Archive #56 from Online Seminars for Municipal Arborists – May/June 2014
Sections Click on the green words for more information
What Can We Do About Global Warming?
Edited by Len Phillips
Global warming is driving humanity toward a whole new level of worldly risks, according to a report from a United Nations scientific panel. The panel of scientists indicated that a wild climate ride has only just begun. Nobody on the planet is going to be untouched by the impacts of climate change. The twenty-first century disasters such as killer heat waves in Europe, wildfires in the United States, droughts in Australia, and deadly flooding in Mozambique, Thailand, and Pakistan highlight how vulnerable humanity is to extreme weather. The dangers are going to worsen as the climate changes more. This is all according to the Intergovernmental Panel on Climate Change. This group represents more than 100 governments who unanimously approved the scientist–written report which is aimed at the world’s political leaders.
Other risks mentioned in the report involve the price and availability of food, and to a lesser and more qualified extent, more diseases, financial costs, and even world peace is at risk. The impacts are going to be more in number and size, and sooner than the scientists had anticipated. The report predicts that the first hits would be to plants and animals, both on land and in the acidifying oceans. Climate change will worsen problems such as poverty, sickness, violence, and refugees. If society does not change, the future looks even worse. The increasing magnitudes of warming will increase the likelihood of severe, pervasive, and irreversible impacts.
According to the U.S. Census Bureau, about 79% of the population lives on 3.1% of the total land area within the US. According to the scientists representing the US, this fact has resulted in urban heat islands where temperatures are averaging several degrees warmer than the surrounding countryside. This is causing great stress on the urban forests. These higher temperatures along with reduced rainfall in many regions have increased the number of diseases and pests within the urban forests.
What can we, as arborists do about urban heat islands?
This list could go on and on. Let me know if you have other ideas to save energy and cool our cities down. Better yet, if you have a lot of ideas, send them to me and you may be published in the next Online Seminar.
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 .5 CEUs toward Certified Arborist, Utility Specialist, Municipal Specialist, Tree Worker Specialist, Aerial Lift 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 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
Global warming is driving humanity toward a whole new level of worldly risks, according to a report from a United Nations scientific panel. The panel of scientists indicated that a wild climate ride has only just begun. Nobody on the planet is going to be untouched by the impacts of climate change. The twenty-first century disasters such as killer heat waves in Europe, wildfires in the United States, droughts in Australia, and deadly flooding in Mozambique, Thailand, and Pakistan highlight how vulnerable humanity is to extreme weather. The dangers are going to worsen as the climate changes more. This is all according to the Intergovernmental Panel on Climate Change. This group represents more than 100 governments who unanimously approved the scientist–written report which is aimed at the world’s political leaders.
Other risks mentioned in the report involve the price and availability of food, and to a lesser and more qualified extent, more diseases, financial costs, and even world peace is at risk. The impacts are going to be more in number and size, and sooner than the scientists had anticipated. The report predicts that the first hits would be to plants and animals, both on land and in the acidifying oceans. Climate change will worsen problems such as poverty, sickness, violence, and refugees. If society does not change, the future looks even worse. The increasing magnitudes of warming will increase the likelihood of severe, pervasive, and irreversible impacts.
According to the U.S. Census Bureau, about 79% of the population lives on 3.1% of the total land area within the US. According to the scientists representing the US, this fact has resulted in urban heat islands where temperatures are averaging several degrees warmer than the surrounding countryside. This is causing great stress on the urban forests. These higher temperatures along with reduced rainfall in many regions have increased the number of diseases and pests within the urban forests.
What can we, as arborists do about urban heat islands?
- We must begin by informing as many people as we can about the benefits of healthy trees, shrubs, and plantings in the urban environment. Arborists must also relay this message to public officials. Although about one-third of our cities have begun adapting to climate change with programs to reduce energy consumption, conserve water, and improve landscapes, more needs to be done. For example, very few people are looking at the urban canopy or how landscapes might affect the overall natural climatic balance. Most political leaders do not know that arborists have the technical know how and experience to provide invaluable assistance in areas such as proper management of herbicides, water conservation, planting designs, and efforts in these areas might be of more benefit than solar panels on the roof.
- More planners need to be aware of the positive effects of how adding green planting and maintaining our urban canopy properly would make a substantial difference in lowering the carbon emissions, increase oxygen in the atmosphere, and help sustain a healthier urban environment. For example, very little thought is given to making our traffic islands and parking lots greener and cooler with more trees.
- As arborists, let us try to plant as many trees as we can afford. I recommend planting bare root trees because you can plant twice as many as the B&B trees in your budget. I recommend you gather volunteers to help you plant these light-weight trees. Without a contractor doing the planting, you can plant even more bare root trees. Re-read the articles found in the Topic “All About Bare Root Trees” especially the section pertaining to a “Tree Planting Program that Works”.
- If possible be sure the trees have fibrous root systems that will tolerate the urban soils. Read more about fibrous roots also found in the Topic page mentioned above.
- During the planting process, follow the directions mentioned in “Tips for Planting Bare Root Trees” in this same Topic.
- Consider adding a shovel full of rich loam from under a nearby established tree to add some beneficial mycorrhizal fungi to help every new tree being planted so it will thrive in future years, or sprinkle some fungal inoculants over the bare roots, if that works for you.
- Be sure you are doing your part to conserve energy and water. To conserve fuel, do you turn off your engine when the truck is not in use? Are your trips to and from the job sites, taking the shortest routes? Do you have all the tools you need to do the job, so you do not have to run back to the garage for something else? Do you combine your errands into one trip instead of many? Are you using vegetable oil to replace the bar oil in your chain saw?
This list could go on and on. Let me know if you have other ideas to save energy and cool our cities down. Better yet, if you have a lot of ideas, send them to me and you may be published in the next Online Seminar.
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 .5 CEUs toward Certified Arborist, Utility Specialist, Municipal Specialist, Tree Worker Specialist, Aerial Lift 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 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.
Problem Employees
Edited by Len Phillips
Do you have an employee who has become unreliable or hard to work with? Managing problem employees in an effective manner is important for keeping your department running efficiently and protecting your rights as an employer.
Employee Handbook
Employee handbooks should cover behavior expectations such as your regular work hours, the work week, vacation time, and holiday time. It should also explain procedures for requesting time off, clocking in and out, sick leave guidelines, and how to raise a concern with management. Handbooks should thoroughly and clearly explain the disciplinary process that your department uses.
Employee handbooks are the best way to give employees a guide of what is expected from them, how the department works, and how they can expect to be treated when guidelines are not followed. Go over the general department guidelines and policies with each employee when they are hired so you can answer their questions and ensure they understand all the rules of employment and where they can go for assistance.
Addressing Problems
If you notice an employee having problems, address it right away. Letting the problem behavior persist and hoping it will go away, is a recipe for disaster. When you let problem behavior continue, it sends the wrong message to the problem employee as well as to the other employees. They will all believe that the behavior is acceptable because you have not said otherwise.
Once you have identified a problem behavior, document it and collect information that can substantiate the problem the employee is having. The severity of the issue determines how much investigating you need to conduct. If the employee was late for work, a simple printout of their time card may be enough. If the employee has been accused of harassing another employee, or is suspected of having a problem with drugs or alcohol, you will want to interview others that may have witnessed the behavior.
Addressing the Employee
Before pulling the employee aside to discuss the behavior, make sure you organize your thoughts and what you want to cover during the talk. Bring copies of any documentation for the employee so he or she can look at the issues or concerns on their own time, after you have talked to the person.
Pull the employee aside at a time and place that will minimize distractions for both of you and will also respect the employee's privacy. Embarrassing an employee in front of others can turn a fixable situation into further problems. When you sit down and talk to the employee, your goal should be to help the employee improve his or her performance. Explain to them why their behavior is bad for the department, why it disrupts other employees, or is a safety concern. Let them know why it is important for him or her to change their behavior.
Once you have explained the problem and showed the employee your documentation, allow the person to suggest actions they will take to correct the situation and prevent a re-occurrence in the future. Provide some of your own suggestions and come to an agreement with the employee on what actions will be taken and what the time frame will be for implementing the agreed upon changes.
Resist the urge to issue verbal warnings or not document the conclusions you reach when meeting with the employee. Write down what you ultimately agree to and give a copy to the employee so they understand the importance of the conversation you had with them. Then put a copy of the agreement into the employee's file and let the employee know that you will be doing so. It is hard to keep up with all the paperwork, but it is important to do so, especially if legal problems develop during a termination procedure.
