Archive #57 from Online Seminars for Municipal Arborists – July/August 2014
Sections Click on the green words for more information
Canopy Pruning, Yes or No?
Edited by Len Phillips
Remember the old days when conventional wisdom said tree canopies should be pruned to remove one-third at planting time to compensate for the root loss? The tree’s root system was reduced in size because they were being dug up to be balled and burlapped or for a tree spade move. For many years, compensatory pruning was considered the best way to balance the natural root to crown ratio. Removing one-third of the canopy was thought to increase transplant survival and decrease canopy dieback because trees would be healthier and not straining to support a mass of leaves with limited roots. Removing these branches at planting time just seemed logical. As reasonable as this practice seemed, a scientific base to support this concept never existed. Did you know this was changed because of an accident?
It all began in the 1970's, at a nursery in Oklahoma. A research team led by Dr. Carl Whitcomb was conducting a weed control study. As part of the research plan, tree canopies were pruned back at transplanting, since this was the standard practice that every respectable arborist and horticulturist would follow. However, Mother Nature intervened and a long rainy spring season prevented the compensatory pruning in 40% of the trees. By the time the nursery fields dried and workers could resume work, the trees had started their flush of spring growth. It was decided not to prune the remaining unpruned trees. During the first growing season a fortuitous finding occurred. The unpruned trees grew faster and had fewer failures than the pruned trees.
But perhaps these observations were merely due to species differences. Follow-up experiments were conducted to confirm the earlier findings that compensatory pruning was truly non-beneficial. In a total of 11 different species, subsets of trees were either pruned or not pruned to remove 15%, 30% or 45% of the canopy. Each treatment was replicated 12 times and tree responses were evaluated for two years. Again, compensatory pruning was found to be non-beneficial. Since then, three additional studies in other locations (Colorado and England) by different research teams have produced similar results.
Water Limitations
The findings in England were interesting because they suggested pruning to compensate for root loss was not the critical question; rather that soil moisture was more important. When pruned or unpruned treatments were grown in a dry soil condition they both grew very little. But when water was not a limiting factor, pruned trees had less root growth, as well as fewer, and smaller leaves. Trees not pruned at planting that received ample water had more leaf tissue to photosynthesize and a greater ability to produce tree growth.
Water Guidelines
In addition to not performing compensatory pruning, what else could be done to decrease canopy dieback, increase transplant survival, and improve tree health? The conventional tree-watering guide at that time suggested 1 – 1.5 inches (2.5 – 3.8 cm) of rain or irrigation water every seven to ten days is appropriate. Apparently this common watering guideline was always accepted as fact and never researched. Now, in recent years, the Morton Arboretum and the University of Florida have produced research that suggests more frequent watering is optimal. These results determined that newly transplanted trees benefit from:
1. daily watering for the first one to two weeks, applying approximately 1.5 gallons per caliper inch (1.5 liters per caliper centimeter) per watering,
2. after two weeks, water the trees every two to three days for the next two or three months, with approximately 1.5 gallons per caliper inch (1.5 liters per caliper cm)
3. after 2-3 months, weekly watering is necessary for the remainder of the season or until the tree is established.
4. after the first year, if watering is necessary, it should be 1 gallon of water per inch of caliper. This equates to 1 inch of rainfall per week.
Newly transplanted trees are absorbing water from a diminished rooting area, so apply all the water to the root ball area. Roots must generate and grow into surrounding soils before a larger soil volume can be tapped for moisture. When tree roots have spread into the surrounding soil, they are considered established.
Trees in northern climates will become established within one to one-and-a-half years for each caliper inch (2.5 cm) of stem. Therefore, it takes two to three years before a two-inch (5 cm) caliper tree becomes established. If you cannot adequately meet the water requirements of newly transplanted trees, planting smaller trees is recommended. For example, one inch (2.5 cm) caliper trees have less root loss and recover faster (1 year) than trees with two to three inches (5 – 7.5 cm) in stem caliper. Also keep in mind that mulching trees with a two to three-inch (5 – 7.5 cm) depth is recommended as it helps to conserve water.
Branch Removal at Planting
On the other hand, even though compensatory pruning is not recommended, some branches may require removal and most nurseries prune out co-dominant leaders, limbs that rub against each other, and poorly angled branches, long before the sale. If a problem has not been pruned in the nursery, remove it after planting. All trees should be inspected because some limbs may have been damaged in transit from the nursery to the planting site. Also, any dead, dying, and diseased branches should be removed.
Branches that are weakly attached or have included bark should be removed at planting, unless you can revisit the tree and prune it within the next few years. If removing these bad branches will result in more than 10% to 20% canopy loss, do not accept the tree. If your supplier has many trees that require extensive pruning, it may be best to either look for a new supplier of nursery stock or discuss quality issues with this supplier. Arborists often forget that as buyers we can influence the quality of nursery stock. Accepting inferior stock only perpetuates more of it entering the market.
Selecting structurally sound and healthy trees are a must. Whitcomb said it best 45 years ago: “Top pruning and other practices are unlikely to help an unthrifty tree and a thrifty tree doesn’t need it.”
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, 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
Remember the old days when conventional wisdom said tree canopies should be pruned to remove one-third at planting time to compensate for the root loss? The tree’s root system was reduced in size because they were being dug up to be balled and burlapped or for a tree spade move. For many years, compensatory pruning was considered the best way to balance the natural root to crown ratio. Removing one-third of the canopy was thought to increase transplant survival and decrease canopy dieback because trees would be healthier and not straining to support a mass of leaves with limited roots. Removing these branches at planting time just seemed logical. As reasonable as this practice seemed, a scientific base to support this concept never existed. Did you know this was changed because of an accident?
It all began in the 1970's, at a nursery in Oklahoma. A research team led by Dr. Carl Whitcomb was conducting a weed control study. As part of the research plan, tree canopies were pruned back at transplanting, since this was the standard practice that every respectable arborist and horticulturist would follow. However, Mother Nature intervened and a long rainy spring season prevented the compensatory pruning in 40% of the trees. By the time the nursery fields dried and workers could resume work, the trees had started their flush of spring growth. It was decided not to prune the remaining unpruned trees. During the first growing season a fortuitous finding occurred. The unpruned trees grew faster and had fewer failures than the pruned trees.
But perhaps these observations were merely due to species differences. Follow-up experiments were conducted to confirm the earlier findings that compensatory pruning was truly non-beneficial. In a total of 11 different species, subsets of trees were either pruned or not pruned to remove 15%, 30% or 45% of the canopy. Each treatment was replicated 12 times and tree responses were evaluated for two years. Again, compensatory pruning was found to be non-beneficial. Since then, three additional studies in other locations (Colorado and England) by different research teams have produced similar results.
Water Limitations
The findings in England were interesting because they suggested pruning to compensate for root loss was not the critical question; rather that soil moisture was more important. When pruned or unpruned treatments were grown in a dry soil condition they both grew very little. But when water was not a limiting factor, pruned trees had less root growth, as well as fewer, and smaller leaves. Trees not pruned at planting that received ample water had more leaf tissue to photosynthesize and a greater ability to produce tree growth.
Water Guidelines
In addition to not performing compensatory pruning, what else could be done to decrease canopy dieback, increase transplant survival, and improve tree health? The conventional tree-watering guide at that time suggested 1 – 1.5 inches (2.5 – 3.8 cm) of rain or irrigation water every seven to ten days is appropriate. Apparently this common watering guideline was always accepted as fact and never researched. Now, in recent years, the Morton Arboretum and the University of Florida have produced research that suggests more frequent watering is optimal. These results determined that newly transplanted trees benefit from:
1. daily watering for the first one to two weeks, applying approximately 1.5 gallons per caliper inch (1.5 liters per caliper centimeter) per watering,
2. after two weeks, water the trees every two to three days for the next two or three months, with approximately 1.5 gallons per caliper inch (1.5 liters per caliper cm)
3. after 2-3 months, weekly watering is necessary for the remainder of the season or until the tree is established.
