrous root system inside the container.
Fabric containers can also be used below ground. The roots will grow through the pores in the fabric which becomes tighter as the root grows. The root constriction stops the root from getting too large. When the root is restricted from thickening it causes root branching behind this point inside the container creating a fibrous root system. Due to the root constriction, sugars from the leaves are stopped from going beyond the fabric wall.
This creates nodules on the root in the container. When planted into the open ground these nodules then produce rapid root growth into the surrounding soil. However, researchers have found there are some problems with using fabric containers. When the fabric is removed from the root ball outer surface, it will remove any roots that were either trapped in the fabric or growing through the fabric. Additionally, the fabric usually has to be cut away from the root ball meaning it cannot be used again. The researchers found that growing a tree for too long in fabric containers can cause roots to circle but if the tree is managed correctly and planted in an appropriate sized fabric container there should be no problem.
Researchers have found that trees with taproots are more susceptible to circling than trees with a fibrous root system. They suggest that taproot trees should have its roots pruned when it is still a seedling. Also trees growing in a container get all their water, nutrients and anchorage from the container it grows in, so it does not need the taproot to grow to the depths it does in open ground, so it can be pruned. However, trees growing this way have a reduced need to search for water, so when they are transplanted to the landscape, additional watering is necessary for the first month after planting.
Best Solutions
Many techniques have been used to reduce root circling: chemical pruning, air pruning, constriction, or by using different container wall configurations. All these products reduce root circling but nearly all have some flaws. The nursery standard black plastic container has problems with root circling but it is still the most widely used container in the industry. The black standard container does produce the highest amount of circling roots compared to every other treatment. It also found that the standard black container produces the largest tree. Air pruned roots produce the highest amount of branched roots.
A new generation of containers are coming into the market that have been developed specifically for growing healthy trees. Researchers indicate that this new type of fabric container will be made from recycled water bottles blended with different types of natural recycled fibers. This container is made to be the most sustainable growing container available in the market today. The container is long lasting and durable while the fabric encourages trees to develop strong, lateral, dense, fibrous roots rather than circle and harm the tree. For more information click on A New Tree Container link.
There is no single solution that is best. We are not there yet!
Source
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 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
Researchers have studied ways to deal with circling roots developing on container grown nursery trees, as well as preventing these roots from developing. The following are the most common ways to deal with this problem.
Mechanical Cutting
Mechanically cutting into the root ball or disturbing a tree’s roots before planting is the standard procedure when planting a tree that has circling roots. Planters cut the root ball to stop circling roots from becoming girdled which may lead to tree stress or tree loss. However, there is no evidence to suggest that mechanical cutting or disturbing the roots before planting is needed to stop further root circling, or that root circling in a container does not continue once planted out into the ground. In addition, there does not appear to be any advantage in cutting the roots that are circling. Circled roots stay in the same position as they grew in their container. Where new roots grow naturally into the soil, old roots start to thicken in their circled position. As they grow, they tighten around the vascular system in the tree’s trunk and restrict the vascular function. This leads to weakly growing or a premature death of the tree.
Studies also found that root slicing before planting to stop the roots from circling did not increase the amount of roots produced after planting. The researchers also found that there was a reduction in shoot growth after root disturbance without daily irrigation. This leads to the problem of making sure the tree gets watered daily to try to reduce the potential problems that root slicing can bring.
Straightening Roots
Trying to physically straighten circling roots does not work either. Sometimes if the roots are very small, they can be somewhat straighten. Larger roots can be pulled a bit, but if the root should happen to crack or even break off, the damage and open wound could cause premature death to the tree.
Copper Coatings
In the not-too-distant past, copper was applied on the inside of a container to prevent roots from growing near the container wall. The chemicals copper hydroxide (CuOH2), copper carbonate (CuCO3) and copper sulfide (CuS) were sprayed on the inside of the container covering the walls and bottom. Copper sulfide was also infused in Kraft paper and placed as a liner inside the container.
When a tree root reached the wall of the container and touched the copper coating, the root tip was killed causing it to produce lateral roots behind the dead tissue. This method did produce a more fibrous root system in the middle of the root ball. However, a number of problems were found with using the copper treatments. The copper paint was sometimes unevenly or badly applied which caused the roots to spiral. This problem only appeared when the tree roots were well developed and at this stage it was too late to correct. Some trees belonging to the Legume family and Protea family were also unsuitable for growth in containers coated with copper. Also many nursery people did not like using chemicals to create a good root system when there were more economical and environmentally friendly ways of doing it.
Container Design
When growers or nursery people are selecting a container, they look at four main features:
- ease of handling;
- stack-ability;
- price;
- container designs that prevent root circling and create a more fibrous root system. Some of the design features used are: container shapes, fabrics, bottomless containers, and holes in the container side walls.