Termination Process
Although you and the employee have already discussed the problem, a verbal reminder or warning is not enough. You must create documentation and evidence (a.k.a. a paper trail) for all further proceedings that may be necessary between you and the employee. This information will be essential, if and when you terminate the employee. Every time you meet with an employee to discuss a problem, you should create a document for their file, and which you might need in the future to support your decision. Check on the employee's behavior regularly and be sure to compliment or reward compliance with the agreement you came to.
Be sure to make all disciplinary actions progressive for the repeated problem. For example, after the first discussion and written warning, follow up with a 2 – day suspension. If this does not bring an end to the continuing problem, issue a 2 – week suspension and the final offense will be termination. Note that the suspensions are listed in twos. This way if you have a union or the employee pleads hardship, you can cut the penalty in half. The suspension is still in effect and you have made your point. Also note in your written warnings what the next penalty will be for failure to end the problem.
No matter how much counseling and mentoring takes place, sometimes a problem employee is unable to overcome the behavioral obstacles they face. It does not matter whether this is due to an unwillingness to change or other things going on in the employee’s life, sometimes you have to fire people.
If the problem behavior continues, choose a time to give the employee a final warning and let them know that termination will be the next step. Put this warning in writing as well and clearly explain why the employee must figure out how to change.
Final Termination
Even though the employee being terminated has caused you all sorts of headaches and problems, still treat them with respect and dignity. Perhaps try to have the termination meeting at a time when other employees are not around. Prepare for the meeting and make a checklist of things you need to cover. If the employee has borrowed tools, make sure you get them back before you schedule the meeting. Also if the employee has access to confidential information or materials, make sure that is accounted for as well. Have the final paycheck ready to hand over at the meeting, and the written letter stating that they are terminated. It is also a good idea to have another employee or union representative sit in on the meeting as a witness. If you have a human resources person, it would be ideal to have them there as well and be sure they have reviewed the employee’s file to be sure you are on solid ground.
Terminations are emotionally charged and no matter how deserved, the termination can result in a variety of behaviors. Most people will ask for an explanation, but this is really an attempt to engage you in further conversation and a plea for one more chance. Some people cry and others may yell. Often the employee will want to bargain with you so that you give them another chance. It is best not to engage in this type of discussion. Do not go into detail but instead tell them that they are no longer a good fit for the department and they are no longer needed. Depending on the type of position and the circumstance of the termination, you may want to consider a severance agreement for the employee if that is possible. If a labor union is involved, there may be several more requirements.
Consider how the employee will exit the property and be prepared to walk with them to their vehicle to ensure they do not vandalize anything or remove any department property. If the employee has a desk or locker be sure to have a few empty boxes around so that they can take all of their personal belongings with them and not need to return at a later date. Think about any additional security issues which may need to be addressed once the employee leaves. Things such as lock combinations, passwords, and extra key hiding spots are often over looked during a termination.
Once the termination has taken place, move on and encourage other employees to move on as well. Do not engage in conversation with other employees about the terminated person.
Sometimes an employee just is not a good fit for your department. Many times employees are able and willing to fix their behavior right away when a problem is pointed out. Either way, your department’s rights and reputation are at stake so be sure to have a plan for every step.
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 .5 CEUs toward Certified Arborist, Utility Specialist, 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 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
Do you have an employee who has become unreliable or hard to work with? Managing problem employees in an effective manner is important for keeping your department running efficiently and protecting your rights as an employer.
Employee Handbook
Employee handbooks should cover behavior expectations such as your regular work hours, the work week, vacation time, and holiday time. It should also explain procedures for requesting time off, clocking in and out, sick leave guidelines, and how to raise a concern with management. Handbooks should thoroughly and clearly explain the disciplinary process that your department uses.
Employee handbooks are the best way to give employees a guide of what is expected from them, how the department works, and how they can expect to be treated when guidelines are not followed. Go over the general department guidelines and policies with each employee when they are hired so you can answer their questions and ensure they understand all the rules of employment and where they can go for assistance.
Addressing Problems
If you notice an employee having problems, address it right away. Letting the problem behavior persist and hoping it will go away, is a recipe for disaster. When you let problem behavior continue, it sends the wrong message to the problem employee as well as to the other employees. They will all believe that the behavior is acceptable because you have not said otherwise.
Once you have identified a problem behavior, document it and collect information that can substantiate the problem the employee is having. The severity of the issue determines how much investigating you need to conduct. If the employee was late for work, a simple printout of their time card may be enough. If the employee has been accused of harassing another employee, or is suspected of having a problem with drugs or alcohol, you will want to interview others that may have witnessed the behavior.
Addressing the Employee
Before pulling the employee aside to discuss the behavior, make sure you organize your thoughts and what you want to cover during the talk. Bring copies of any documentation for the employee so he or she can look at the issues or concerns on their own time, after you have talked to the person.
Pull the employee aside at a time and place that will minimize distractions for both of you and will also respect the employee's privacy. Embarrassing an employee in front of others can turn a fixable situation into further problems. When you sit down and talk to the employee, your goal should be to help the employee improve his or her performance. Explain to them why their behavior is bad for the department, why it disrupts other employees, or is a safety concern. Let them know why it is important for him or her to change their behavior.
Once you have explained the problem and showed the employee your documentation, allow the person to suggest actions they will take to correct the situation and prevent a re-occurrence in the future. Provide some of your own suggestions and come to an agreement with the employee on what actions will be taken and what the time frame will be for implementing the agreed upon changes.
Resist the urge to issue verbal warnings or not document the conclusions you reach when meeting with the employee. Write down what you ultimately agree to and give a copy to the employee so they understand the importance of the conversation you had with them. Then put a copy of the agreement into the employee's file and let the employee know that you will be doing so. It is hard to keep up with all the paperwork, but it is important to do so, especially if legal problems develop during a termination procedure.
Termination Process
Although you and the employee have already discussed the problem, a verbal reminder or warning is not enough. You must create documentation and evidence (a.k.a. a paper trail) for all further proceedings that may be necessary between you and the employee. This information will be essential, if and when you terminate the employee. Every time you meet with an employee to discuss a problem, you should create a document for their file, and which you might need in the future to support your decision. Check on the employee's behavior regularly and be sure to compliment or reward compliance with the agreement you came to.
Be sure to make all disciplinary actions progressive for the repeated problem. For example, after the first discussion and written warning, follow up with a 2 – day suspension. If this does not bring an end to the continuing problem, issue a 2 – week suspension and the final offense will be termination. Note that the suspensions are listed in twos. This way if you have a union or the employee pleads hardship, you can cut the penalty in half. The suspension is still in effect and you have made your point. Also note in your written warnings what the next penalty will be for failure to end the problem.
No matter how much counseling and mentoring takes place, sometimes a problem employee is unable to overcome the behavioral obstacles they face. It does not matter whether this is due to an unwillingness to change or other things going on in the employee’s life, sometimes you have to fire people.
If the problem behavior continues, choose a time to give the employee a final warning and let them know that termination will be the next step. Put this warning in writing as well and clearly explain why the employee must figure out how to change.
Final Termination
Even though the employee being terminated has caused you all sorts of headaches and problems, still treat them with respect and dignity. Perhaps try to have the termination meeting at a time when other employees are not around. Prepare for the meeting and make a checklist of things you need to cover. If the employee has borrowed tools, make sure you get them back before you schedule the meeting. Also if the employee has access to confidential information or materials, make sure that is accounted for as well. Have the final paycheck ready to hand over at the meeting, and the written letter stating that they are terminated. It is also a good idea to have another employee or union representative sit in on the meeting as a witness. If you have a human resources person, it would be ideal to have them there as well and be sure they have reviewed the employee’s file to be sure you are on solid ground.
Terminations are emotionally charged and no matter how deserved, the termination can result in a variety of behaviors. Most people will ask for an explanation, but this is really an attempt to engage you in further conversation and a plea for one more chance. Some people cry and others may yell. Often the employee will want to bargain with you so that you give them another chance. It is best not to engage in this type of discussion. Do not go into detail but instead tell them that they are no longer a good fit for the department and they are no longer needed. Depending on the type of position and the circumstance of the termination, you may want to consider a severance agreement for the employee if that is possible. If a labor union is involved, there may be several more requirements.
Consider how the employee will exit the property and be prepared to walk with them to their vehicle to ensure they do not vandalize anything or remove any department property. If the employee has a desk or locker be sure to have a few empty boxes around so that they can take all of their personal belongings with them and not need to return at a later date. Think about any additional security issues which may need to be addressed once the employee leaves. Things such as lock combinations, passwords, and extra key hiding spots are often over looked during a termination.
Once the termination has taken place, move on and encourage other employees to move on as well. Do not engage in conversation with other employees about the terminated person.
