Seminar #99 from Online Seminars for Municipal Arborists
July - September 2023
Sections Go directly to the section by clicking on the title below
July - September 2023
Sections Go directly to the section by clicking on the title below
Note: Click on green text in each section for more information and photos.
Genetic Engineering of Trees
Edited by Len Phillips
Tree genetic engineering is a technology that involves the manipulation of an organism's genome for the purpose of altering its characteristics. It involves introducing genetic material from one organism into another in order to eliminate bad traits or to create new traits, but mostly to modify existing ones.
Genetic material can be found in every living organism, including trees, plants, animals, bacteria, and viruses. Genetic engineering can be used to:
The technology also has potential applications in the production of renewable energy, such as bio-fuels. Genetic engineering of plants can be done through a variety of methods, such as gene slicing, gene editing, targeted mutagenesis, and transgenic technology.
Genetic engineering of trees specifically can be used to produce:
The future of genetic engineering holds tremendous potential. Scientists are constantly making new advancements in the field, allowing for more precise and efficient genetic modifications. As technology continues to progress, it is likely that new techniques will be developed that would allow for more precise and targeted genetic modifications, thus opening up new possibilities for improving the health of trees and creating new tree varieties.
Source:
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Utility, Municipal Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA science credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Edited by Len Phillips
Tree genetic engineering is a technology that involves the manipulation of an organism's genome for the purpose of altering its characteristics. It involves introducing genetic material from one organism into another in order to eliminate bad traits or to create new traits, but mostly to modify existing ones.
Genetic material can be found in every living organism, including trees, plants, animals, bacteria, and viruses. Genetic engineering can be used to:
- make plants more resistant to disease, drought, and pests;
- improve plant and animals nutritional value;
- modify their flavor, color, and other physical characteristics.
The technology also has potential applications in the production of renewable energy, such as bio-fuels. Genetic engineering of plants can be done through a variety of methods, such as gene slicing, gene editing, targeted mutagenesis, and transgenic technology.
Genetic engineering of trees specifically can be used to produce:
- trees designed with resistance to pests, reducing the need for chemical pesticides.
- trees designed to require less water, fertilizer, and energy, thus reducing the environmental impact.
The future of genetic engineering holds tremendous potential. Scientists are constantly making new advancements in the field, allowing for more precise and efficient genetic modifications. As technology continues to progress, it is likely that new techniques will be developed that would allow for more precise and targeted genetic modifications, thus opening up new possibilities for improving the health of trees and creating new tree varieties.
Source:
- John Rodriquez, "Plant Genetic Engineering", Powerupio Electronics
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Utility, Municipal Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA science credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Birds and the Plants They Love
Edited by Len Phillips
Native trees play a vital role in the lives of birds by providing them with the means to survive. Trees and plants provide food, shelter, and a resting site for birds. You can attract birds into your city by growing the trees and plants they like. For example:
It is the human being's responsibility to protect birds and the environment by planting native plants. Especially the plants that are preferred by birds and other wildlife.
Sources:
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Utility, Municipal Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA management credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Edited by Len Phillips
Native trees play a vital role in the lives of birds by providing them with the means to survive. Trees and plants provide food, shelter, and a resting site for birds. You can attract birds into your city by growing the trees and plants they like. For example:
- The Mountain Bluebirds survive the winter in the hiding spots of hackberry trees that also produce an abundant supply of berries that usually last through the winter.
- The Yellow-throated Warblers cover themselves with the pollen from Loblolly Pines, which are most common in the southeastern United States.
- Dead Loblolly Pines provide Woodpeckers with places for cavity nesting.
- Big Sagebrush grows in the arid deserts of the western US plains and play an important role in the ecosystems where the Mountain Bluebirds migrate to breed. The Sagebrush also help to sustain the lives of the greater sage-grouse and more than 350 animal species, by offering nesting materials and food.
- Curve-billed Thrashers in Arizona build their nests with small sticks tucked safely within the tiny spikes of the Cholla Cactus. The cactus also offers the birds shady relief during hot summer days.
- The black and orange Varied Thrushes enjoy eating and living among Crabapples throughout the year. The Crabapple flowers attract bees and other pollinators in the spring with their fragrant flowers that cover the tree.
- The Red-breasted Nuthatches consume the insects that grow and hide inside the hexagonal-pored polypore fungus that are often found on decaying tree branches throughout North America.
- The Rufous Hummingbirds love the nectar of the Blue Flag Iris that grows just about everywhere in North America. The iris prefers moist soil and are typically found growing in clusters in marshes and wetlands. Bees and butterflies pollinate the iris flowers, and tiger moth caterpillars feed on the long, sword-shaped iris leaves.
- The Hard-stemmed Bulrush that grows in dense wetland clusters across North America supplies cover and resting sites for many different songbirds in riparian areas. Ducks also rely on the seeds of the dried bulrush flower heads.
- The berries and seeds of Staghorn Sumacs, which are native to the eastern United States, provide an important source of food for Eastern Bluebirds and other small birds.