4. after the first year, if watering is necessary, it should be 1 gallon of water per inch of caliper. This equates to 1 inch of rainfall per week.
Newly transplanted trees are absorbing water from a diminished rooting area, so apply all the water to the root ball area. Roots must generate and grow into surrounding soils before a larger soil volume can be tapped for moisture. When tree roots have spread into the surrounding soil, they are considered established.
Trees in northern climates will become established within one to one-and-a-half years for each caliper inch (2.5 cm) of stem. Therefore, it takes two to three years before a two-inch (5 cm) caliper tree becomes established. If you cannot adequately meet the water requirements of newly transplanted trees, planting smaller trees is recommended. For example, one inch (2.5 cm) caliper trees have less root loss and recover faster (1 year) than trees with two to three inches (5 – 7.5 cm) in stem caliper. Also keep in mind that mulching trees with a two to three-inch (5 – 7.5 cm) depth is recommended as it helps to conserve water.
Branch Removal at Planting
On the other hand, even though compensatory pruning is not recommended, some branches may require removal and most nurseries prune out co-dominant leaders, limbs that rub against each other, and poorly angled branches, long before the sale. If a problem has not been pruned in the nursery, remove it after planting. All trees should be inspected because some limbs may have been damaged in transit from the nursery to the planting site. Also, any dead, dying, and diseased branches should be removed.
Branches that are weakly attached or have included bark should be removed at planting, unless you can revisit the tree and prune it within the next few years. If removing these bad branches will result in more than 10% to 20% canopy loss, do not accept the tree. If your supplier has many trees that require extensive pruning, it may be best to either look for a new supplier of nursery stock or discuss quality issues with this supplier. Arborists often forget that as buyers we can influence the quality of nursery stock. Accepting inferior stock only perpetuates more of it entering the market.
Selecting structurally sound and healthy trees are a must. Whitcomb said it best 45 years ago: “Top pruning and other practices are unlikely to help an unthrifty tree and a thrifty tree doesn’t need it.”
Source
- Hauer, Rich, “To prune or not to prune at planting, that is the question!”, Minnesota Department of Agriculture, Agronomy and Plant Protection Division. 2011.
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.
Tree of the Seminar 57
By Len Phillips
The Katsura makes a handsome street tree. This tree has a uniform growth habit in a dense pyramidal shape and is tolerant of 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.
Trade Name: Katsura Tree
Botanical Name: Cercidiphyllum japaonicum
Parentage: Introduction from China and Japan
Family: Cercidiphyllaceae
Introduction: 1865
Hardiness Zone: 4 – 8
Height: 40' – 60' can reach 100’
Spread: 20' – 30' can spread to 60’
Growth Rate: medium to fast, 20' in 10 years
Form: Pyramidal in youth and in old age, but some become wide spreading with age
Bloom Period: Late March to early April , before leaves
Flower: Small and not showy
Fruit: Small pod up to ¾” long, seeds are thin and winged
Spring Color: Reddish purple leaves
Summer Foliage: Bluish green in summer
Autumn Foliage: Generally yellow, sometimes apricot to orange, fall leaves are fragrant
Winter Interest: Handsome and refined bark provides winter interest
Bark: Brown and slightly shaggy
Habitat: Grows throughout the eastern half of the U.S.
Culture: Prefers moist, well drained soil, irrigation needed in full sun
Pest Problems: None serious
Storm Resistance: Good
Salt Tolerance: Moderate
Planting: Difficult to transplant, use B&B or container
Propagating: Seeds and softwood cuttings
Design Uses: Specimen for lawn, park, and a street tree with ample watering
Companions: Use with evergreen groundcovers
Other Comments: Excellent tree for special locations
Available from: Most retail nurseries.
Photos: Missouri Botanical Garden
North Carolina State University
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.
By Len Phillips
The Katsura makes a handsome street tree. This tree has a uniform growth habit in a dense pyramidal shape and is tolerant of 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.
Trade Name: Katsura Tree
Botanical Name: Cercidiphyllum japaonicum
Parentage: Introduction from China and Japan
Family: Cercidiphyllaceae
Introduction: 1865
Hardiness Zone: 4 – 8
Height: 40' – 60' can reach 100’
Spread: 20' – 30' can spread to 60’
Growth Rate: medium to fast, 20' in 10 years
Form: Pyramidal in youth and in old age, but some become wide spreading with age
Bloom Period: Late March to early April , before leaves
Flower: Small and not showy
Fruit: Small pod up to ¾” long, seeds are thin and winged
Spring Color: Reddish purple leaves
Summer Foliage: Bluish green in summer
Autumn Foliage: Generally yellow, sometimes apricot to orange, fall leaves are fragrant
Winter Interest: Handsome and refined bark provides winter interest
Bark: Brown and slightly shaggy
Habitat: Grows throughout the eastern half of the U.S.
Culture: Prefers moist, well drained soil, irrigation needed in full sun
Pest Problems: None serious
Storm Resistance: Good
Salt Tolerance: Moderate
Planting: Difficult to transplant, use B&B or container
Propagating: Seeds and softwood cuttings
Design Uses: Specimen for lawn, park, and a street tree with ample watering
Companions: Use with evergreen groundcovers
Other Comments: Excellent tree for special locations
Available from: Most retail nurseries.
Photos: Missouri Botanical Garden
North Carolina State University
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.
A Case for Fencerows
By Richard H. Miller
To you and me they are just fencerows, also known as hedgerows. They are the linear habitats we walked along as kids kicking up an occasional rabbit or receiving a scolding from a very brave chickadee. To a field biologist though, they are extremely novel, disturbed habitats. Patches of a natural mosaic in a modified landscape and occupied by organisms not normally associated with the landscape before it was fragmented by man.
Function
One question we may ask is, are fencerows an integral part of the landscape and valuable habitats in their own right? The answer would be yes. In fact, biologically speaking, the argument for wildlife is that all life on earth is connected and it is extremely important to our continued well-being. Fencerows often provide the only element of structure and diversity in the landscape that has otherwise lost most of its natural habitat because of agriculture.
In addition, suburban landscapes are largely a mix of non-native plants that do not support the food chain due to the inability of native insects to convert those exotic plants to protein needed by wild animals. Organisms in fencerows surrounded by agriculture or isolated by exotic plants are generally not forest trees but have adapted to the fragmentation of native habitats as opportunistic species. This is adaption to a novel landscape created or at least altered by man.
A wide range of plants and animals such as song sparrows perceive a linear landscape as “the same throughout”. Less mobile organisms, such as a box turtle may be less likely to be viable and able to use this environment to sustain its population and to move successfully from one fragmented woodland to the next. Of course nothing is guaranteed in nature for species in fencerow habitats. If surrounded by agriculture there are farming activities such as pesticides, equipment, drought, floods, predators, and disease to deal with.
Advantages and Disadvantages
Some conservationists advocate interventions that increase habitat connectivity to sustain and enhance species that inhabit these novel landscapes. The argument is that fragmentation is destructive. Isolated pockets of habitat may not support long term viable populations. Species with specific requirements with no connectivity could be “left behind” showing a large lag in the ability to shift distributions. If successful, landscape-scale habitat connectivity could be viewed as corridors of stepping stone habitat.
The other end of the scientific spectrum believes fencerows are so diverse and complex that science currently is debating all the landscape variables over a range of scales. Therefore it is impossible to state that connectivity between fragmented woodlands is good, bad or of no effect to populations. One scientist concluded that there is no direct evidence that plants disperse progressively along hedgerows despite the large numbers of studies on the topic.