Sometimes an employee just is not a good fit for your department. Many times employees are able and willing to fix their behavior right away when a problem is pointed out. Either way, your department’s rights and reputation are at stake so be sure to have a plan for every step.
Source
- McGuiness, Patrick, “Effectively Handling Problem Employees”, Tree Care Industry, September, 2013.
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 .5 CEUs toward Certified Arborist, Utility Specialist, 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 gibneyCE.com’. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website. *SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Tree of the Seminar 56
By Len Phillips
The ‘Redmond’ Linden is a hybrid that makes a handsome street tree. This tree has a uniform growing habit that is a dense pyramid shape and it tolerates most urban sites. This information has been gathered from personal observations of the author, living in Massachusetts, Zone 6, and information provided by J. Frank Schmidt & Son nursery.
Botanical Name: Tilia americana x euchlora 'Redmond'
Trade Name: ‘Redmond’ American Linden
Parentage: Introduced by Plumfield Nurseries in Fremont, Nebraska
Family: Tiliaceae
Introduction: 1927
Height: 30'- 40'
Spread: 25'- 30'
Form: Densely pyramid shape
Bloom Period: Mid to late June
Flower: Fragrant and yellow
Fruit: 1/3" grayish nutlet
Summer Foliage: Light green in summer, very large leaves
Autumn Foliage: Yellowish in the fall
Winter Color: Bark provides winter interest
Bark: Gray, brown, and maroon
Habitat: Canada to Virginia, North Dakota to Texas
Culture: Likes well drained soil, any pH, full sun to partial shade, tolerates heat, drought, and air pollution
Hardiness Zone: 3 – 8
Growth Rate: Moderate, less than 1 foot per year, develops a heavy caliper as a young tree
Pest Resistance: Most pest issues are minor except for foliage feeding insects
Storm Resistance: Excellent
Salt Resistance: Excellent
Planting: Transplants easily, quick recovery, bare root is best, suitable for CU-Structural Soil planting
Pruning: Prune at planting and 3 years later to mature form, withstands severe pruning, may only require pruning of basal sprouts and removal of some potential crotch problems
Propagating: Budded onto seedling understock and softwood cuttings
Design Uses: Well suited for street tree planting, very coarse texture
Companions: Use with ground covers such as Vinca and Pachysandra if the plants are established when tree is first planted. Dense shade will discourage grass and most plants from growing under this tree.
Other Comments: Very symmetrical appearance. Ideal for sidewalk planting.
Photos: 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 .5 CEUs toward Certified Arborist, Utility Specialist, Municipal Specialist, Tree Worker Specialist, Aerial Life 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 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 ‘Redmond’ Linden is a hybrid that makes a handsome street tree. This tree has a uniform growing habit that is a dense pyramid shape and it tolerates most urban sites. This information has been gathered from personal observations of the author, living in Massachusetts, Zone 6, and information provided by J. Frank Schmidt & Son nursery.
Botanical Name: Tilia americana x euchlora 'Redmond'
Trade Name: ‘Redmond’ American Linden
Parentage: Introduced by Plumfield Nurseries in Fremont, Nebraska
Family: Tiliaceae
Introduction: 1927
Height: 30'- 40'
Spread: 25'- 30'
Form: Densely pyramid shape
Bloom Period: Mid to late June
Flower: Fragrant and yellow
Fruit: 1/3" grayish nutlet
Summer Foliage: Light green in summer, very large leaves
Autumn Foliage: Yellowish in the fall
Winter Color: Bark provides winter interest
Bark: Gray, brown, and maroon
Habitat: Canada to Virginia, North Dakota to Texas
Culture: Likes well drained soil, any pH, full sun to partial shade, tolerates heat, drought, and air pollution
Hardiness Zone: 3 – 8
Growth Rate: Moderate, less than 1 foot per year, develops a heavy caliper as a young tree
Pest Resistance: Most pest issues are minor except for foliage feeding insects
Storm Resistance: Excellent
Salt Resistance: Excellent
Planting: Transplants easily, quick recovery, bare root is best, suitable for CU-Structural Soil planting
Pruning: Prune at planting and 3 years later to mature form, withstands severe pruning, may only require pruning of basal sprouts and removal of some potential crotch problems
Propagating: Budded onto seedling understock and softwood cuttings
Design Uses: Well suited for street tree planting, very coarse texture
Companions: Use with ground covers such as Vinca and Pachysandra if the plants are established when tree is first planted. Dense shade will discourage grass and most plants from growing under this tree.
Other Comments: Very symmetrical appearance. Ideal for sidewalk planting.
Photos: 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 .5 CEUs toward Certified Arborist, Utility Specialist, Municipal Specialist, Tree Worker Specialist, Aerial Life 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 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.
How Do Trees Begin?
Edited by Len Phillips
Have you ever wondered how trees begin? You know it is from seeds, but what tells the seed to begin to grow? Then you have to wonder, how does the seed know the conditions are just right so the embryo will be able to grow into a seedling and then into a tree?
Let's start with “germination” which is defined as the growth of an embryonic tree contained within a seed. It results in the formation of a tree seedling. Seed germination depends on both internal and external conditions being just right to support seedling growth. Often this depends on the individual seed variety and is closely linked to the ecological conditions of a tree's natural habitat.
When seeds are being formed, most trees store food as a reserve within the seed itself. The food consists of starch, proteins, and oils. This food reserve provides nourishment to push the growth of an embryonic tree. When the seed imbibes water, hydrolytic enzymes are activated which break down these stored food resources into metabolically useful chemicals that will begin the growth process. There will be enough food to keep the embryonic tree growing until the primary leaves and roots begin photosynthesis, the embryonic tree then becomes a seedling growing on its own.
Inducing Germination
The most important external factors to induce germination include temperature, water, oxygen, and sometimes light or darkness. Various trees require different environmental trigger levels for successful seed germination.
Scarification
Any process of breaking, scratching, or altering the seed coat through chemical or thermal methods, such as freezing over winter, may be necessary to make it permeable to water and gases. This process is known as scarification. Some seeds have impermeable seed coats that prevent oxygen and water from entering the seed, causing a type of physical dormancy which is broken when the seed coat is worn away enough to allow gas exchange and water uptake from the environment. In nature, some seeds require particular conditions to germinate, such as the heat of a wildfire or soaking in a body of water for a long period of time. Others need to be passed through a bird or animal's digestive tract to weaken the seed coat enough to allow the embryonic tree to emerge.
For mechanical scarification, seed coats can be scratched with a metal file, rubbed with sandpaper, nicked with a knife, or cracked gently with a hammer to weaken the seed coat. Scarification of seeds can also be achieved by imbibing them in concentrated sulfuric acid at appropriate concentrations and durations of treatment. Another scarification method involves the use of hot water for brief periods. Scarified seeds should be planted as soon as possible after treatment as they do not store well.
Breaking Dormancy
Some live seeds are dormant and need more time, and/or need to be subjected to specific environmental conditions before they will germinate. Seed dormancy can originate in different parts of the seed. Dormancy breaking often involves changes in membranes, initiated by certain hormones, notably gibberellin, which ends seed dormancy.
Roots
First to emerge from the seed coat is the primary root, or radicle as it is called in the embryo. This radicle is composed of one major root that is thicker at its base and tapers down toward the growing tip. Early root growth is one of the functions of the apical meristem located near the tip of the root. The meristem cells more or less continuously divide, producing more meristem, root cap cells (these are sacrificed to protect the meristem), and undifferentiated root cells. The latter become the primary tissues of the root, first undergoing elongation, a process that pushes the root tip forward in the growing medium. Gradually these cells differentiate and mature into specialized cells of the root tissues.
After the embryonic seedling emerges from the seed coat and starts growing roots and leaves, the embryonic seedling's food reserves are quickly exhausted. At this point, photosynthesis provides the energy needed for continued growth and the seedling now requires a continuous supply of water, nutrients, and light. Most tree species grow a taproot from the seed until moisture or an obstacle is reached, and the seedling can then focus on spreading structural roots and manufacturing food.
Tree roots will generally grow in any direction where the correct environment of air, mineral nutrients and water exists to meet the tree's needs. Roots will shrink away from dry, or other poor soil conditions.
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 .5 CEUs toward Certified Arborist, 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 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
Have you ever wondered how trees begin? You know it is from seeds, but what tells the seed to begin to grow? Then you have to wonder, how does the seed know the conditions are just right so the embryo will be able to grow into a seedling and then into a tree?
Let's start with “germination” which is defined as the growth of an embryonic tree contained within a seed. It results in the formation of a tree seedling. Seed germination depends on both internal and external conditions being just right to support seedling growth. Often this depends on the individual seed variety and is closely linked to the ecological conditions of a tree's natural habitat.