- Black Cherry trees that are native to the U.S. east coast provide bountiful berries for many birds, including Scarlet Tanagers, Ruffed Grouse, Wild Turkeys, Eastern Bluebirds, and Cedar Waxwings. Black Cherry trees can reach up to 80 feet in height in full sun. The rough seed that is encased in the fleshy cherry fruits need to pass through a bird's or small mammal’s gut to germinate. These trees and wildlife need each other.
- Coast Live Oaks provide canopy cover and acorns for many mammals and birds, including California Scrub Jays. The shrubby green leaves of the Coast Live Oaks resprout soon after wildfires, and they shed their old leaves only when new leaves arrive in the spring.
- The Red-winged Blackbirds enjoy the shady covering of the Rose Spirea bushes that flourish in the northwest part of the United States.
- The pinkish-red flowers of Rose Spireas that bloom in the summer provide a wealth of nectar for hummingbirds, moths, and butterflies.
- Rose-breasted Grosbeaks are attracted to the bright pink flowers of the Eastern Redbud, which is a tree that is native to eastern North America. A vast variety of butterflies, hummingbirds, and honeybees also enjoy the redbud's nectar.
- Red-breasted Nuthatches are often seen with a small pine seed in their bills and perched on the spiky branches of Pitch Pine trees that mostly occupy the eastern United States. Dark-eyed Juncos, chickadees, and red squirrels also enjoy eating the seeds from pinecones.
- The Song Sparrows flock on cattails in Washington state to gather nesting materials. The fluffy cattails are an ideal nest-lining material for many native birds that build nests in the springtime.
- Winterberry Hollies are a major food provider for local and migrating birds during autumn and winter. Eastern Bluebirds on the winterberry shrub are a breathtaking sight during the colder months and remind us of the benefits of replanting native plant species to attract birds to urban and suburban areas.
- Local trees, shrubs and flora not only provide abundant food, shelter, and resting places for birds but also create a habitat for them.
It is the human being's responsibility to protect birds and the environment by planting native plants. Especially the plants that are preferred by birds and other wildlife.
Sources:
- McKee, J. (Feb 11, 2022), Photos that highlight how native plants support birds. Audubon.
- Liao, K. (2019, Aug 15). “Native plants share the spotlight in these stunning bird photos. Audubon.
- Johnson, K. (2020, Sep 28). ”These Fantastic Photos Show Birds Thriving With Native Plants.” Audubon.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Utility, Municipal Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA management credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
City Habitat for Insects
Edited by Len Phillips
A global decline in the diversity of plants and animals has led to an increased focus on the topic of biodiversity. The increase of urbanization can result in the loss of biodiversity and cities generally have lower densities of species compared to non-city areas. This has made biodiversity in cities an important concept because cities can support people, plants, and animals, but knowledge is required by the people responsible for planning and managing city parks and green spaces.
Trees are a vital component of city parks and green spaces and have great importance for improving biodiversity in city open spaces. Knowledge of how plants and trees interact with other species is important when aiming to improve biodiversity. Some research on the subject suggests that native plants are better for improving biodiversity. However, there is research that claims that non-native plants in urban areas can provide benefits including biodiversity and other ecosystem-services. Most trees, regardless of species, share similar characteristics such as bark, branches, flowers, and leaves that could be important habitats for insects, an invertebrate group that is a prerequisite for biodiversity on higher trophic levels.
In Sweden, a long-term research project regarding biodiversity in city environments is currently under way. The data being collected for this longer project is intended for further studies about biodiversity in city trees and green spaces. The research question for this research is: Does geographical origin or tree morphological traits affect a tree’s suitability to act as a host for local insect fauna? The aim is to gain a better understanding of the complex interactions between species of trees and insects.
Such understanding could be used in different fields and disciplines for planning and maintaining a biodiversity-friendly city forest. The main method has been a field collection of insects from trees in a forest with a supporting study of trees as insect habitats. The criteria for trees inventoried was old age, geographical origin, and presence in both park and street environments.
This resulted in a study that evaluated 42 trees evenly divided among 6 species, Acer platanoides, Acer pseudoplatanus, Acer tataricum subsp. ginnala, Crataegus monogyna, Crataegus intricata and Crataegus orientalis. The result from literature review and field study indicated that insect abundance varies between native and non-native trees without any correlation regarding geographical origin or morphology. Crataegus monogyna had a significantly higher number of larvae than other Crataegus species and Acer pseudoplatanus had a higher number of aphids than other Acer species. According to literature and field observations, non-native trees have the same morphological prerequisites as native trees to act as habitat, which indicates that more factors than geographical origin or morphological components affects the insect abundance in a tree.
These findings may give an insight into the understanding of trees as city inhabitants. The information might prove useful to green-space planners, managers, urban ecologists, and city foresters working to improve biodiversity in cities.
Source
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Utility, Municipal Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA science credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Edited by Len Phillips
A global decline in the diversity of plants and animals has led to an increased focus on the topic of biodiversity. The increase of urbanization can result in the loss of biodiversity and cities generally have lower densities of species compared to non-city areas. This has made biodiversity in cities an important concept because cities can support people, plants, and animals, but knowledge is required by the people responsible for planning and managing city parks and green spaces.