Container Shape
Container shape has become an important consideration when nursery people choose a growing container. It has been found that the standard plastic round, smooth walled container creates problems with root circling. This container is great for holding soil, but not great for growing trees.
Some trials were conducted several years ago on six different container types to find their effectiveness in minimizing or preventing the development of circling roots. The containers used were, straight walled, ribbed, square, stepped, low-profiled, and poly bagged.
The poly-bag and stepped pyramid containers were successful in minimizing root circling. The square container, which has holes along the side corners, was also good at preventing roots from circling around the sides of the container but this design encouraged roots to grow to the bottom of the container where roots would begin to circle again. Researches also found problems with the ribbed container. When the container was over filled with growing media, roots were found to grow up and trace the container’s top lip and then the roots circled.
A review in the International Plant Propagators Society (IPPS, 2010) magazine suggested that ribs on the inside of a growing container directed roots to grow downwards to the bottom of the container thus reducing root circling around the container wall. However, it goes on to say that once the root reaches the bottom of the container they start to circle the base. With tap rooted species, once the tap root reached the bottom of the container it begins to circle.
Air Pruning Containers
Containers with holes in the side walls are called air pruning containers. Air pruning containers are designed to prune a root when it reaches the container side wall. This is done by means of directing the root to the opening in the container wall. When the root reaches the opening, the root tip is dehydrated and stops growing. When the root dries out, it then branches laterally behind the dried out root tip creating a more fibrous root system. Air pruned roots have less roots on the outside of the root ball, with more roots in the inner core of the root ball. By air pruning the root, the root is naturally sealed through cauterization. Unlike mechanical methods used to prune roots, the air pruning method does not leave a wound which can provide entry for pathogens and disease.
One problem with air pruning containers is that roots can sense the drier part of the growing media near the air pruning holes. The roots react to this by growing away from the drier area and so do not get air pruned. Some containers have developed a way to catch the root and direct it to the air pruning hole.
Fabrics
Fabric containers can be used above or below ground. When used above ground the root tip doesn’t grow through the fabric. When it reaches the side wall it gets trapped in the fabric and stops elongating. The root becomes round and thick resulting in loss of hormonal dominance over root development. The results of this is secondary branching behind this point. This technique creates a fibrous root system inside the container.
Fabric containers can also be used below ground. The roots will grow through the pores in the fabric which becomes tighter as the root grows. The root constriction stops the root from getting too large. When the root is restricted from thickening it causes root branching behind this point inside the container creating a fibrous root system. Due to the root constriction, sugars from the leaves are stopped from going beyond the fabric wall.
This creates nodules on the root in the container. When planted into the open ground these nodules then produce rapid root growth into the surrounding soil. However, researchers have found there are some problems with using fabric containers. When the fabric is removed from the root ball outer surface, it will remove any roots that were either trapped in the fabric or growing through the fabric. Additionally, the fabric usually has to be cut away from the root ball meaning it cannot be used again. The researchers found that growing a tree for too long in fabric containers can cause roots to circle but if the tree is managed correctly and planted in an appropriate sized fabric container there should be no problem.
Researchers have found that trees with taproots are more susceptible to circling than trees with a fibrous root system. They suggest that taproot trees should have its roots pruned when it is still a seedling. Also trees growing in a container get all their water, nutrients and anchorage from the container it grows in, so it does not need the taproot to grow to the depths it does in open ground, so it can be pruned. However, trees growing this way have a reduced need to search for water, so when they are transplanted to the landscape, additional watering is necessary for the first month after planting.
Best Solutions
Many techniques have been used to reduce root circling: chemical pruning, air pruning, constriction, or by using different container wall configurations. All these products reduce root circling but nearly all have some flaws. The nursery standard black plastic container has problems with root circling but it is still the most widely used container in the industry. The black standard container does produce the highest amount of circling roots compared to every other treatment. It also found that the standard black container produces the largest tree. Air pruned roots produce the highest amount of branched roots.
A new generation of containers are coming into the market that have been developed specifically for growing healthy trees. Researchers indicate that this new type of fabric container will be made from recycled water bottles blended with different types of natural recycled fibers. This container is made to be the most sustainable growing container available in the market today. The container is long lasting and durable while the fabric encourages trees to develop strong, lateral, dense, fibrous roots rather than circle and harm the tree. For more information click on A New Tree Container link.
There is no single solution that is best. We are not there yet!
Source
- Blackweir, Damien, “An investigation into root circling in potted nursery stock”, Waterford Institute of Technology, Waterford, Ireland, 2010.
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 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.