Important Fencerows
Fencerows bounded by forest on one side and agriculture on the other are extremely varied. Birds and mammals use these sites for roosting with high nest density, diverse forage opportunities and for shelter. Forest edge plants are not tolerant of forest canopy shade and exist only in this environment. These same plants are not tolerant of farming or competition from old field perennials either.
The Future of Fencerows
Property to property cultivation or even areas no longer farmed promote a coalescence of woodlands and out-compete the edge effect necessary to create and maintain a viable fencerow biology. Forty years ago on a nationwide scale we had abundant quail, rabbits and songbirds living in fencerows but they are not there today. We have to ask what has happened to fencerows and wildlife. Most are clean, devoid of any vegetation, and saturated with pesticides. Fencerows are best for wildlife when consisting of trees in a central row with native shrubs and herbaceous plants on either side.
As agriculture moves away from brushy fencerows, suburbia needs to “pick up the slack” and create “neglected” habitats in support of biological diversity. Life in the cities could use a lot less lawn and more native fencerow plants that support the planet in a very positive way.
Sources
Dick Miller is the Urban Forester for the city of Canal Winchester, Ohio
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 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.
By Richard H. Miller
To you and me they are just fencerows, also known as hedgerows. They are the linear habitats we walked along as kids kicking up an occasional rabbit or receiving a scolding from a very brave chickadee. To a field biologist though, they are extremely novel, disturbed habitats. Patches of a natural mosaic in a modified landscape and occupied by organisms not normally associated with the landscape before it was fragmented by man.
Function
One question we may ask is, are fencerows an integral part of the landscape and valuable habitats in their own right? The answer would be yes. In fact, biologically speaking, the argument for wildlife is that all life on earth is connected and it is extremely important to our continued well-being. Fencerows often provide the only element of structure and diversity in the landscape that has otherwise lost most of its natural habitat because of agriculture.
In addition, suburban landscapes are largely a mix of non-native plants that do not support the food chain due to the inability of native insects to convert those exotic plants to protein needed by wild animals. Organisms in fencerows surrounded by agriculture or isolated by exotic plants are generally not forest trees but have adapted to the fragmentation of native habitats as opportunistic species. This is adaption to a novel landscape created or at least altered by man.
A wide range of plants and animals such as song sparrows perceive a linear landscape as “the same throughout”. Less mobile organisms, such as a box turtle may be less likely to be viable and able to use this environment to sustain its population and to move successfully from one fragmented woodland to the next. Of course nothing is guaranteed in nature for species in fencerow habitats. If surrounded by agriculture there are farming activities such as pesticides, equipment, drought, floods, predators, and disease to deal with.
Advantages and Disadvantages
Some conservationists advocate interventions that increase habitat connectivity to sustain and enhance species that inhabit these novel landscapes. The argument is that fragmentation is destructive. Isolated pockets of habitat may not support long term viable populations. Species with specific requirements with no connectivity could be “left behind” showing a large lag in the ability to shift distributions. If successful, landscape-scale habitat connectivity could be viewed as corridors of stepping stone habitat.
The other end of the scientific spectrum believes fencerows are so diverse and complex that science currently is debating all the landscape variables over a range of scales. Therefore it is impossible to state that connectivity between fragmented woodlands is good, bad or of no effect to populations. One scientist concluded that there is no direct evidence that plants disperse progressively along hedgerows despite the large numbers of studies on the topic.
Important Fencerows
Fencerows bounded by forest on one side and agriculture on the other are extremely varied. Birds and mammals use these sites for roosting with high nest density, diverse forage opportunities and for shelter. Forest edge plants are not tolerant of forest canopy shade and exist only in this environment. These same plants are not tolerant of farming or competition from old field perennials either.
The Future of Fencerows
Property to property cultivation or even areas no longer farmed promote a coalescence of woodlands and out-compete the edge effect necessary to create and maintain a viable fencerow biology. Forty years ago on a nationwide scale we had abundant quail, rabbits and songbirds living in fencerows but they are not there today. We have to ask what has happened to fencerows and wildlife. Most are clean, devoid of any vegetation, and saturated with pesticides. Fencerows are best for wildlife when consisting of trees in a central row with native shrubs and herbaceous plants on either side.
As agriculture moves away from brushy fencerows, suburbia needs to “pick up the slack” and create “neglected” habitats in support of biological diversity. Life in the cities could use a lot less lawn and more native fencerow plants that support the planet in a very positive way.
Sources
- Burel, F. (1996) “Hedgerows and their role in agriculture landscapes”. Critical Reviews in Plant Sciences, 15:169-190.
- EEC (1992). Council Directive 92/43/EEC 21 May, 1992 “On the Conservation of Natural Habitats and of wild Fauna and Flora”. The official Journal of the European Communities, L206/19.
- Fisher J. & Merriam G. (2000) “Resources patch array use by two squirrel species in an agricultural landscape”. (333) Kulwer Academic Pub. Netherlands.
- Forman R. (1991) “Landscape Corridors: In Nature Conservation 2: the role of habitat corridors”, eds. D.A. Saunders and R.J. Hobbs, pp 71-84. Surrey Beatty & Sons, Chipping Norton, Australia.
Dick Miller is the Urban Forester for the city of Canal Winchester, Ohio
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 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.
Root Development
Edited by Len Phillips
How do roots begin?
When a seed germinates it produces a radical which will grow downward in response to gravity no matter which way the seed is laying. This is caused by the Earth’s gravitational pull and is known as geo-tropism. Geo-tropism is the name given to the physical process that roots take when growing in the direction of gravity. Roots show positive geo-tropism while shoots show negative geo-tropism. Not all roots grow in the direction of gravity, some grow horizontally and some grow at an angle. Photo-tropism is the process that occurs when stems grow towards light. Roots can also be affected by light but in a different way. Most roots will grow away from light in a process called negative phototropism.
Root system
Roots are very much forgotten when it comes to analyzing a tree. There is great interest in branch structure, leaf shape and color, and floral displays that a tree can produce but only a little attention is given to what can not be seen. The root system’s main function is to find water and nutrients and to anchor the plant in the ground. Roots can also store food and they are just as important as what is above ground.
Taproot
Roots anchor the plant to the ground by either a taproot or a fibrous system. Some plants have a combination of both systems. A taproot is a large root that grows in response to gravity. The taproot is lightly branched compared to the fibrous root but can grow to great depths in the soil to anchor the tree and search for water and nutrients. Only when the taproot is anchored and water and nutrients have been found, will new leaves start to produce top growth and secondary root branching. When a plant with a taproot is removed from the ground for transplanting, it is important to retain as much of the root as possible. If too many of the small roots are lost the tree might not be able to replenish the moisture loss.
Fibrous roots
A fibrous root system is a series of thin, heavily branched roots which grow within the top 3 feet (1 m) of the soil surface. A fibrous root system is a good system especially on urban trees, as it collects water and nutrients in the top layer of soil before they are leached lower down. A plant with a fibrous root system is much easier to transplant as its roots are close together so more roots and soil is retained when the tree is lifted from the ground.
Root Structure
A single root is made up of many different parts and each part is required so the root can function correctly. The youngest part of the root contains the root cap, apical meristem, and root hairs. In the older part of the root are located the lateral roots. All of the parts are required for a fully operational root system.
Root cap
The root cap protects the tip of the root when it is exploring the soil. The root cap is rubbed off as it moves through the soil but is quickly replaced by new cells which create a new root cap. When the new cells are being formed they produce a lubricant which helps the root move through the soil. The root cap also produces mucilage that aids in the uptake of water and nutrients.
Apical Meristem
The apical meristem produces new cells which increase the length of the root. The new cells are laid down behind the growing tip. The meristem is protected by the root cap because if it gets damaged it cannot regenerate itself.