Trees are a vital component of city parks and green spaces and have great importance for improving biodiversity in city open spaces. Knowledge of how plants and trees interact with other species is important when aiming to improve biodiversity. Some research on the subject suggests that native plants are better for improving biodiversity. However, there is research that claims that non-native plants in urban areas can provide benefits including biodiversity and other ecosystem-services. Most trees, regardless of species, share similar characteristics such as bark, branches, flowers, and leaves that could be important habitats for insects, an invertebrate group that is a prerequisite for biodiversity on higher trophic levels.
In Sweden, a long-term research project regarding biodiversity in city environments is currently under way. The data being collected for this longer project is intended for further studies about biodiversity in city trees and green spaces. The research question for this research is: Does geographical origin or tree morphological traits affect a tree’s suitability to act as a host for local insect fauna? The aim is to gain a better understanding of the complex interactions between species of trees and insects.
Such understanding could be used in different fields and disciplines for planning and maintaining a biodiversity-friendly city forest. The main method has been a field collection of insects from trees in a forest with a supporting study of trees as insect habitats. The criteria for trees inventoried was old age, geographical origin, and presence in both park and street environments.
This resulted in a study that evaluated 42 trees evenly divided among 6 species, Acer platanoides, Acer pseudoplatanus, Acer tataricum subsp. ginnala, Crataegus monogyna, Crataegus intricata and Crataegus orientalis. The result from literature review and field study indicated that insect abundance varies between native and non-native trees without any correlation regarding geographical origin or morphology. Crataegus monogyna had a significantly higher number of larvae than other Crataegus species and Acer pseudoplatanus had a higher number of aphids than other Acer species. According to literature and field observations, non-native trees have the same morphological prerequisites as native trees to act as habitat, which indicates that more factors than geographical origin or morphological components affects the insect abundance in a tree.
These findings may give an insight into the understanding of trees as city inhabitants. The information might prove useful to green-space planners, managers, urban ecologists, and city foresters working to improve biodiversity in cities.
Source
- Epsilon Archive for Student Projects, Kalle Ågren, ”Tree origin or traits?” 2022.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Utility, Municipal Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA science credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Columbus Ohio Tree Canopy
Edited by Len Phillips
The Columbus, Ohio City Council recently voted to support a plan to update the city's urban forest and begin implementing its urban forestry master plan. The plan recognizes the value of the City's urban forest. The City's trees help provide shade that cool homes while removing carbon dioxide from the air and help to improve air quality while the tree roots intercept storm water.
Implementation of this plan would greatly increase the number of trees in city neighborhoods and boost the tree canopy cover from 22% to 40% of the city by 2050.
In August 2018, the city had planted 35,718 trees from a planting program begun in 2015. By January 2019, the total had increased to 38,631. From 2015-2019, the city planted an average of 3,000 trees a year. The City plans to plant thousands of trees on a vacant school property, located adjacent to the city's Stockbridge Park.
In addition to the tree plantings, other goals in the City's urban forestry master plan include reducing net canopy losses while investing in an equitable canopy cover across all neighborhoods. Currently, the tree canopy by neighborhood ranges from 9% to as high as 41%, so some neighborhoods benefit more than others from a denser tree canopy.
Since 70% of the city's tree canopy is on private property, the City will also be working to unify its urban forestry goals by defining ordinances and policies for tree protection and preservation on private property. (The city removed 1,800 trees in 2019 that posed a property or safety hazard.)
More trees will help keep waterways cooler and protect fish and other species as well as the whole food chain in streams. The city plans to spend more to get rid of invasive plants such as honeysuckle that crowd out native trees.
In the City Council this year is a vote on a $300,000 increase of a contract with Davey Resource Group to continue a citywide street tree inventory, bringing the contract's total amount to $539,250.
Money also will be spent on tree installation, hazardous tree removal, stump grinding, tree-site preparation, and urban forestry professional services.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Municipal Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA management credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Edited by Len Phillips
The Columbus, Ohio City Council recently voted to support a plan to update the city's urban forest and begin implementing its urban forestry master plan. The plan recognizes the value of the City's urban forest. The City's trees help provide shade that cool homes while removing carbon dioxide from the air and help to improve air quality while the tree roots intercept storm water.
Implementation of this plan would greatly increase the number of trees in city neighborhoods and boost the tree canopy cover from 22% to 40% of the city by 2050.
In August 2018, the city had planted 35,718 trees from a planting program begun in 2015. By January 2019, the total had increased to 38,631. From 2015-2019, the city planted an average of 3,000 trees a year. The City plans to plant thousands of trees on a vacant school property, located adjacent to the city's Stockbridge Park.
In addition to the tree plantings, other goals in the City's urban forestry master plan include reducing net canopy losses while investing in an equitable canopy cover across all neighborhoods. Currently, the tree canopy by neighborhood ranges from 9% to as high as 41%, so some neighborhoods benefit more than others from a denser tree canopy.