When seeds are being formed, most trees store food as a reserve within the seed itself. The food consists of starch, proteins, and oils. This food reserve provides nourishment to push the growth of an embryonic tree. When the seed imbibes water, hydrolytic enzymes are activated which break down these stored food resources into metabolically useful chemicals that will begin the growth process. There will be enough food to keep the embryonic tree growing until the primary leaves and roots begin photosynthesis, the embryonic tree then becomes a seedling growing on its own.
Inducing Germination
The most important external factors to induce germination include temperature, water, oxygen, and sometimes light or darkness. Various trees require different environmental trigger levels for successful seed germination.
- Temperature affects cell metabolism and growth rates. Seeds from different species and even seeds from the same tree germinate over a wide range of temperatures. This temperature range limits when they will germinate and they will not do so above or below the preferred range.
- Water is required for germination. Most seeds need enough moisture for the embryos but not enough to soak them. The uptake of water by seeds is called imbibition, which leads to the swelling of the food reserves within the seed, which causes the breaking of the seed coat. Mature seeds are often extremely dry and need to take in significant amounts of water, relative to the dry weight of the seed, before cellular metabolism and growth can begin.
- Oxygen is required by the germinating seed for metabolism. Oxygen is used in aerobic respiration, the main source of the seedling's energy until it grows leaves. Oxygen is found in soil pore spaces. If a seed is buried too deeply within the soil or the soil is waterlogged, the seed can be oxygen starved and germination will be delayed. The seed will also die if too much water occurs after the germination process has started.
- Light or darkness can be an environmental trigger for germination and is a type of physiological dormancy. Most seeds are not affected by light or darkness, but many seeds, including species found in forest settings, will not germinate until an opening in the canopy allows sufficient light for growth of the seedling.
Scarification
Any process of breaking, scratching, or altering the seed coat through chemical or thermal methods, such as freezing over winter, may be necessary to make it permeable to water and gases. This process is known as scarification. Some seeds have impermeable seed coats that prevent oxygen and water from entering the seed, causing a type of physical dormancy which is broken when the seed coat is worn away enough to allow gas exchange and water uptake from the environment. In nature, some seeds require particular conditions to germinate, such as the heat of a wildfire or soaking in a body of water for a long period of time. Others need to be passed through a bird or animal's digestive tract to weaken the seed coat enough to allow the embryonic tree to emerge.
For mechanical scarification, seed coats can be scratched with a metal file, rubbed with sandpaper, nicked with a knife, or cracked gently with a hammer to weaken the seed coat. Scarification of seeds can also be achieved by imbibing them in concentrated sulfuric acid at appropriate concentrations and durations of treatment. Another scarification method involves the use of hot water for brief periods. Scarified seeds should be planted as soon as possible after treatment as they do not store well.
Breaking Dormancy
Some live seeds are dormant and need more time, and/or need to be subjected to specific environmental conditions before they will germinate. Seed dormancy can originate in different parts of the seed. Dormancy breaking often involves changes in membranes, initiated by certain hormones, notably gibberellin, which ends seed dormancy.
Roots
First to emerge from the seed coat is the primary root, or radicle as it is called in the embryo. This radicle is composed of one major root that is thicker at its base and tapers down toward the growing tip. Early root growth is one of the functions of the apical meristem located near the tip of the root. The meristem cells more or less continuously divide, producing more meristem, root cap cells (these are sacrificed to protect the meristem), and undifferentiated root cells. The latter become the primary tissues of the root, first undergoing elongation, a process that pushes the root tip forward in the growing medium. Gradually these cells differentiate and mature into specialized cells of the root tissues.
After the embryonic seedling emerges from the seed coat and starts growing roots and leaves, the embryonic seedling's food reserves are quickly exhausted. At this point, photosynthesis provides the energy needed for continued growth and the seedling now requires a continuous supply of water, nutrients, and light. Most tree species grow a taproot from the seed until moisture or an obstacle is reached, and the seedling can then focus on spreading structural roots and manufacturing food.
Tree roots will generally grow in any direction where the correct environment of air, mineral nutrients and water exists to meet the tree's needs. Roots will shrink away from dry, or other poor soil conditions.
Source
- Pittenger, Dennis R., California Master Gardener Handbook, University of California, Division of Agriculture and Natural Resources, ANR Publications, 2002.
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 .5 CEUs toward Certified Arborist, 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 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.
Soil Fungi
Edited by Len Phillips
Soil fungi are microscopic cells that grow in long threadlike structures or hyphae that make a mass called mycelium. The mycelium absorbs nutrients from the roots it has colonized along with surface organic matter and the soil. It produces special hyphae that create the reproductive spores. Fungi have many different structures but they can act in similar ways and thus are not as tree specific in their needs as soil bacteria.
Fungi groups
There are three functional groups of fungi.
1. Decomposers
Decomposers, or saprophytic fungi, convert dead organic matter into fungal biomass, carbon dioxide, and organic acids. They are essential for the decomposition of hard woody organic matter. By consuming the nutrients in the organic matter they play an important role in immobilizing and retaining nutrients in the soil. The organic acids they produce as by-products help create organic matter, which is resistant to degradation. Fungi are capable of degrading cellulose, proteins and lignin, some of which are highly resistant to breakdown.
2. Mutualists
Mutualist fungi develop mutually beneficial relationships with plants and trees. They colonize tree roots where they help the tree to obtain nutrients such as phosphorus from the soil. Their mass hides roots from pests and pathogens, and provides a greater root area through which the tree can obtain nutrients.
Mycorrhizal fungi
Mycorrhizal fungi are perhaps the best known of the mutualists. Mycorrhizae means fungus root, and mycorrhizal fungi grow inside tree roots. Up to 18 feet (5m) of living hyphae of mycorrhizal fungi can be extracted from 0.035 ounces (1g) of soil. The two groups of mycorrhizal fungi are arbuscular, and ecto-mycorrhizae. Arbuscular mycorrhizae are the most common form of mycorrhizae, especially in agricultural plant associations. This fungus has arbuscules, which are growths formed inside the plant root that have many small projections going into the cells. About 150 arbuscular mycorrhizae species are known. Most plants (90%) have some sort of association with these fungi except for groups such as the Cruciferae family (mustard, broccoli), Chenopodiaceae (spinach, beets) and Proteaceae (banksia, macadamia).
3. Pathogens
This group includes the well-known fungi such as Verticillium, Phytophthora, Rhizoctonia, and Pythium. These organisms penetrate the plant and decompose the living tissue, creating a weakened, nutrient deficient plant, or death. The pathogenic fungi are usually the dominant organism in the soil. Soils with high biodiversity have been shown to suppress soil-borne fungal diseases. Suppression mechanisms include the suite of native organisms out-competing the pathogenic organisms, physically protecting roots and providing better nutrition to the plant.
Function
Fungi perform important functions within the soil in relation to nutrient cycling; disease suppression, and water dynamics, all of which help plants become healthier and more vigorous. These functions include:
Fungi sources
Fungi are found wherever there is hard, carbon-rich woody organic matter. This could be dead rotting trees in a forest, leaf litter on the surface of soils, or plant roots.
Mycorrhizal fungi are found in all healthy soils. Techniques to determine their presence usually focus on indirect methods or looking at the colonization of plant roots, and are therefore not that reliable. It is difficult to get mycorrhizal fungi to grow outside their natural state, but staining techniques and microscopy have been useful in identifying mycorrhizae from soil and plant samples.
Fungi can survive in the soil for long periods even through periods of drought by living in dead plant roots and/or as spores or fragments of hyphae.
Management of soil fungi
There are several things that must be done to encourage fungi in the soil.
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 .5 CEUs toward Certified Arborist, 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 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
Soil fungi are microscopic cells that grow in long threadlike structures or hyphae that make a mass called mycelium. The mycelium absorbs nutrients from the roots it has colonized along with surface organic matter and the soil. It produces special hyphae that create the reproductive spores. Fungi have many different structures but they can act in similar ways and thus are not as tree specific in their needs as soil bacteria.
Fungi groups
There are three functional groups of fungi.
1. Decomposers
Decomposers, or saprophytic fungi, convert dead organic matter into fungal biomass, carbon dioxide, and organic acids. They are essential for the decomposition of hard woody organic matter. By consuming the nutrients in the organic matter they play an important role in immobilizing and retaining nutrients in the soil. The organic acids they produce as by-products help create organic matter, which is resistant to degradation. Fungi are capable of degrading cellulose, proteins and lignin, some of which are highly resistant to breakdown.
2. Mutualists
Mutualist fungi develop mutually beneficial relationships with plants and trees. They colonize tree roots where they help the tree to obtain nutrients such as phosphorus from the soil. Their mass hides roots from pests and pathogens, and provides a greater root area through which the tree can obtain nutrients.