Root Hairs
Root hairs are an extension of the outer root cells. The tiny hairs help to increase the surface area of the root and hence aid in the absorption of water. The root hair zone is located behind the region of elongation and the root cap, and always remains a constant width. Root hairs are ephemeral and only last for a few days. New hairs form behind the root tip while older root hairs at the top of the root hair zone shrivel and die.
Stele
The stele is the central area of the root which contains the xylem and phloem and is surrounded by a row of cells called the endodermis. The cambium separates the xylem and the phloem and generates new xylem and phloem cells. The endodermis keeps the vascular tissues separate from the cortex. Just inside the endodermis is a row of pericycle cells from which lateral roots are produced.
The xylem transports water and dissolved nutrients up from the roots to the stems and leaves where the manufacture of carbohydrates occur. The xylem usually forms a cross shaped cross-section. Phloem is located, as small cells, in the space surrounding the xylem cells. The phloem transports carbohydrates for the production of energy in the cortex. The phloem also allows for bi-directional movement of materials.
Cortex
The cortex is required to produce energy for growth of the root and for the intake of nutrients. The cortex occupies the majority of space within the root and it can use this space to store food for the winter, if required.
Lateral roots
Lateral roots occur in older root sections. The lateral roots are formed in the pericycle, which push through the endodermis, cortex and epidermis. Branching can occur if the root tip gets damaged. Branching usually occurs within four inches (10 cm) behind the damaged root area.
Root Circling
Plants are able to form their root structure naturally when field grown. Trees that are grown in the standard black plastic container for too long can develop deformed roots. Trees that are grown in containers have to contend with the size of the container as to how well their root structure will form.
As roots spread out through the growing media they reach the sides of the container wall and start to follow the contour of the container. Studies have shown that roots would follow the contour of a pot for ½ to 1 full circle of the container before it would start to grow toward the bottom of the container. When the roots reached the bottom of the container they would start circling again this time for up to 5 revolutions.
The implications of this happening are that the portion of the plant roots which have circled within the container do not straighten out when transferred into the ground. The roots remain in the circled position, with new growth only slowly expanding radially into the soil.
Further complications arise as the roots begin to thicken. In the circled position, they tighten around one another. This restricts the vascular system thus reducing the amount of water and nutrient uptake. This can cause bad root anchorage, poor root growth and even plant loss.
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 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
How do roots begin?
When a seed germinates it produces a radical which will grow downward in response to gravity no matter which way the seed is laying. This is caused by the Earth’s gravitational pull and is known as geo-tropism. Geo-tropism is the name given to the physical process that roots take when growing in the direction of gravity. Roots show positive geo-tropism while shoots show negative geo-tropism. Not all roots grow in the direction of gravity, some grow horizontally and some grow at an angle. Photo-tropism is the process that occurs when stems grow towards light. Roots can also be affected by light but in a different way. Most roots will grow away from light in a process called negative phototropism.
Root system
Roots are very much forgotten when it comes to analyzing a tree. There is great interest in branch structure, leaf shape and color, and floral displays that a tree can produce but only a little attention is given to what can not be seen. The root system’s main function is to find water and nutrients and to anchor the plant in the ground. Roots can also store food and they are just as important as what is above ground.
Taproot
Roots anchor the plant to the ground by either a taproot or a fibrous system. Some plants have a combination of both systems. A taproot is a large root that grows in response to gravity. The taproot is lightly branched compared to the fibrous root but can grow to great depths in the soil to anchor the tree and search for water and nutrients. Only when the taproot is anchored and water and nutrients have been found, will new leaves start to produce top growth and secondary root branching. When a plant with a taproot is removed from the ground for transplanting, it is important to retain as much of the root as possible. If too many of the small roots are lost the tree might not be able to replenish the moisture loss.
Fibrous roots
A fibrous root system is a series of thin, heavily branched roots which grow within the top 3 feet (1 m) of the soil surface. A fibrous root system is a good system especially on urban trees, as it collects water and nutrients in the top layer of soil before they are leached lower down. A plant with a fibrous root system is much easier to transplant as its roots are close together so more roots and soil is retained when the tree is lifted from the ground.
Root Structure
A single root is made up of many different parts and each part is required so the root can function correctly. The youngest part of the root contains the root cap, apical meristem, and root hairs. In the older part of the root are located the lateral roots. All of the parts are required for a fully operational root system.
Root cap
The root cap protects the tip of the root when it is exploring the soil. The root cap is rubbed off as it moves through the soil but is quickly replaced by new cells which create a new root cap. When the new cells are being formed they produce a lubricant which helps the root move through the soil. The root cap also produces mucilage that aids in the uptake of water and nutrients.
Apical Meristem
The apical meristem produces new cells which increase the length of the root. The new cells are laid down behind the growing tip. The meristem is protected by the root cap because if it gets damaged it cannot regenerate itself.
Root Hairs
Root hairs are an extension of the outer root cells. The tiny hairs help to increase the surface area of the root and hence aid in the absorption of water. The root hair zone is located behind the region of elongation and the root cap, and always remains a constant width. Root hairs are ephemeral and only last for a few days. New hairs form behind the root tip while older root hairs at the top of the root hair zone shrivel and die.
Stele
The stele is the central area of the root which contains the xylem and phloem and is surrounded by a row of cells called the endodermis. The cambium separates the xylem and the phloem and generates new xylem and phloem cells. The endodermis keeps the vascular tissues separate from the cortex. Just inside the endodermis is a row of pericycle cells from which lateral roots are produced.
The xylem transports water and dissolved nutrients up from the roots to the stems and leaves where the manufacture of carbohydrates occur. The xylem usually forms a cross shaped cross-section. Phloem is located, as small cells, in the space surrounding the xylem cells. The phloem transports carbohydrates for the production of energy in the cortex. The phloem also allows for bi-directional movement of materials.
Cortex
The cortex is required to produce energy for growth of the root and for the intake of nutrients. The cortex occupies the majority of space within the root and it can use this space to store food for the winter, if required.
Lateral roots
Lateral roots occur in older root sections. The lateral roots are formed in the pericycle, which push through the endodermis, cortex and epidermis. Branching can occur if the root tip gets damaged. Branching usually occurs within four inches (10 cm) behind the damaged root area.
Root Circling
Plants are able to form their root structure naturally when field grown. Trees that are grown in the standard black plastic container for too long can develop deformed roots. Trees that are grown in containers have to contend with the size of the container as to how well their root structure will form.
As roots spread out through the growing media they reach the sides of the container wall and start to follow the contour of the container. Studies have shown that roots would follow the contour of a pot for ½ to 1 full circle of the container before it would start to grow toward the bottom of the container. When the roots reached the bottom of the container they would start circling again this time for up to 5 revolutions.
The implications of this happening are that the portion of the plant roots which have circled within the container do not straighten out when transferred into the ground. The roots remain in the circled position, with new growth only slowly expanding radially into the soil.
Further complications arise as the roots begin to thicken. In the circled position, they tighten around one another. This restricts the vascular system thus reducing the amount of water and nutrient uptake. This can cause bad root anchorage, poor root growth and even plant loss.
Source
- Blackweir, Damien, “An investigation into root circling in potted nursery stock”, Waterford Institute of Technology, Waterford, Ireland, 2010.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the .5 CEUs toward Certified Arborist 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.