Since 70% of the city's tree canopy is on private property, the City will also be working to unify its urban forestry goals by defining ordinances and policies for tree protection and preservation on private property. (The city removed 1,800 trees in 2019 that posed a property or safety hazard.)
More trees will help keep waterways cooler and protect fish and other species as well as the whole food chain in streams. The city plans to spend more to get rid of invasive plants such as honeysuckle that crowd out native trees.
In the City Council this year is a vote on a $300,000 increase of a contract with Davey Resource Group to continue a citywide street tree inventory, bringing the contract's total amount to $539,250.
Money also will be spent on tree installation, hazardous tree removal, stump grinding, tree-site preparation, and urban forestry professional services.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Municipal Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA management credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Tree of the Seminar
Taxodium mucronatum
By Len Phillips
Taxodium mucronatum, commonly known as Montezuma bald cypress, Montezuma cypress, Tule Tree or ahuehuete. This tree is a species of Taxodium that is primarily native to Mexico and Guatemala, with a few populations in the southwestern United States. It is an average of 100 feet (35 meters) in height and 38 – 40 feet (13 meters) wide. Some trees will live to be about 1,500 years old.
Tales
Mexico’s most famous tree, the enormous Tule Tree (Arbol del Tule) grows near Oaxaca City. Residents celebrate the famous Tule Tree on the second Monday of October. It’s a big party fit for a big tree!
Located inside a gated churchyard in the picturesque town of Santa Maria del Tule, there is a Montezuma cypress called the “Tule Tree” which has the widest tree and trunk dimension in the world. In 2005, its trunk had a circumference of 137.8 ft (42.0 m), equating to a diameter of 46.1ft (14.05 m). The height was 116 ft (35.4 m). The trunk was heavily buttressed, giving a higher diameter reading than the true cross-sectional of the trunk represents. When this is considered, the diameter of the 'smoothed out' trunk is 30.8 ft (9 m). This is slightly wider than the next most stout tree known, a giant sequoia with a 29.2 ft (8.90 m) diameter.
The Montezuma Cypress is roughly as old as nearby Mitla, the Zapotec religious site whose ruins draw visitors. The exact age of the tree is unknown, its existence chronicled by both the Aztecs and the Spanish that founded the city of Oaxaca with estimates ranging between 1,200 and 3,000 years old.
Local Zapotec legend holds that it was planted about 1,400 years ago by Pechocha, a priest of the god that the Aztecs would call Ehecatl, the Aztec wind god. This age is in broad agreement with the scientific estimate; its location on a sacred site to the Aztec and later taken over by the Roman Catholic Church, would also support this.
The tree is occasionally nicknamed the "Tree of Life" from the images of animals that are reputedly visible in the tree's gnarled trunk. As part of an official project local school children give tourists a tour of the tree and point out shapes of creatures on the trunk.
In 1990, it was reported that the tree is slowly dying because its roots have been damaged by water shortages, pollution, and car traffic, with 8,000 cars traveling daily on a nearby highway.
The tree is one of the oldest and largest in the world and has the widest girth. It has an age of at least 2,000 years, with
Once thought to be so large that it could only have resulted from a merger between multiple trees, modern DNA analysis has confirmed that the Tule is, in fact, a single individual.
Though it is the Tule’s spectacular girth that earns it a place in the record books, it is its gnarled bark that truly inspires the imagination. In its knots and crooks, visitors have found likenesses of human faces, lions, jaguars, elephants, and numerous other creatures.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Utility, Municipal Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA science credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Taxodium mucronatum
By Len Phillips
Taxodium mucronatum, commonly known as Montezuma bald cypress, Montezuma cypress, Tule Tree or ahuehuete. This tree is a species of Taxodium that is primarily native to Mexico and Guatemala, with a few populations in the southwestern United States. It is an average of 100 feet (35 meters) in height and 38 – 40 feet (13 meters) wide. Some trees will live to be about 1,500 years old.
Tales
Mexico’s most famous tree, the enormous Tule Tree (Arbol del Tule) grows near Oaxaca City. Residents celebrate the famous Tule Tree on the second Monday of October. It’s a big party fit for a big tree!
Located inside a gated churchyard in the picturesque town of Santa Maria del Tule, there is a Montezuma cypress called the “Tule Tree” which has the widest tree and trunk dimension in the world. In 2005, its trunk had a circumference of 137.8 ft (42.0 m), equating to a diameter of 46.1ft (14.05 m). The height was 116 ft (35.4 m). The trunk was heavily buttressed, giving a higher diameter reading than the true cross-sectional of the trunk represents. When this is considered, the diameter of the 'smoothed out' trunk is 30.8 ft (9 m). This is slightly wider than the next most stout tree known, a giant sequoia with a 29.2 ft (8.90 m) diameter.
The Montezuma Cypress is roughly as old as nearby Mitla, the Zapotec religious site whose ruins draw visitors. The exact age of the tree is unknown, its existence chronicled by both the Aztecs and the Spanish that founded the city of Oaxaca with estimates ranging between 1,200 and 3,000 years old.