Mycorrhizal fungi
Mycorrhizal fungi are perhaps the best known of the mutualists. Mycorrhizae means fungus root, and mycorrhizal fungi grow inside tree roots. Up to 18 feet (5m) of living hyphae of mycorrhizal fungi can be extracted from 0.035 ounces (1g) of soil. The two groups of mycorrhizal fungi are arbuscular, and ecto-mycorrhizae. Arbuscular mycorrhizae are the most common form of mycorrhizae, especially in agricultural plant associations. This fungus has arbuscules, which are growths formed inside the plant root that have many small projections going into the cells. About 150 arbuscular mycorrhizae species are known. Most plants (90%) have some sort of association with these fungi except for groups such as the Cruciferae family (mustard, broccoli), Chenopodiaceae (spinach, beets) and Proteaceae (banksia, macadamia).
3. Pathogens
This group includes the well-known fungi such as Verticillium, Phytophthora, Rhizoctonia, and Pythium. These organisms penetrate the plant and decompose the living tissue, creating a weakened, nutrient deficient plant, or death. The pathogenic fungi are usually the dominant organism in the soil. Soils with high biodiversity have been shown to suppress soil-borne fungal diseases. Suppression mechanisms include the suite of native organisms out-competing the pathogenic organisms, physically protecting roots and providing better nutrition to the plant.
Function
Fungi perform important functions within the soil in relation to nutrient cycling; disease suppression, and water dynamics, all of which help plants become healthier and more vigorous. These functions include:
- Decompose woody organic matter – Along with bacteria, fungi are important decomposers of hard to digest organic matter. They use nitrogen in the soil to decompose woody carbon rich residues low in nitrogen and convert the nutrients in the residues to forms that are more accessible for other organisms.
- Increase nutrient uptake – Mycorrhizal fungi are well known for their role in assisting plants in the uptake of phosphorus. Ecto-mycorrhizal fungi can benefit plants by promoting root branching and increasing nitrogen, phosphorus and water uptake due to their large surface area and internal cellular mechanisms.
- Improve plant resilience – The sheer size and mass of fungal hyphae help decrease plant susceptibility to pests, diseases and drought.
- Improve soil structure – Fungal hyphae bind the soil particles together to create water-stable aggregates which in turn create the pore spaces in the soil that enhance water retention and drainage.
Fungi sources
Fungi are found wherever there is hard, carbon-rich woody organic matter. This could be dead rotting trees in a forest, leaf litter on the surface of soils, or plant roots.
Mycorrhizal fungi are found in all healthy soils. Techniques to determine their presence usually focus on indirect methods or looking at the colonization of plant roots, and are therefore not that reliable. It is difficult to get mycorrhizal fungi to grow outside their natural state, but staining techniques and microscopy have been useful in identifying mycorrhizae from soil and plant samples.
Fungi can survive in the soil for long periods even through periods of drought by living in dead plant roots and/or as spores or fragments of hyphae.
Management of soil fungi
There are several things that must be done to encourage fungi in the soil.
- Provide a hospitable environment – To ensure fungi remain in the earth; the soil environment must be kept as hospitable as possible. This means there must be enough organic matter, suitable host plants, water, and minimal disturbance of the soil.
- Reduce tillage – Tillage has a disastrous effect on fungi as it physically severs the hyphae and breaks up the mycelium.
- Reduce fungicide use – Broad-spectrum fungicides are toxic to a wide range of fungi. Their use will result in a decline in the numbers of beneficial types. Herbicides are not generally thought to affect fungi directly, though the removal of some plant types may affect the distribution of different fungi types.
- Grow plants that encourage mycorrhizal fungi – There are certain plant groups that do not form associations with mycorrhizal fungi. When these plants are included in a landscape planting, fungi numbers drop due to the lack of host plants and this reduces fungi colonization in nearby plants.
- Jenkins, Abigai, “Soil fungi”, State of New South Wales, Department of Primary Industries, 2005.
- Phillips, Len, “All About Root Development”, Online Seminars for Municipal Arborists, 2013.
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 .5 CEUs toward Certified Arborist, 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 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 Riparian Forest Buffers
by Richard H. Miller
An urban riparian buffer is the area where the land has an effect on the water and the water has an effect on the land. It is basically where trees and shrubs grow on the water's edge. Urban riparian buffer widths are important for stream diversity and the protection of the stream’s ecosystem.
On a local scale, the riparian forest may regulate stream width and form, as well as seasonal water temperature and the energy base. While riparian cover has the most impact in the headwater areas, it serves a purpose downstream as well by providing localized habitats, shade, aesthetics, and to some extent, a sound barrier.
Riparian Forest Health
Small streams with a healthy riparian forest are more likely to contain needed subsurface shade in the form of woody aquatic debris. In the good riparian areas one can forget where they are and they do not hear (or at least mentally close out) the harsh sounds of the nearby city. In most cases though, man’s physical and visual impacts, including canopy removal, may overwhelm the capacity of riparian areas to provide buffer effects for stream fauna. In fact, much of the suspended solids and pollutants in streams following storm events may arise from within the stream bed as well as from sheet erosion. Drainage system discharges due to mans’ influences may make natural erosive forces much worse.
Hydraulic alterations to a watershed may overwhelm most influences that local urban riparian forests have on stream life. Conversely, viewing aerial photos of a less urbanized stream, the Stillwater River, in western Ohio’s corn-belt has its’ riparian zones virtually unbroken. The Stillwater River stream health is good and fishing can be exceptional on this shaded rural fishery.
Fish Populations
On the subject of fish populations, pools and open bank areas support numerous tolerant fish species. Streams containing woody debris and associated riparian vegetation support the more desirable sensitive fish species. Relative to sport fishing success, when I go fishing along Walnut Creek in populated central Ohio, I generally don’t catch the desirable sport fish in the pools along open banks with sparse underwater woody debris.
According to one researcher urban stream buffers are less important to fish richness because:
Ecologists have shown that the number of endemic and sensitive fish species found in many urban streams are best predicted by the amount of forest cover and the amount of urban-impervious surfaces within the catchment area. An abundance of sensitive species exhibit a striking response to the amount of forest in the riparian network, with virtually no sensitive species found at sites with less than 70% forest.
Riparian Health and Water Quality
Additionally, research shows that the riparian cover in the upstream network is important for maintaining sensitive fishes, while local reductions in riparian forest cover increase tolerant fishes.
This is not to say that riparian vegetation in urban sites is necessary for riparian health and water quality. Overreaching influences of impervious surfaces, field drains, storm water pipes in urban reaches, and rural catchments drastically affect aquatic systems via non-point-source impairment.
Pristine Streams
Pristine streams have not been experienced by any living person and may not be practical to envision a return to such a complex environment. Even at modest levels of disturbance, deforestation, and the conversion to agriculture, urbanization, and other disturbances have detrimental effects on streams.
We have destroyed the natural systems that maintain the watershed. No pollutants appear to have had a more universal or lasting adverse effect upon aquatic life since the first settlers in 1800 than have the original clays and silts. Plowing the land following the removal of trees increases the erosion of glacial silts and clays also causing adverse effects to the pristine streams.
In addition, stream bank erosion can be viewed only as a problem if it affects man and mans’ vision of what a stream should be. Stream banks have been eroding and rebuilding at least since glacial times, 10,000 years ago. Stream bank erosion only occurs within the meander pattern of the stream valley. Stream dynamics necessitate knowledge of erosive forces that define stream meander width, structure, and health. Historically, with few exceptions, the streams in the Ohio country usually were devoid of clayey silts, even during floods, and the waters were very transparent or clear, which the pioneers referred to as “fair water,” until at least 1850, when “dirty” or turbid waters began to be mentioned increasingly. Presently we clearly view riparian vegetation as holding stream banks in place albeit in a degraded wider, shallower, and more linear state than before European settlement.
The Future
Shaded streams, especially headwater areas, are kept cooler in summer by riparian vegetation and definitely have effects on headwater systems. In fact climatologists are concerned that many fish species will not survive to the end of this century because of climate change and its effect on aquatic environments. Hypothetically as stream temperatures warm, tolerant species will dominate and species richness will decline. Headwater riparian forests will prove to be critical to small steam life. Local urban riparian forests are necessary but may not critically control biotic integrity in eastern urban streams due to upstream influences. In the extreme view, man-altered linear streams such as those enclosed by concrete banks are not as pleasing as pristine and sinuous tree lined environs and will not be as diverse. Realistically viewed, the pristine will support a richer diversity of life and instill a sense of place regardless of the challenges of catchment restoration to mimic a natural pre-disturbance hydrology and canopy to watersheds including opinions of essential widths of urban riparian areas.