Cultivars of Tree-form Serviceberry
Edited by Len Phillips
The Serviceberry is commonly considered a shrub, however several cultivars have been developed that are very desirable street trees. Plus, they are among the first to bloom in the spring. 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: Amelanchier grandiflora or laevis
Common Name: Serviceberry
Family: Rosaceae
Bloom Period: Early spring
Bark: Light gray
Habitat: Native to entire US east coast, west to the Mississippi River
Culture: Somewhat sensitive to drought, soil compaction, and air pollution, likes well drained moist sites, acidic soil is best, tolerates full sun or partial shade
Growth Rate: Vigorous, full size in less than 30 years
Pest Problems: Cultivars are resistant to leaf spot and leaf insects
Storm Resistance: Good
Salt Resistance: Somewhat sensitive
Planting: Slow recovery after transplanting, very tolerant of BR and B&B planting
Pruning: Rarely needs fertilizer or pruning
Propagating: Tissue culture seems to have the best results
Companions: Use with blueberries, ferns, and other woodland plants, pines make an excellent background to show off the blooms and fall color
Other Comments: Heavily branched, these cultivars are suitable for most sites, streets and park use
Available from: Many nurseries
Allegheny Serviceberry – Amelanchier laevis – Zone: 4 – 9; Height: 25’; Spread: 15’; Shape: upright, oval, irregular; Foliage: small, green; Fall Color: orange; Flower: white, in clusters; Fruit: edible, purplish blue, 3/8” diameter. This plant is grown both as tree form and as a multi-stem shrub. It is a little taller, more upright, and more “tree-like” than most Amelanchier species. Fact Sheet
Autumn Brilliance® Serviceberry – Amelanchier x grandiflora ‘Autumn Brilliance’ – Zone: 3 – 9; Height: 20' – 25’; Spread: 15' – 25’; Shape: upright, moderately spreading; Foliage: medium to dark green, clean all summer; Fall Color: brilliant red; Flower: abundant white, in clusters; Fruit: edible, purplish blue, 1/4” diameter. This is an excellent Amelanchier with good form, strong branching, and fire blight resistance. It displays reliable spring bloom and bright fall colors. This is a selection from Bill Wandell, Urbana, IL in 1968. Fact Sheet
Cole’s Select Serviceberry – Amelanchier × grandiflora ‘Cole’s Select’ – Zone: 4 – 9; Height: 20’; Spread: 15’; Shape: upright, spreading; Foliage: small, thick, and glossy green; Fall Color: exceptional bright orange-red to red leaves; Flower: white, in clusters; Fruit: edible, purplish blue, 1/4” diameter. This Amelanchier selection has thicker, glossier foliage than the others, giving it a healthy appearance in midsummer. Fact Sheet
Princess Diana Serviceberry – Amelanchier grandiflora ‘Princess Diana’ – Zone: 3 – 9; Height: 20’; Spread: 15’ – 20’; Shape: gracefully spreading; Foliage: small, green, clean all summer; Fall Color: brilliant red long-lasting leaves; Flower: white, in clusters; Fruit: edible, purplish blue, 3/8” diameter. Princess Diana is a gracefully spreading small tree with resistance to leaf spot. Fall foliage is spectacular, coloring early, and lasting late in the season. Fact Sheet
Robin Hill Serviceberry – Amelanchier × grandiflora ‘Robin Hill’ – Zone: 4 – 9; Height: 20’ – 30’; Spread: 18’ – 25’; Shape: upright oval; Foliage: medium green with bronze tinge; Fall color: yellow to red; Flower: light pink buds fade to white flowers, in clusters; Fruit: edible, 3/8” diameter, purple. This upright growing serviceberry features pink buds that open to panicles of delicate, pale pink flowers in the spring. It develops a more uniform, shapely canopy and tree form than most other A. grandiflora cultivars. Fact Sheet
Snowcloud Serviceberry – Amelanchier laevis ‘Snowcloud’ – Zone: 4 – 9; Height: 25'; Spread: 15'; Shape: upright, oval, good tree form; Foliage: red tint in spring, dark green in summer; Fall Color: scarlet; Flower: white in clusters; Fruit: edible, 3/8" diameter, purplish blue. Selected for upright, tree form growth, this strong growing serviceberry makes a good small street tree. Fact Sheet
Spring Flurry® Serviceberry – Amelanchier laevis ‘JFS-Arb – PP #15304 – Zone: 4 – 9; Height: 28'; Spread: 20'; Shape: upright oval; Foliage: medium green; Fall Color: orange; Flower: white, in clusters; Fruit: purplish blue, edible, 3/8" diameter. This J. Frank Schmidt introduction has exceptional tree form. A dominant central leader supports strongly upward-oriented scaffold branches. Pure white blooms smother a delicate latticework of twigs in spring. These give way to healthy green foliage that turns orange in the fall. 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 Serviceberry is commonly considered a shrub, however several cultivars have been developed that are very desirable street trees. Plus, they are among the first to bloom in the spring. 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: Amelanchier grandiflora or laevis
Common Name: Serviceberry
Family: Rosaceae
Bloom Period: Early spring
Bark: Light gray
Habitat: Native to entire US east coast, west to the Mississippi River
Culture: Somewhat sensitive to drought, soil compaction, and air pollution, likes well drained moist sites, acidic soil is best, tolerates full sun or partial shade
Growth Rate: Vigorous, full size in less than 30 years
Pest Problems: Cultivars are resistant to leaf spot and leaf insects
Storm Resistance: Good
Salt Resistance: Somewhat sensitive
Planting: Slow recovery after transplanting, very tolerant of BR and B&B planting
Pruning: Rarely needs fertilizer or pruning
Propagating: Tissue culture seems to have the best results
Companions: Use with blueberries, ferns, and other woodland plants, pines make an excellent background to show off the blooms and fall color
Other Comments: Heavily branched, these cultivars are suitable for most sites, streets and park use
Available from: Many nurseries
Allegheny Serviceberry – Amelanchier laevis – Zone: 4 – 9; Height: 25’; Spread: 15’; Shape: upright, oval, irregular; Foliage: small, green; Fall Color: orange; Flower: white, in clusters; Fruit: edible, purplish blue, 3/8” diameter. This plant is grown both as tree form and as a multi-stem shrub. It is a little taller, more upright, and more “tree-like” than most Amelanchier species. Fact Sheet
Autumn Brilliance® Serviceberry – Amelanchier x grandiflora ‘Autumn Brilliance’ – Zone: 3 – 9; Height: 20' – 25’; Spread: 15' – 25’; Shape: upright, moderately spreading; Foliage: medium to dark green, clean all summer; Fall Color: brilliant red; Flower: abundant white, in clusters; Fruit: edible, purplish blue, 1/4” diameter. This is an excellent Amelanchier with good form, strong branching, and fire blight resistance. It displays reliable spring bloom and bright fall colors. This is a selection from Bill Wandell, Urbana, IL in 1968. Fact Sheet
Cole’s Select Serviceberry – Amelanchier × grandiflora ‘Cole’s Select’ – Zone: 4 – 9; Height: 20’; Spread: 15’; Shape: upright, spreading; Foliage: small, thick, and glossy green; Fall Color: exceptional bright orange-red to red leaves; Flower: white, in clusters; Fruit: edible, purplish blue, 1/4” diameter. This Amelanchier selection has thicker, glossier foliage than the others, giving it a healthy appearance in midsummer. Fact Sheet
Princess Diana Serviceberry – Amelanchier grandiflora ‘Princess Diana’ – Zone: 3 – 9; Height: 20’; Spread: 15’ – 20’; Shape: gracefully spreading; Foliage: small, green, clean all summer; Fall Color: brilliant red long-lasting leaves; Flower: white, in clusters; Fruit: edible, purplish blue, 3/8” diameter. Princess Diana is a gracefully spreading small tree with resistance to leaf spot. Fall foliage is spectacular, coloring early, and lasting late in the season. Fact Sheet
Robin Hill Serviceberry – Amelanchier × grandiflora ‘Robin Hill’ – Zone: 4 – 9; Height: 20’ – 30’; Spread: 18’ – 25’; Shape: upright oval; Foliage: medium green with bronze tinge; Fall color: yellow to red; Flower: light pink buds fade to white flowers, in clusters; Fruit: edible, 3/8” diameter, purple. This upright growing serviceberry features pink buds that open to panicles of delicate, pale pink flowers in the spring. It develops a more uniform, shapely canopy and tree form than most other A. grandiflora cultivars. Fact Sheet
Snowcloud Serviceberry – Amelanchier laevis ‘Snowcloud’ – Zone: 4 – 9; Height: 25'; Spread: 15'; Shape: upright, oval, good tree form; Foliage: red tint in spring, dark green in summer; Fall Color: scarlet; Flower: white in clusters; Fruit: edible, 3/8" diameter, purplish blue. Selected for upright, tree form growth, this strong growing serviceberry makes a good small street tree. Fact Sheet
Spring Flurry® Serviceberry – Amelanchier laevis ‘JFS-Arb – PP #15304 – Zone: 4 – 9; Height: 28'; Spread: 20'; Shape: upright oval; Foliage: medium green; Fall Color: orange; Flower: white, in clusters; Fruit: purplish blue, edible, 3/8" diameter. This J. Frank Schmidt introduction has exceptional tree form. A dominant central leader supports strongly upward-oriented scaffold branches. Pure white blooms smother a delicate latticework of twigs in spring. These give way to healthy green foliage that turns orange in the fall. 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.