Local Zapotec legend holds that it was planted about 1,400 years ago by Pechocha, a priest of the god that the Aztecs would call Ehecatl, the Aztec wind god. This age is in broad agreement with the scientific estimate; its location on a sacred site to the Aztec and later taken over by the Roman Catholic Church, would also support this.
The tree is occasionally nicknamed the "Tree of Life" from the images of animals that are reputedly visible in the tree's gnarled trunk. As part of an official project local school children give tourists a tour of the tree and point out shapes of creatures on the trunk.
In 1990, it was reported that the tree is slowly dying because its roots have been damaged by water shortages, pollution, and car traffic, with 8,000 cars traveling daily on a nearby highway.
The tree is one of the oldest and largest in the world and has the widest girth. It has an age of at least 2,000 years, with
Once thought to be so large that it could only have resulted from a merger between multiple trees, modern DNA analysis has confirmed that the Tule is, in fact, a single individual.
Though it is the Tule’s spectacular girth that earns it a place in the record books, it is its gnarled bark that truly inspires the imagination. In its knots and crooks, visitors have found likenesses of human faces, lions, jaguars, elephants, and numerous other creatures.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Utility, Municipal Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA science credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Tree Varieties
Edited by Len Phillips
If you plant a wide variety of tree species in your urban area, you might avoid your forest being wiped out by a single pest or disease. When cities are dominated by only a few species, new infestations of pests and diseases from overseas can move through the city with speed and dramatic results.
A diverse canopy is important everywhere, but particularly in cities. Urban dwellers need trees for shade, oxygen, cool urban heat islands and temperatures, and more. In addition to the benefits humans derive from trees, canopy diversity can make urban areas better habitats for wildlife like squirrels, birds, bees, and butterflies, according to a study that examined tree and flower diversity.
Some researchers recently conducted focus groups with nursery producers, landscape architects and municipal arborists. The tree growers cited market demand, sales and other business-related production issues as the main reasons to offer more diverse selections of trees for municipalities. Arborists, landscape architects and city tree professionals also mentioned ordinances and setback rules as a means to provide diversity.
Many older urban streets and residential areas were lined with a single type of tree which can look beautiful, but the practice runs counter to ensuring a long living and healthy canopy. Some people love the look of uniform street plantings, and professionals design these plantings to meet that need. However, a pest or disease can wipe out all the same species of tree in a single year.
Unfortunately, there are regulations in some municipalities and homeowner associations which, for the sake of visual harmony, limit homeowners’ selections and local governments to a list of as few as three species. A better option is to select different species that have the same physical appearance. For example, three large pyramidal shaped trees might be the Skymaster Oak, Greenspire Linden, and Redpointe Red Maple, all of which will grow 50 ft tall and 30 ft wide and have a similar look to the layman. Other groups of three can be found with a quick study of trees from the local nursery.
Many professional arborists and landscape architects suggest educating municipal policymakers about tree species diversity, how it relates to climate change and the threat of devastating diseases and pests.
As most arborists know, some types of trees will do better than others in a specific climate. It is unknown which trees will thrive in the future, so planting a variety increases the chances that at least some of them will still be around in the next 30 years. City professionals should re-examine their approved lists of species. The arborist should consider the use of less-common trees and avoid the temptation to plant an “instant landscape” with big nursery trees, because this tends to favor already common species.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Utility, Municipal Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA practice credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Edited by Len Phillips
If you plant a wide variety of tree species in your urban area, you might avoid your forest being wiped out by a single pest or disease. When cities are dominated by only a few species, new infestations of pests and diseases from overseas can move through the city with speed and dramatic results.
A diverse canopy is important everywhere, but particularly in cities. Urban dwellers need trees for shade, oxygen, cool urban heat islands and temperatures, and more. In addition to the benefits humans derive from trees, canopy diversity can make urban areas better habitats for wildlife like squirrels, birds, bees, and butterflies, according to a study that examined tree and flower diversity.
Some researchers recently conducted focus groups with nursery producers, landscape architects and municipal arborists. The tree growers cited market demand, sales and other business-related production issues as the main reasons to offer more diverse selections of trees for municipalities. Arborists, landscape architects and city tree professionals also mentioned ordinances and setback rules as a means to provide diversity.
Many older urban streets and residential areas were lined with a single type of tree which can look beautiful, but the practice runs counter to ensuring a long living and healthy canopy. Some people love the look of uniform street plantings, and professionals design these plantings to meet that need. However, a pest or disease can wipe out all the same species of tree in a single year.
Unfortunately, there are regulations in some municipalities and homeowner associations which, for the sake of visual harmony, limit homeowners’ selections and local governments to a list of as few as three species. A better option is to select different species that have the same physical appearance. For example, three large pyramidal shaped trees might be the Skymaster Oak, Greenspire Linden, and Redpointe Red Maple, all of which will grow 50 ft tall and 30 ft wide and have a similar look to the layman. Other groups of three can be found with a quick study of trees from the local nursery.