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 .5 CEUs toward Certified Arborist 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 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 Richard H. Miller
An urban riparian buffer is the area where the land has an effect on the water and the water has an effect on the land. It is basically where trees and shrubs grow on the water's edge. Urban riparian buffer widths are important for stream diversity and the protection of the stream’s ecosystem.
On a local scale, the riparian forest may regulate stream width and form, as well as seasonal water temperature and the energy base. While riparian cover has the most impact in the headwater areas, it serves a purpose downstream as well by providing localized habitats, shade, aesthetics, and to some extent, a sound barrier.
Riparian Forest Health
Small streams with a healthy riparian forest are more likely to contain needed subsurface shade in the form of woody aquatic debris. In the good riparian areas one can forget where they are and they do not hear (or at least mentally close out) the harsh sounds of the nearby city. In most cases though, man’s physical and visual impacts, including canopy removal, may overwhelm the capacity of riparian areas to provide buffer effects for stream fauna. In fact, much of the suspended solids and pollutants in streams following storm events may arise from within the stream bed as well as from sheet erosion. Drainage system discharges due to mans’ influences may make natural erosive forces much worse.
Hydraulic alterations to a watershed may overwhelm most influences that local urban riparian forests have on stream life. Conversely, viewing aerial photos of a less urbanized stream, the Stillwater River, in western Ohio’s corn-belt has its’ riparian zones virtually unbroken. The Stillwater River stream health is good and fishing can be exceptional on this shaded rural fishery.
Fish Populations
On the subject of fish populations, pools and open bank areas support numerous tolerant fish species. Streams containing woody debris and associated riparian vegetation support the more desirable sensitive fish species. Relative to sport fishing success, when I go fishing along Walnut Creek in populated central Ohio, I generally don’t catch the desirable sport fish in the pools along open banks with sparse underwater woody debris.
According to one researcher urban stream buffers are less important to fish richness because:
- they are often by-passed,
- the impacts of watershed land use overwhelms the capacity of riparian zones to buffer a stream's eco-system,
- discontinuous riparian buffers will not settle water quality problems because transport through perennial vegetation gaps (agriculture) dominate the discharge in addition to reduced canopy, direct storm sewer discharges, and impervious urban landscapes
- hydraulic alteration overwhelms any influence of riparian forests on stream biota.
Ecologists have shown that the number of endemic and sensitive fish species found in many urban streams are best predicted by the amount of forest cover and the amount of urban-impervious surfaces within the catchment area. An abundance of sensitive species exhibit a striking response to the amount of forest in the riparian network, with virtually no sensitive species found at sites with less than 70% forest.
Riparian Health and Water Quality
Additionally, research shows that the riparian cover in the upstream network is important for maintaining sensitive fishes, while local reductions in riparian forest cover increase tolerant fishes.
This is not to say that riparian vegetation in urban sites is necessary for riparian health and water quality. Overreaching influences of impervious surfaces, field drains, storm water pipes in urban reaches, and rural catchments drastically affect aquatic systems via non-point-source impairment.
Pristine Streams
Pristine streams have not been experienced by any living person and may not be practical to envision a return to such a complex environment. Even at modest levels of disturbance, deforestation, and the conversion to agriculture, urbanization, and other disturbances have detrimental effects on streams.
We have destroyed the natural systems that maintain the watershed. No pollutants appear to have had a more universal or lasting adverse effect upon aquatic life since the first settlers in 1800 than have the original clays and silts. Plowing the land following the removal of trees increases the erosion of glacial silts and clays also causing adverse effects to the pristine streams.
In addition, stream bank erosion can be viewed only as a problem if it affects man and mans’ vision of what a stream should be. Stream banks have been eroding and rebuilding at least since glacial times, 10,000 years ago. Stream bank erosion only occurs within the meander pattern of the stream valley. Stream dynamics necessitate knowledge of erosive forces that define stream meander width, structure, and health. Historically, with few exceptions, the streams in the Ohio country usually were devoid of clayey silts, even during floods, and the waters were very transparent or clear, which the pioneers referred to as “fair water,” until at least 1850, when “dirty” or turbid waters began to be mentioned increasingly. Presently we clearly view riparian vegetation as holding stream banks in place albeit in a degraded wider, shallower, and more linear state than before European settlement.
The Future
Shaded streams, especially headwater areas, are kept cooler in summer by riparian vegetation and definitely have effects on headwater systems. In fact climatologists are concerned that many fish species will not survive to the end of this century because of climate change and its effect on aquatic environments. Hypothetically as stream temperatures warm, tolerant species will dominate and species richness will decline. Headwater riparian forests will prove to be critical to small steam life. Local urban riparian forests are necessary but may not critically control biotic integrity in eastern urban streams due to upstream influences. In the extreme view, man-altered linear streams such as those enclosed by concrete banks are not as pleasing as pristine and sinuous tree lined environs and will not be as diverse. Realistically viewed, the pristine will support a richer diversity of life and instill a sense of place regardless of the challenges of catchment restoration to mimic a natural pre-disturbance hydrology and canopy to watersheds including opinions of essential widths of urban riparian areas.
Sources
- Farst S., Unpublished abstract, EMH&T Engineers, Ohio Statewide Floodplain Management Conference, 2012.
- Ohio EPA ,”TMDL for the Walnut Creek Watershed”, (2.3 pg. 8), 2006.
- Roy, A.H., “Can riparian forests mediate Impacts of urbanization on stream fish assemblages?”, Pg. 1-80, 2004.
- Trautman, M.B., “The Ohio Country From 1750 to 1977 A Naturalist’s View”, The Ohio State University, Pg. 1-9, 1977.
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 .5 CEUs toward Certified Arborist 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 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.
Cultivars of Japanese Tree Lilac
Edited by Len Phillips
The Japanese Tree Lilac is more important for its beautiful form than its not-so-fragrant flower. The description that follows provides a summary of similarities that all the cultivars possess. This information has been gathered from personal observations of the author, living in Massachusetts, Zone 6, and information provided by J. Frank Schmidt & Son.
Botanical Name: Syringa reticulata
Common Name: Japanese Tree Lilac
Hardiness Zone: 3 – 8
Habitat: Species introduced from Japan in 1876
Flower: Large creamy white clusters 6" - 12" long, begin flowering at an early age, mid June to July bloom, penetrating fragrance like privet, not like the common lilac, spent flowers are considered unsightly by some and winter interest by others
Fruit: Dry capsule, ¾ inch long
Bark: Bark similar to cherry, reddish brown with horizontal lenticels
Winter Color: Cherry-like bark plus persistent brown capsules provide winter interest
Growth Rate: Medium, 25' high and 15' wide after 30 years
Planting: Transplants easily by bare root and B&B, well-suited for CU-Structural Soil planting
Culture: Full sun is best, flower quantity is greatly diminished in partial shade, pH 6.5 – 8, well drained soil, prefers cool summers
Pruning: Prune at planting and 3 years later to mature form
Propagation: Cultivars are not true from seed, must be budded onto Syringa reticulata seedlings or by softwood cuttings
Site Requirements: Medium loam, moist, well drained, sun, adapts to all pH, tolerates pollution, drought, wind, and shade
Pest and Disease Resistance: Highly resistant to Dutch elm disease and Elm beetles as well as the Japanese beetle
Salt Resistance: Good to excellent
Storm Resistance: Narrow crotch angles on some cultivars can split in storms
Design Uses: Good street tree for under wires, excellent specimen for residential landscapes as a single tree or in groups
Companions: Use with Phlox subulata ground cover
Other Comments: Medium texture in all seasons, uniform shape,
Of the dozen cultivars and closely related subspecies, the seven listed below are considered by this author to be the best of them, although three of them are very hard to find in nurseries today.
Beijing Gold® Lilac Syringa pekinensis ‘Zhang Zhiming’ – Height: 20'; Spread: 20'; Shape: upright spreading; Foliage: dark green; Fall Color: yellowish; Flower: yellow, in clusters. Sprays of yellow flowers borne in June bring a whole new color spectrum to the world of tree lilacs. This is a vigorous selection with upright spreading, arching branches in a species that matures to a small size. Fact Sheet
Chantilly Lace Tree Lilac Syringa pekinensis ‘Chantilly Lace’ – Height: 20'; Spread: 20'; Foliage: irregular margins on young leaves are pale yellow, maturing to creamy yellow. Leaves may burn in hot locations so tree is no longer popular. This Herrmann Nursery introduction from Limehouse, Ontario is hard to find in the nursery trade.