The Secret to Planting Success
By Mike Amaranthus
The clearing of natural areas and new construction in the urban and suburban areas represents the extreme of soil and tree disturbance. Getting trees established is often a great challenge. Numerous tight or tenuous links between trees and soil microorganisms are broken. These linkages have allowed trees to survive and thrive in natural environments for millions of years without the use of fertilizers, pesticides, and irrigation. Arborists are now gaining increased appreciation of the living soil and more frequently incorporating soil biology and mycorrhizal products into their practices.
What are Mycorrhizae?
More than 90% of the world's tree species form a symbiotic arrangement with beneficial soil fungi called mycorrhizal fungi. The tree's roots are colonized by the soil fungus, which attaches to the roots and extends far into the surrounding soil environment. The colonized root is called a mycorrhiza. Mycorrhizal fungi are the dominant microbes in undisturbed soils accounting for 60% to 80% of the microbial biomass. Mycorrhizae are fundamental to tree establishment, supplying the water and nutrients needed for tree survival and in exchange, receiving essential sugars and other compounds supplied by the tree for mycorrhizae survival.
There are basically two broad groups of mycorrhizal fungi:
1. those forming ectomycorrhizae, so termed because they provide an external modification to the root,
2. those termed arbuscular mycorrhizae (formerly termed endomycorrhizae), are internal and are formed within the root cells.
Ectomycorrhizae
Trees forming ectomycorrhizae include the vast majority of the commercially grown tree species in the temperate and northern forests and 70% of the tree species planted in the tropics. Ectomycorrhizal fungi benefit most conifer species, such as pine, fir, spruce, and hemlock, and hardwoods such as oak, birch, beech, and madrone.
Arbuscular Mycorrhizae
Most of the commercially important horticultural and agricultural plants form arbuscular mycorrhizae (also commonly referred to as “AM”, “VAM“ and “endo mycorrhizae”). Unlike the ectomycorrhizae, no external modification of the root accompanies arbuscular mycorrhizae. Arbuscular mycorrhizal fungi benefit ash, gum, maple, and other trees, as well as shrubs and ornamental plants.
There are few trees that don’t rely on mycorrhizae in their natural environment, and most non-mycorrhizal trees are “weedy species” that can get the upper hand following disturbance events and raise havoc with existing mycorrhizal fungi.
What do they do for trees?
These mycorrhizal fungi increase the surface absorbing area of roots by ten to one thousand times, thereby greatly improving the ability of the trees to use soil resources. This means that mycorrhizal fungi increase a tree's nutrient uptake by increasing the absorbing surface area of roots. Mycorrhizal fungi release powerful chemicals into the soil that dissolve hard-to-capture nutrients, such as phosphorous, iron, and other “tightly bound” soil nutrients. This extraction process is particularly important in tree nutrition and explains why non-mycorrhizal trees require frequent fertilizer treatments to maintain their health. Mycorrhizal fungi form an intricate web that captures and assimilates nutrients in soils. In non-mycorrhizal conditions, much fertility is unavailable to trees or lost from the soil system by leaching beyond the limits of the roots.
What other functions do they perform?
Mycorrhizal fungi are involved with a wide variety of other activities that benefit tree establishment and growth. The same extensive network of fungal filaments important to nutrient uptake are also important in water uptake and storage. In soil conditions where there is no irrigation, mycorrhizal trees are under far less drought stress compared to non-mycorrhizal trees. Suppression of diseases and pathogens are additional benefits for a mycorrhizal tree. Mycorrhizal fungi attack pathogen or disease organisms entering the root zone. For example, excretions of specific antibiotics produced by mycorrhizal fungi immobilize and kill disease organisms. These mycorrhizal fungi protect trees from Phytophthora, Fusarium, and Rhizoctonia.
Mycorrhizal fungi also improve soil structure. Mycorrhizal filaments produce humic compounds and organic “glues” (extracellular polysaccharides) that bind soils into aggregates and improve soil porosity. Soil porosity and soil structure positively influence the growth of trees by promoting aeration, water movement into the soil, root growth, and root distribution.
Many practical benefits can be expected from using mycorrhizal fungi in common practices. These include improved survival, growth; more rooting, flowering, and fruiting; protection against disease; improved soil structure; and resistance to invasion by non-mycorrhizal or exotic tree species.
Mycorrhizal Relationships
The tree – mycorrhizal fungi relationship is the best understood subject in the field of soil biology. There are thousands of scientific studies on the subject. The mycorrhizal fungi relationship with trees is one of nature’s longest and most successful experiments. The earliest fossil record of the roots on land plants contain arbuscular mycorrhizae almost identical to what is found today. Most scientists today believe the tree – mycorrhizal relationship allowed aquatic plants to make the transition to the relatively harsh terrestrial environment some 430 million years ago. In nature, mycorrhizae make tree growth possible, linking the roots of trees to the surrounding soil. In nature, neither can survive without the other.
Mycorrhizae in Disturbed Habitats
Soils from natural and undisturbed areas generally contain robust and diverse populations of mycorrhizal fungi. Events that seriously disturb soil can substantially reduce or eliminate these beneficial microbes. Research shows that compaction, erosion, grading, topsoil removal, overgrazing, and the use of soil-less mixes in growing operations often eliminate mycorrhizae completely. The arbuscular mycorrhizae and many of the top-performing ectomycorrhizal fungi do not disperse their spores in the wind and instead move by growing root-to-root or move with wildlife species.
In a disturbed habitat, the effectiveness of the return of mycorrhizae is dependent on the quality and proximity of undisturbed habitats containing suitable fungi and their associated animal vectors. Many cases have been documented where trees in disturbed urban and suburban environments have not formed mycorrhizae many years after planting and are surviving only through intensive care and maintenance.
Using Fertilizer
Many fertilizer regimens push top growth at the expense of root development, making plants vulnerable to stressful environments. Frequent, high levels of fertilizer produce an unbalanced and often unsustainable shoot-to-root ratio. Mycorrhizae, on the other hand, feed plants and stimulate root growth. Unlike mycorrhizae, fertilizer alone cannot prevent root disease, improve soil structure, or promote other beneficial microbes. Fertilizers can lead to other side effects, such as deterioration of water quality, soil structure and excess soil salinity. The mycorrhizal relationship improves feeder-root production, and a mycorrhizal tree can better utilize added fertilizer.