Many professional arborists and landscape architects suggest educating municipal policymakers about tree species diversity, how it relates to climate change and the threat of devastating diseases and pests.
As most arborists know, some types of trees will do better than others in a specific climate. It is unknown which trees will thrive in the future, so planting a variety increases the chances that at least some of them will still be around in the next 30 years. City professionals should re-examine their approved lists of species. The arborist should consider the use of less-common trees and avoid the temptation to plant an “instant landscape” with big nursery trees, because this tends to favor already common species.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Utility, Municipal Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA practice credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Columnar Trees for Narrow City Streets
Compiled by Len Phillips
The following trees have a columnar shape and are 25 feet or less wide. After each name, the dimensions are provided. Refer to this list if taking the test for credit. Other features and a photo of the trees are available on J. Frank Schmidt and Son Nursery website (see link in Sources).
Acer x freemani ‘Celebration’ - 'Celebration' Hybrid Maple 50' tall - 20' wide
Acer rubrum "Armstrong" - Fastigiate Red Maple 50-60' tall - 15-25' wide
Acer saccharum "Goldspire"- Goldspire Maple 40' tall - 10-15' wide
Carpinus betulus "Columnaris" - Columnar European Hornbeam 25' tall - 10' wide
Carpinus betulus "Fastigiata" - Upright European Hornbeam 30' tall - 20' wide
Fagus sylvatica ‘Fastigiata’- Pyramidal Beech 60' tall - 15' wide
Ginkgo biloba "Magyar" - Magyar Upright Ginkgo 50' tall - 25' wide
Ginkgo biloba "Princeton Sentry" - Princeton Sentry Ginkgo 65' tall - 15-20' wide
Koelreuteria paniculata ‘Fastigiata’ - ‘Fastigiata’ Goldenraintree 30' tall - 4-6' wide
Liriodendron tulipifera ‘Fastigiatum’ - Columnar Tulip Tree 60' tall - 20' wide
Prunus sargentii "Spire" - Columnar Sargent Cherry 25' tall - 15' wide
Quercus palustris "Pringreen" - Green Pillar Pin Oak 45' tall - 15' wide
Quercus robur "Fastigiata" - Columnar English Oak 50-60' tall - 10-18' wide
Quercus robur x Q. alba 'Crimsmidt' - Crimson Spire Oak 45' tall - 15' wide
Quercus x warei 'Long' Regal Prince - Regal Prince Oak 40-60' tall - 20-25' wide
Sources
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Utility, Municipal Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA science credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Compiled by Len Phillips
The following trees have a columnar shape and are 25 feet or less wide. After each name, the dimensions are provided. Refer to this list if taking the test for credit. Other features and a photo of the trees are available on J. Frank Schmidt and Son Nursery website (see link in Sources).
Acer x freemani ‘Celebration’ - 'Celebration' Hybrid Maple 50' tall - 20' wide
Acer rubrum "Armstrong" - Fastigiate Red Maple 50-60' tall - 15-25' wide
Acer saccharum "Goldspire"- Goldspire Maple 40' tall - 10-15' wide
Carpinus betulus "Columnaris" - Columnar European Hornbeam 25' tall - 10' wide
Carpinus betulus "Fastigiata" - Upright European Hornbeam 30' tall - 20' wide
Fagus sylvatica ‘Fastigiata’- Pyramidal Beech 60' tall - 15' wide
Ginkgo biloba "Magyar" - Magyar Upright Ginkgo 50' tall - 25' wide
Ginkgo biloba "Princeton Sentry" - Princeton Sentry Ginkgo 65' tall - 15-20' wide
Koelreuteria paniculata ‘Fastigiata’ - ‘Fastigiata’ Goldenraintree 30' tall - 4-6' wide
Liriodendron tulipifera ‘Fastigiatum’ - Columnar Tulip Tree 60' tall - 20' wide
Prunus sargentii "Spire" - Columnar Sargent Cherry 25' tall - 15' wide
Quercus palustris "Pringreen" - Green Pillar Pin Oak 45' tall - 15' wide
Quercus robur "Fastigiata" - Columnar English Oak 50-60' tall - 10-18' wide
Quercus robur x Q. alba 'Crimsmidt' - Crimson Spire Oak 45' tall - 15' wide
Quercus x warei 'Long' Regal Prince - Regal Prince Oak 40-60' tall - 20-25' wide
Sources
- “Narrow Streets” tree list (page 5) on the Philadelphia Approved Street Tree List
- J. Frank Schmidt & Son Co. Wholesale Nursery website
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Utility, Municipal Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA science credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Hug That Tree
Edited by Len Phillips
Controversial German forester Peter Wohlleben says trees talk to each other. He says he has a rare understanding of the inner life of trees and is able to describe it in accessible, evocative language. Now, at the age of 59, he has become an unlikely publishing sensation. His book “The Hidden Life of Trees; What they Feel” has sold more than 800,000 copies in Germany, and has hit the best-seller lists in 11 other countries, including the US and Canada.