China Snow® Tree Lilac Syringa pekinensis ‘Morton’ – Height: 20', Spread: 20', Shape: upright tree. Amber to orange-brown exfoliating bark is outstanding and extends seasonal interest through the winter months. Fact Sheet
Ivory Silk® Tree Lilac Syringa reticulata ‘Ivory Silk’ – Plant Patent #7205 – Height: 20’-25’, Spread: 15’ – 20'’, Shape: sturdy, compact, oval growth habit; Foliage: blue green in summer, autumn color is sometimes green with reddish band on leaf margin; Flower: creamy white panicles. Large plumes of small white flowers smother its branches in early summer. This straight trunked selection was found by Sheridan Nursery in 1975. Resistant to borer, scale, and mildew, it is the most trouble free lilac. It was selected by the Society of Municipal Arborists as the 1997 Urban Tree of the Year. Fact Sheet
Regent Tree Lilac Syringa pekinensis ‘Regent’ – Height: 20', Spread: 20', Shape: Upright tree. This Princeton Nursery introduction is limited in its availability.
Summer Charm® Tree Lilac Syringa pekinensis ‘DTR 124’ PP 8951 – Height: 20’; Spread: 15’, Shape: upright, spreading, Foliage: dark green, glossy, Fall Color: yellow, Flower: creamy white panicles. Finer textured and more relaxed in appearance than Japanese tree lilac, it features lustrous foliage and abundant flowers. Fact Sheet
Summer Snow Tree Lilac Syringa pekinensis ‘Summer Snow’ – Height: 20’, Spread: 15’, Shape: compact, rounded form, Flower: profuse large panicles of fragrant, creamy white flowers. Glossy, cherry-like bark makes a handsome addition on a small street or lawn. This Schichtel Nursery introduction may be hard to find. Fact Sheet
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 .5 CEUs toward Certified Arborist, Utility Specialist, Municipal Specialist, Tree Worker Specialist, Aerial Lift 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 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 Japanese Tree Lilac is more important for its beautiful form than its not-so-fragrant flower. The description that follows provides a summary of similarities that all the cultivars possess. This information has been gathered from personal observations of the author, living in Massachusetts, Zone 6, and information provided by J. Frank Schmidt & Son.
Botanical Name: Syringa reticulata
Common Name: Japanese Tree Lilac
Hardiness Zone: 3 – 8
Habitat: Species introduced from Japan in 1876
Flower: Large creamy white clusters 6" - 12" long, begin flowering at an early age, mid June to July bloom, penetrating fragrance like privet, not like the common lilac, spent flowers are considered unsightly by some and winter interest by others
Fruit: Dry capsule, ¾ inch long
Bark: Bark similar to cherry, reddish brown with horizontal lenticels
Winter Color: Cherry-like bark plus persistent brown capsules provide winter interest
Growth Rate: Medium, 25' high and 15' wide after 30 years
Planting: Transplants easily by bare root and B&B, well-suited for CU-Structural Soil planting
Culture: Full sun is best, flower quantity is greatly diminished in partial shade, pH 6.5 – 8, well drained soil, prefers cool summers
Pruning: Prune at planting and 3 years later to mature form
Propagation: Cultivars are not true from seed, must be budded onto Syringa reticulata seedlings or by softwood cuttings
Site Requirements: Medium loam, moist, well drained, sun, adapts to all pH, tolerates pollution, drought, wind, and shade
Pest and Disease Resistance: Highly resistant to Dutch elm disease and Elm beetles as well as the Japanese beetle
Salt Resistance: Good to excellent
Storm Resistance: Narrow crotch angles on some cultivars can split in storms
Design Uses: Good street tree for under wires, excellent specimen for residential landscapes as a single tree or in groups
Companions: Use with Phlox subulata ground cover
Other Comments: Medium texture in all seasons, uniform shape,
Of the dozen cultivars and closely related subspecies, the seven listed below are considered by this author to be the best of them, although three of them are very hard to find in nurseries today.
Beijing Gold® Lilac Syringa pekinensis ‘Zhang Zhiming’ – Height: 20'; Spread: 20'; Shape: upright spreading; Foliage: dark green; Fall Color: yellowish; Flower: yellow, in clusters. Sprays of yellow flowers borne in June bring a whole new color spectrum to the world of tree lilacs. This is a vigorous selection with upright spreading, arching branches in a species that matures to a small size. Fact Sheet
Chantilly Lace Tree Lilac Syringa pekinensis ‘Chantilly Lace’ – Height: 20'; Spread: 20'; Foliage: irregular margins on young leaves are pale yellow, maturing to creamy yellow. Leaves may burn in hot locations so tree is no longer popular. This Herrmann Nursery introduction from Limehouse, Ontario is hard to find in the nursery trade.
China Snow® Tree Lilac Syringa pekinensis ‘Morton’ – Height: 20', Spread: 20', Shape: upright tree. Amber to orange-brown exfoliating bark is outstanding and extends seasonal interest through the winter months. Fact Sheet
Ivory Silk® Tree Lilac Syringa reticulata ‘Ivory Silk’ – Plant Patent #7205 – Height: 20’-25’, Spread: 15’ – 20'’, Shape: sturdy, compact, oval growth habit; Foliage: blue green in summer, autumn color is sometimes green with reddish band on leaf margin; Flower: creamy white panicles. Large plumes of small white flowers smother its branches in early summer. This straight trunked selection was found by Sheridan Nursery in 1975. Resistant to borer, scale, and mildew, it is the most trouble free lilac. It was selected by the Society of Municipal Arborists as the 1997 Urban Tree of the Year. Fact Sheet
Regent Tree Lilac Syringa pekinensis ‘Regent’ – Height: 20', Spread: 20', Shape: Upright tree. This Princeton Nursery introduction is limited in its availability.
Summer Charm® Tree Lilac Syringa pekinensis ‘DTR 124’ PP 8951 – Height: 20’; Spread: 15’, Shape: upright, spreading, Foliage: dark green, glossy, Fall Color: yellow, Flower: creamy white panicles. Finer textured and more relaxed in appearance than Japanese tree lilac, it features lustrous foliage and abundant flowers. Fact Sheet
Summer Snow Tree Lilac Syringa pekinensis ‘Summer Snow’ – Height: 20’, Spread: 15’, Shape: compact, rounded form, Flower: profuse large panicles of fragrant, creamy white flowers. Glossy, cherry-like bark makes a handsome addition on a small street or lawn. This Schichtel Nursery introduction may be hard to find. Fact Sheet
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 .5 CEUs toward Certified Arborist, Utility Specialist, Municipal Specialist, Tree Worker Specialist, Aerial Lift 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 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.
Research Briefs 56
Edited by Len Phillips
Physics Limits Tree Size
Maciej Zwieniecki and Kaare Jensen
Basic scientific principles are at work in nature. This study measured the size of leaves on trees and how tall the trees have grown. Leaf size and tree height are determined by the physics of the tree’s vascular system that nourishes the tree from leaf to trunk for the optimal flow of sap and energy throughout the tree. This study provided a new explanation for the lack of tall trees in environments with limited water and the prevalence of the tallest trees to grow in the world’s most forgiving environments, such as tropical rain forests or foggy river ravines.
The researchers focused on angiosperms, the group of flowering plants that includes trees like oak and sycamore, rather than on the gymnosperm group, which includes trees like pine and spruce. In analyzing data on 1,925 angiosperm tree species, they found that tree leaves range in size from less than one inch to more than four feet long (2.5 to 120 cm). Among the tallest of the trees, however, leaves range from approximately 4 inches to 8 inches (10 to 20 cm) long. The decline in leaf size diversity that accompanies increasing tree height is a product of fluid dynamics within the tree. The sugar-rich fluid produced through photosynthesis in the leaves travels to other parts of the tree via phloem cells. As the fluid passed through the leaf phloem toward the stem, it gathers speed as more and more water was pulled in from the leaf through osmosis. Consequently, the longer the leaf, the faster the fluid flowed. When the fluid reached the tree trunk, however, no more sugar was collected in the phloem, and only water was drawn from the surrounding tissue. The trunk phloem was longer and consequently, presented more resistance to the fluid’s flow as it traveled down the trunk to the roots.
This fact illustrates two functions at work, one involving leaf size and the other related to tree height.
1. First, there was an advantage for a tree to have larger leaves because it could produce more nutrient-rich fluid that would flow more quickly toward the trunk and roots. If the tree’s leaves were too small, the fluid would move too slowly to be beneficial.
2. Secondly, although increased height might provide some trees with better access to sunlight, it also would increase the length and thus flow resistance of the trunk phloem, slowing the movement of nutrients toward the roots.