Mycorrhizal Products
High-quality commercial mycorrhizal inoculum is now available from a variety of sources. Inoculums containing mixtures of species of mycorrhizal fungi often give the best response. Mycorrhizal inoculum comes in granular, powder, liquid, and tablet forms. The most important factor is to get the mycorrhizal propagules near the root systems of the target trees. Most mycorrhizal propagules will stay dormant until root activity begins.
The chemicals pumped into the soil by active roots cause mycorrhizal propagules to become active and grow. Inoculum can be incorporated into the planting hole at the time of transplanting, watered into porous soils, mixed into soil-less mixes, or directly dipped onto bare roots using gels. The form and application of the mycorrhizal inoculum depends upon the needs of the applicator. What is clear is that on disturbed and stressful sites, inoculation is highly effective.
Micro reality
Growing trees in a nursery and establishing trees on disturbed sites require an understanding of the many soil processes important in facilitating uptake, storage, and cycling of nutrients and water by tree species. In nature, these activities are largely performed by the microorganisms working hard below the soil surface in the living soil. In past decades, clearing of natural areas and disturbances in suburban and urban environments have substantially reduced mycorrhizal populations. Because above ground and below ground tree/soil systems are tightly interdependent, such changes can result in poor tree survival and health. Thus, a reliance on intensive and artificial tree care programs is necessary.
Hope for restoring beneficial mycorrhizal fungi and their important relationship with trees has been aided with the development of quality and increasingly inexpensive sources of mycorrhizal inoculum. Arborists working in the urban environment should now incorporate mycorrhizal fungi into their programs.
Mike Amaranthus, Ph.D.,is president and chief scientist for Mycorrhizal Applications Inc.
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 Mike Amaranthus
The clearing of natural areas and new construction in the urban and suburban areas represents the extreme of soil and tree disturbance. Getting trees established is often a great challenge. Numerous tight or tenuous links between trees and soil microorganisms are broken. These linkages have allowed trees to survive and thrive in natural environments for millions of years without the use of fertilizers, pesticides, and irrigation. Arborists are now gaining increased appreciation of the living soil and more frequently incorporating soil biology and mycorrhizal products into their practices.
What are Mycorrhizae?
More than 90% of the world's tree species form a symbiotic arrangement with beneficial soil fungi called mycorrhizal fungi. The tree's roots are colonized by the soil fungus, which attaches to the roots and extends far into the surrounding soil environment. The colonized root is called a mycorrhiza. Mycorrhizal fungi are the dominant microbes in undisturbed soils accounting for 60% to 80% of the microbial biomass. Mycorrhizae are fundamental to tree establishment, supplying the water and nutrients needed for tree survival and in exchange, receiving essential sugars and other compounds supplied by the tree for mycorrhizae survival.
There are basically two broad groups of mycorrhizal fungi:
1. those forming ectomycorrhizae, so termed because they provide an external modification to the root,
2. those termed arbuscular mycorrhizae (formerly termed endomycorrhizae), are internal and are formed within the root cells.
Ectomycorrhizae
Trees forming ectomycorrhizae include the vast majority of the commercially grown tree species in the temperate and northern forests and 70% of the tree species planted in the tropics. Ectomycorrhizal fungi benefit most conifer species, such as pine, fir, spruce, and hemlock, and hardwoods such as oak, birch, beech, and madrone.
Arbuscular Mycorrhizae
Most of the commercially important horticultural and agricultural plants form arbuscular mycorrhizae (also commonly referred to as “AM”, “VAM“ and “endo mycorrhizae”). Unlike the ectomycorrhizae, no external modification of the root accompanies arbuscular mycorrhizae. Arbuscular mycorrhizal fungi benefit ash, gum, maple, and other trees, as well as shrubs and ornamental plants.
There are few trees that don’t rely on mycorrhizae in their natural environment, and most non-mycorrhizal trees are “weedy species” that can get the upper hand following disturbance events and raise havoc with existing mycorrhizal fungi.
What do they do for trees?
These mycorrhizal fungi increase the surface absorbing area of roots by ten to one thousand times, thereby greatly improving the ability of the trees to use soil resources. This means that mycorrhizal fungi increase a tree's nutrient uptake by increasing the absorbing surface area of roots. Mycorrhizal fungi release powerful chemicals into the soil that dissolve hard-to-capture nutrients, such as phosphorous, iron, and other “tightly bound” soil nutrients. This extraction process is particularly important in tree nutrition and explains why non-mycorrhizal trees require frequent fertilizer treatments to maintain their health. Mycorrhizal fungi form an intricate web that captures and assimilates nutrients in soils. In non-mycorrhizal conditions, much fertility is unavailable to trees or lost from the soil system by leaching beyond the limits of the roots.
What other functions do they perform?
Mycorrhizal fungi are involved with a wide variety of other activities that benefit tree establishment and growth. The same extensive network of fungal filaments important to nutrient uptake are also important in water uptake and storage. In soil conditions where there is no irrigation, mycorrhizal trees are under far less drought stress compared to non-mycorrhizal trees. Suppression of diseases and pathogens are additional benefits for a mycorrhizal tree. Mycorrhizal fungi attack pathogen or disease organisms entering the root zone. For example, excretions of specific antibiotics produced by mycorrhizal fungi immobilize and kill disease organisms. These mycorrhizal fungi protect trees from Phytophthora, Fusarium, and Rhizoctonia.
Mycorrhizal fungi also improve soil structure. Mycorrhizal filaments produce humic compounds and organic “glues” (extracellular polysaccharides) that bind soils into aggregates and improve soil porosity. Soil porosity and soil structure positively influence the growth of trees by promoting aeration, water movement into the soil, root growth, and root distribution.
Many practical benefits can be expected from using mycorrhizal fungi in common practices. These include improved survival, growth; more rooting, flowering, and fruiting; protection against disease; improved soil structure; and resistance to invasion by non-mycorrhizal or exotic tree species.
Mycorrhizal Relationships
The tree – mycorrhizal fungi relationship is the best understood subject in the field of soil biology. There are thousands of scientific studies on the subject. The mycorrhizal fungi relationship with trees is one of nature’s longest and most successful experiments. The earliest fossil record of the roots on land plants contain arbuscular mycorrhizae almost identical to what is found today. Most scientists today believe the tree – mycorrhizal relationship allowed aquatic plants to make the transition to the relatively harsh terrestrial environment some 430 million years ago. In nature, mycorrhizae make tree growth possible, linking the roots of trees to the surrounding soil. In nature, neither can survive without the other.
Mycorrhizae in Disturbed Habitats
Soils from natural and undisturbed areas generally contain robust and diverse populations of mycorrhizal fungi. Events that seriously disturb soil can substantially reduce or eliminate these beneficial microbes. Research shows that compaction, erosion, grading, topsoil removal, overgrazing, and the use of soil-less mixes in growing operations often eliminate mycorrhizae completely. The arbuscular mycorrhizae and many of the top-performing ectomycorrhizal fungi do not disperse their spores in the wind and instead move by growing root-to-root or move with wildlife species.
In a disturbed habitat, the effectiveness of the return of mycorrhizae is dependent on the quality and proximity of undisturbed habitats containing suitable fungi and their associated animal vectors. Many cases have been documented where trees in disturbed urban and suburban environments have not formed mycorrhizae many years after planting and are surviving only through intensive care and maintenance.
Using Fertilizer
Many fertilizer regimens push top growth at the expense of root development, making plants vulnerable to stressful environments. Frequent, high levels of fertilizer produce an unbalanced and often unsustainable shoot-to-root ratio. Mycorrhizae, on the other hand, feed plants and stimulate root growth. Unlike mycorrhizae, fertilizer alone cannot prevent root disease, improve soil structure, or promote other beneficial microbes. Fertilizers can lead to other side effects, such as deterioration of water quality, soil structure and excess soil salinity. The mycorrhizal relationship improves feeder-root production, and a mycorrhizal tree can better utilize added fertilizer.