A revolution has been taking place in the scientific understanding of trees, and Wohlleben is the first writer to convey its amazement to a general audience. The latest scientific studies, conducted at well-respected universities around the world, confirm what he has long suspected from close observation in his forest: Trees are far more alert, social, sophisticated, and intelligent than we thought.
Forest trees have evolved to live in cooperative, interdependent relationships, maintained by communication and a collective intelligence, similar to a honeybee colony or a family of people. But the real action is taking place underground, just below the surface. All the trees in every forest that is not too damaged, are connected to each other through underground fungal networks. Trees share water and nutrients through the root networks. They also use roots to communicate. They send distress signals about drought, disease, and insect attacks, so other trees alter their behavior when they receive these messages. Alarm and distress appear to be among the main topics of tree conversation.
To communicate through the network, trees send high-pitched chemical, hormonal and slow-pulsing electrical signals, which scientists are just beginning to decipher. A researcher in Switzerland has been studying the electrical pulses in plants and animals and he has identified a voltage-based signaling system in plants that appears strikingly similar to animal nervous systems.
Plants do not suffer in silence, when trees are stressed or injured, they emit sounds that could have implications for monitoring and detecting problems. Plants that need water or have recently had their stems cut produce up to roughly 35 sounds an hour. But well-hydrated and uncut plants are much quieter, making only about one sound an hour. Plants make noises that are ultrasonic and range between 20 and 100 kilohertz. That means they are so high-pitched that very few humans can hear them.
Plants do not have vocal cords or lungs. Instead, plants make noises in their xylem, the tubes that transport water and nutrients from their roots to their stems and leaves. Water in the xylem is held together by surface tension, just like water sucked through a drinking straw. When an air bubble forms or breaks in the xylem, it might make a little popping noise, and bubble formation is more likely during drought stress.
But the exact mechanism requires further study. Research teams have produced a machine-learning model to deduce whether a plant had been cut or was water stressed from the sounds it made, with about 70% accuracy. This result suggests a possible role for the audio monitoring of plants in forestry, farming, and horticulture.
Source
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Utility, Municipal Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA science credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Edited by Len Phillips
Controversial German forester Peter Wohlleben says trees talk to each other. He says he has a rare understanding of the inner life of trees and is able to describe it in accessible, evocative language. Now, at the age of 59, he has become an unlikely publishing sensation. His book “The Hidden Life of Trees; What they Feel” has sold more than 800,000 copies in Germany, and has hit the best-seller lists in 11 other countries, including the US and Canada.
A revolution has been taking place in the scientific understanding of trees, and Wohlleben is the first writer to convey its amazement to a general audience. The latest scientific studies, conducted at well-respected universities around the world, confirm what he has long suspected from close observation in his forest: Trees are far more alert, social, sophisticated, and intelligent than we thought.
Forest trees have evolved to live in cooperative, interdependent relationships, maintained by communication and a collective intelligence, similar to a honeybee colony or a family of people. But the real action is taking place underground, just below the surface. All the trees in every forest that is not too damaged, are connected to each other through underground fungal networks. Trees share water and nutrients through the root networks. They also use roots to communicate. They send distress signals about drought, disease, and insect attacks, so other trees alter their behavior when they receive these messages. Alarm and distress appear to be among the main topics of tree conversation.
To communicate through the network, trees send high-pitched chemical, hormonal and slow-pulsing electrical signals, which scientists are just beginning to decipher. A researcher in Switzerland has been studying the electrical pulses in plants and animals and he has identified a voltage-based signaling system in plants that appears strikingly similar to animal nervous systems.
Plants do not suffer in silence, when trees are stressed or injured, they emit sounds that could have implications for monitoring and detecting problems. Plants that need water or have recently had their stems cut produce up to roughly 35 sounds an hour. But well-hydrated and uncut plants are much quieter, making only about one sound an hour. Plants make noises that are ultrasonic and range between 20 and 100 kilohertz. That means they are so high-pitched that very few humans can hear them.
Plants do not have vocal cords or lungs. Instead, plants make noises in their xylem, the tubes that transport water and nutrients from their roots to their stems and leaves. Water in the xylem is held together by surface tension, just like water sucked through a drinking straw. When an air bubble forms or breaks in the xylem, it might make a little popping noise, and bubble formation is more likely during drought stress.
But the exact mechanism requires further study. Research teams have produced a machine-learning model to deduce whether a plant had been cut or was water stressed from the sounds it made, with about 70% accuracy. This result suggests a possible role for the audio monitoring of plants in forestry, farming, and horticulture.