So there comes a point where the optimal limits on leaf size and tree height intersect, indicating the point at which it is no longer advantageous for the tree to become taller or produce larger leaves. This point is approximately 100 meters, or slightly more than 300 feet which is about the size of the tallest angiosperms.
Physical Review Letters, UC Davis News and Information, January 2013.
Older Trees Grow Faster as They Age
Nate Stephenson
Instead of slowing down as the centuries add up, old trees speed up their growth. One finding, published in 2010, revealed California's towering coast redwoods keep racing skyward throughout their several-thousand-year life span. At a recent gathering of forestry experts from six continents, researchers looked at more than 670,000 tropical and temperate trees and 403 tree species. They found that for more than 90% of the species, the trees kept growing in trunk diameter throughout their entire life span, gaining mass as the years progressed. Each species grows at its own rate, but the biggest, oldest trees can swell their wood, bark, and leaf mass by 1,300 lbs. (about 600 kilograms) in one year. Trees seem free from any growth limit, called senescence. Instead, only logging, disease, insects, fire, or accidents will kill a tree. They never stop growing. Every year they are always putting on more weight and diameter than before.
Animals and humans start growing slowly, then reach adolescence and have a growth spurt, then slow down again. Cells change and break down over a lifetime eventually causing death. But as the new findings show, trees reach that adolescent growth spurt but never stop.
Former Research
It had always been suspected, but never proven, that older trees grow more slowly than young trees. The evidence came from measuring carbon trapped by forests. Overall, a forest full of young trees sucked more carbon from the atmosphere than a same-sized acreage filled by elderly trees. So scientists assumed the older trees were growing more slowly, because they absorbed less carbon. But these early data were not measuring individual trees.
Nature, January 15, 2014
Effect of Transplanting Date and Harvest Method on Three Urban Trees
Nematollah Etemadi, Rezvan Mohammadi Nezhad, Najmeh Zamani, and Mohammad Mahdi Majidi
The major challenges for transplanting trees in arid regions compared to temperate regions are higher mortality and slower rate of establishment. As such, date and method of transplanting can potentially improve survival and establishment as well as subsequent landscape performance of transplanted trees in arid climates.
In this study, three urban species commonly grown include eldarica pine (Pinus eldarica), white mulberry (Morus alba), and smoothleaf elm (Ulmus carpinifolia). They were transplanted when mean air temperature was less than 10°C (50°F) (early winter), between 10°C and 20°C (50°F-70°F) (early spring), or more than 20°C (70°F) (late spring). Half of the trees were bare root (BR) and half balled and burlapped (B&B).
White mulberry and smoothleaf elm trees transplanted early in winter had the highest survival percentage over two years. The best survival for eldarica pine was observed in early spring transplanted trees. For all species, survival rate and trunk diameter increase of B&B trees were significantly greater than BR trees during the first year. Also, the first year’s shoot growth and shoot number of pine trees, and dieback on elm trees, were significantly affected by transplanting method.
During the second year, tree growth and survival for all species were similar for B&B and BR trees. Annual shoot growth of eldarica pine and smoothleaf elm trees, but not white mulberry, equaled to non-transplanted trees by the end of third year after transplanting. This suggests a species-specific response for post-transplant establishment in arid climate.
Arboriculture & Urban Forestry, 2013. 39(5): 211–217
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 .5 CEUs toward Certified Arborist, Utility Specialist, Municipal Specialist, Tree Worker Specialist, Aerial Lift 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 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
Physics Limits Tree Size
Maciej Zwieniecki and Kaare Jensen
Basic scientific principles are at work in nature. This study measured the size of leaves on trees and how tall the trees have grown. Leaf size and tree height are determined by the physics of the tree’s vascular system that nourishes the tree from leaf to trunk for the optimal flow of sap and energy throughout the tree. This study provided a new explanation for the lack of tall trees in environments with limited water and the prevalence of the tallest trees to grow in the world’s most forgiving environments, such as tropical rain forests or foggy river ravines.
The researchers focused on angiosperms, the group of flowering plants that includes trees like oak and sycamore, rather than on the gymnosperm group, which includes trees like pine and spruce. In analyzing data on 1,925 angiosperm tree species, they found that tree leaves range in size from less than one inch to more than four feet long (2.5 to 120 cm). Among the tallest of the trees, however, leaves range from approximately 4 inches to 8 inches (10 to 20 cm) long. The decline in leaf size diversity that accompanies increasing tree height is a product of fluid dynamics within the tree. The sugar-rich fluid produced through photosynthesis in the leaves travels to other parts of the tree via phloem cells. As the fluid passed through the leaf phloem toward the stem, it gathers speed as more and more water was pulled in from the leaf through osmosis. Consequently, the longer the leaf, the faster the fluid flowed. When the fluid reached the tree trunk, however, no more sugar was collected in the phloem, and only water was drawn from the surrounding tissue. The trunk phloem was longer and consequently, presented more resistance to the fluid’s flow as it traveled down the trunk to the roots.
This fact illustrates two functions at work, one involving leaf size and the other related to tree height.
1. First, there was an advantage for a tree to have larger leaves because it could produce more nutrient-rich fluid that would flow more quickly toward the trunk and roots. If the tree’s leaves were too small, the fluid would move too slowly to be beneficial.
2. Secondly, although increased height might provide some trees with better access to sunlight, it also would increase the length and thus flow resistance of the trunk phloem, slowing the movement of nutrients toward the roots.
So there comes a point where the optimal limits on leaf size and tree height intersect, indicating the point at which it is no longer advantageous for the tree to become taller or produce larger leaves. This point is approximately 100 meters, or slightly more than 300 feet which is about the size of the tallest angiosperms.
Physical Review Letters, UC Davis News and Information, January 2013.
Older Trees Grow Faster as They Age
Nate Stephenson
Instead of slowing down as the centuries add up, old trees speed up their growth. One finding, published in 2010, revealed California's towering coast redwoods keep racing skyward throughout their several-thousand-year life span. At a recent gathering of forestry experts from six continents, researchers looked at more than 670,000 tropical and temperate trees and 403 tree species. They found that for more than 90% of the species, the trees kept growing in trunk diameter throughout their entire life span, gaining mass as the years progressed. Each species grows at its own rate, but the biggest, oldest trees can swell their wood, bark, and leaf mass by 1,300 lbs. (about 600 kilograms) in one year. Trees seem free from any growth limit, called senescence. Instead, only logging, disease, insects, fire, or accidents will kill a tree. They never stop growing. Every year they are always putting on more weight and diameter than before.
Animals and humans start growing slowly, then reach adolescence and have a growth spurt, then slow down again. Cells change and break down over a lifetime eventually causing death. But as the new findings show, trees reach that adolescent growth spurt but never stop.
Former Research
It had always been suspected, but never proven, that older trees grow more slowly than young trees. The evidence came from measuring carbon trapped by forests. Overall, a forest full of young trees sucked more carbon from the atmosphere than a same-sized acreage filled by elderly trees. So scientists assumed the older trees were growing more slowly, because they absorbed less carbon. But these early data were not measuring individual trees.
Nature, January 15, 2014
Effect of Transplanting Date and Harvest Method on Three Urban Trees
Nematollah Etemadi, Rezvan Mohammadi Nezhad, Najmeh Zamani, and Mohammad Mahdi Majidi
The major challenges for transplanting trees in arid regions compared to temperate regions are higher mortality and slower rate of establishment. As such, date and method of transplanting can potentially improve survival and establishment as well as subsequent landscape performance of transplanted trees in arid climates.
In this study, three urban species commonly grown include eldarica pine (Pinus eldarica), white mulberry (Morus alba), and smoothleaf elm (Ulmus carpinifolia). They were transplanted when mean air temperature was less than 10°C (50°F) (early winter), between 10°C and 20°C (50°F-70°F) (early spring), or more than 20°C (70°F) (late spring). Half of the trees were bare root (BR) and half balled and burlapped (B&B).
White mulberry and smoothleaf elm trees transplanted early in winter had the highest survival percentage over two years. The best survival for eldarica pine was observed in early spring transplanted trees. For all species, survival rate and trunk diameter increase of B&B trees were significantly greater than BR trees during the first year. Also, the first year’s shoot growth and shoot number of pine trees, and dieback on elm trees, were significantly affected by transplanting method.
During the second year, tree growth and survival for all species were similar for B&B and BR trees. Annual shoot growth of eldarica pine and smoothleaf elm trees, but not white mulberry, equaled to non-transplanted trees by the end of third year after transplanting. This suggests a species-specific response for post-transplant establishment in arid climate.
Arboriculture & Urban Forestry, 2013. 39(5): 211–217
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 .5 CEUs toward Certified Arborist, Utility Specialist, Municipal Specialist, Tree Worker Specialist, Aerial Lift 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 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.