Mycorrhizal Products
High-quality commercial mycorrhizal inoculum is now available from a variety of sources. Inoculums containing mixtures of species of mycorrhizal fungi often give the best response. Mycorrhizal inoculum comes in granular, powder, liquid, and tablet forms. The most important factor is to get the mycorrhizal propagules near the root systems of the target trees. Most mycorrhizal propagules will stay dormant until root activity begins.
The chemicals pumped into the soil by active roots cause mycorrhizal propagules to become active and grow. Inoculum can be incorporated into the planting hole at the time of transplanting, watered into porous soils, mixed into soil-less mixes, or directly dipped onto bare roots using gels. The form and application of the mycorrhizal inoculum depends upon the needs of the applicator. What is clear is that on disturbed and stressful sites, inoculation is highly effective.
Micro reality
Growing trees in a nursery and establishing trees on disturbed sites require an understanding of the many soil processes important in facilitating uptake, storage, and cycling of nutrients and water by tree species. In nature, these activities are largely performed by the microorganisms working hard below the soil surface in the living soil. In past decades, clearing of natural areas and disturbances in suburban and urban environments have substantially reduced mycorrhizal populations. Because above ground and below ground tree/soil systems are tightly interdependent, such changes can result in poor tree survival and health. Thus, a reliance on intensive and artificial tree care programs is necessary.
Hope for restoring beneficial mycorrhizal fungi and their important relationship with trees has been aided with the development of quality and increasingly inexpensive sources of mycorrhizal inoculum. Arborists working in the urban environment should now incorporate mycorrhizal fungi into their programs.
Mike Amaranthus, Ph.D.,is president and chief scientist for Mycorrhizal Applications Inc.
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.
Trees in Threes #57
Edited by Len Phillips
We now realize that arborists need a diversity of trees in our urban forests, to guard against disasters like Dutch elm disease. We need to plant more of the superior trees developed through genetic research to utilize the practical experience from practitioners of urban forestry. We have to plan the planting of city trees, and understand the problems and potentials of our actions. However, many cities prefer or have policies to plant the same tree at every suitable location along an entire block. The intention is to improve the aesthetics of the city. But, to avoid monoculture problems in the future, it is clear that plantings like this must be avoided.
Fortunately, it is possible to gain diversity without giving up the aesthetic advantages of uniformity. Through the careful selection and grouping of trees into similar sizes and textures, communities of trees can be created. This provides a genetic diversity while maintaining a visual uniformity. As new pests and diseases inhabit our woody landscapes, species diversity will be a critical key to minimizing their potentially negative impact.
An example combining the best of both worlds might be using Dakota Pinnacle Birch, Fastigiate Beech, and Frans Fontaine Hornbeam if you are looking for a row of narrow, columnar trees with smooth, gray bark that grow 35 – 45 feet high and 15 feet wide.
Dakota Pinnacle® Birch – Betula platyphylla ‘Fargo’ PP10963
Height: 40'
Spread: 15'
Shape: Narrowly pyramidal
Bark: Silvery white color, smooth and attractive
Zone: 3
Foliage: Dark green leaves.
Fall Color: Yellow
Insect Resistance: Japanese beetle
Fact Sheet
Developed by North Dakota State University, this very cold hardy birch is well adapted to the tough climate of the northern plains. A stiffly upright, narrowly pyramidal form, combined with dense, dark green foliage and silver colored bark give it a striking appearance.
Frans Fontaine Hornbeam – Carpinus betulus ‘Frans Fontaine’
Height: 35'
Spread: 15'
Shape: Narrow, columnar
Bark: Slate gray color, smooth and attractive
Zone: 5
Foliage: Dark green.
Fall Color: Yellowish green
Fact Sheet
Fastigiate form is maintained with maturity and this tree is the narrowest of the C. betulus cultivars. This tree is used as a hedge in England because of the dense, compact, close-knit nature of the ascending branches. The current season’s growth curves inward toward the central leader producing the narrow, columnar form that continues as the tree ages.
Fastigiate Beech – Fagus sylvatica ‘Fastigiata’ (‘Dawyck’)
Height: 45’
Spread: 15’
Shape: Columnar, fastigiate
Bark: Smooth gray color, exceptionally attractive
Zone: 5
Foliage: Dark green
Fall Color: Gold
Fact Sheet
Deep green foliage and the tightness of its fastigiate form make this one of the most striking of columnar trees. This cultivar was introduced in 1913, at the Hesse Nursery of Weener, Hanover, Germany. This tree also makes an excellent hedge because it withstands heavy pruning.
Next Seminar – need three trees with a round form that is 20 feet by 20 feet and has white flowers?
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
We now realize that arborists need a diversity of trees in our urban forests, to guard against disasters like Dutch elm disease. We need to plant more of the superior trees developed through genetic research to utilize the practical experience from practitioners of urban forestry. We have to plan the planting of city trees, and understand the problems and potentials of our actions. However, many cities prefer or have policies to plant the same tree at every suitable location along an entire block. The intention is to improve the aesthetics of the city. But, to avoid monoculture problems in the future, it is clear that plantings like this must be avoided.
Fortunately, it is possible to gain diversity without giving up the aesthetic advantages of uniformity. Through the careful selection and grouping of trees into similar sizes and textures, communities of trees can be created. This provides a genetic diversity while maintaining a visual uniformity. As new pests and diseases inhabit our woody landscapes, species diversity will be a critical key to minimizing their potentially negative impact.
An example combining the best of both worlds might be using Dakota Pinnacle Birch, Fastigiate Beech, and Frans Fontaine Hornbeam if you are looking for a row of narrow, columnar trees with smooth, gray bark that grow 35 – 45 feet high and 15 feet wide.
Dakota Pinnacle® Birch – Betula platyphylla ‘Fargo’ PP10963
Height: 40'
Spread: 15'
Shape: Narrowly pyramidal
Bark: Silvery white color, smooth and attractive
Zone: 3
Foliage: Dark green leaves.
Fall Color: Yellow
Insect Resistance: Japanese beetle
Fact Sheet
Developed by North Dakota State University, this very cold hardy birch is well adapted to the tough climate of the northern plains. A stiffly upright, narrowly pyramidal form, combined with dense, dark green foliage and silver colored bark give it a striking appearance.
Frans Fontaine Hornbeam – Carpinus betulus ‘Frans Fontaine’
Height: 35'
Spread: 15'
Shape: Narrow, columnar
Bark: Slate gray color, smooth and attractive
Zone: 5
Foliage: Dark green.
Fall Color: Yellowish green
Fact Sheet
Fastigiate form is maintained with maturity and this tree is the narrowest of the C. betulus cultivars. This tree is used as a hedge in England because of the dense, compact, close-knit nature of the ascending branches. The current season’s growth curves inward toward the central leader producing the narrow, columnar form that continues as the tree ages.
Fastigiate Beech – Fagus sylvatica ‘Fastigiata’ (‘Dawyck’)
Height: 45’
Spread: 15’
Shape: Columnar, fastigiate
Bark: Smooth gray color, exceptionally attractive
Zone: 5
Foliage: Dark green
Fall Color: Gold
Fact Sheet
Deep green foliage and the tightness of its fastigiate form make this one of the most striking of columnar trees. This cultivar was introduced in 1913, at the Hesse Nursery of Weener, Hanover, Germany. This tree also makes an excellent hedge because it withstands heavy pruning.
Next Seminar – need three trees with a round form that is 20 feet by 20 feet and has white flowers?
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