Source
- “Wood Central”, April 4, 2023
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Utility, Municipal Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA science credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Purchasing Trees - Bidding vs Quotes
By Len Phillips
According to a survey conducted by LinkedIn's Urban Forestry Discussion Group, the urban forestry programs in cities around the country, average a C- in their city tree management programs. One exception to this survey was Wellesley, Massachusetts, where the Park and Tree Division within the Public Works Department is responsible for installing new city trees. Most of the new trees are planted on private property with public funds, as allowed by local and State laws. These laws allow communities to install public trees between the sidewalk and 20 feet from the edge of the public way and Wellesley had adopted this law as a policy. This setback practice has resulted in healthier trees that grow better, faster, and live longer than trees planted next to the street curb. Setback trees receive less damage from exhaust fumes, road salt, and car doors. Plus, their lower branches do not get hit by tall trucks; their upper branches do not grow into the utility wires; and their roots have plenty of good soil to grow in.
Throughout most of the time from 1974 into the 1990's, Wellesley set aside up to $25,000 each year for the installation of new trees. The funds were sufficient for installing an average of 300 trees every year. The trees were required to be an average of 2 inches (5 cm) in trunk diameter. Bare root was required because they were half the cost of the same tree balled and burlapped (B&B), so twice the number of trees could be installed for the funds available.
Tree Selection Process
The ordering of trees for spring planting begins in the autumn prior to the spring installation. The municipal arborist prepares a list of trees to be considered for the next season. The list contains a 50 - 50 mix of flowering trees and shade trees with one evergreen species. Half the trees mature at a large size for street tree installations and the other half are under 25 feet (7m) in height, for installing in combination with large trees or on the side of the street where overhead wires could be a potential problem.
The program placed a great emphasis on selecting and installing the trees bare root. The cost of contracted labor to do the actual installation was also very low because the holes could be dug smaller and the time to install the bare root tree was more than half of the time needed to install a tree B&B. No heavy equipment was needed to place the tree in the hole and the tree roots were stapled to the bottom of the hole, so no time-consuming staking was required. However, some years the contractor brought along a backhoe tractor to dig nice saucer shaped holes.
All the trees that were selected for installation each year were species known to do well in the urban New England environment. The trees selected did not require much maintenance, they were pest and disease resistant, the soils were matched to tree preference, which allowed the roots to grow with a minimum of effort, and the trees were cold and heat tolerant to ensure long-term survival. Every year up to ten new introductions or trees the City wanted to test in our location were added to the list so we could use the best-performing trees in the future.
Obtaining Quotes
Once a plant list was prepared, it was sent to 6 – 8 nurseries known to offer high quality trees, to obtain availability and pricing information for delivery the following spring. Most of the trees were to be quoted at 2" diameter or less and bare root, if possible. A minimum quantity of 10 trees per species was requested to take advantage of quantity discounts. Substitution of size and species or cultivar was allowed at this time only. The nurseries responded with what they expected to have available the following spring.
Using this information, the list was revised according to size, price, species, and quantity of available trees. The revised list was sent back to the nurseries for a final quote. Generally, 3 – 4 nurseries were selected for specific trees. Upon return of the quotes, purchase orders were placed with each nursery. Since so many nurseries were involved, none of the orders exceed the $10,000 threshold above which the state required competitive bidding. Therefore, the timely and expensive bidding process was avoided, and a quote system was permitted.
The same process was undertaken for selecting tree-planting contractors. At least 6 – 7 contractors known to be skilled and knowledgeable in installation techniques for bare root trees were sent quote sheets for installing a given number of trees at each of the sizes indicated on the list of trees selected. The contractors were asked to provide a unit price for installing each size tree. Again, because of the number of contractors and low costs per tree size, none of the contractors exceed the bid limit. In situations where the contractors quote the same price on the same size tree, both were awarded the contract and they split the number of plantings in that size.
With this process completed in the autumn, the budget was set and the orders were placed long before the spring rush, avoiding problems and disappointment with orders that were incomplete or not as desired.
Bidding versus Quotes
On average, the $25,000 budget purchased 300 trees. The average quoted cost of $53 for each tree plus the average quoted cost of $30 to install, totals $83 per bare root tree. (The one year that bidding was required by the city comptroller, only 75 trees could be purchased for the $25,000. The vendors doing the bidding required a fee for program management; they specified expensive B&B trees, 2" diameter minimum size, and union labor contractors to do the installation. Less than ten trees of each species or cultivar were ordered. The average cost per tree in the ground was $333.)
The Wellesley finance director decided that obtaining quotes to purchase different tree species or cultivars as separate items and the installation of different size trees as separate items, rather than bidding the entire package did not violate the bidding laws. He was convinced of this once he saw how the available dollars installed so many more trees by competitive quotes, than the competitive bidding process would allow, it was not in violation of State law.
(This idea was borrowed from the vehicle maintenance garage. They also had to put the purchase of nuts and bolts out to bid until the director indicated that there was no way the number of nuts and bolts needed each year could be predicted. With that example, the competitive quotes for each size nut and bolt did not violate the State bidding laws.)
Planting Plans
Since these trees were installed on private property, the Park and Tree Division's landscape architect consulted with the homeowner to be sure the trees were installed in the right place to enhance the landscape design of the street and the residence. They also believed the homeowner should have a choice of what tree was installed in their yard, so they would develop pride in the tree and feel a part of the entire tree installation program. For the funds available, as many as 30 different tree species were ordered. This gives the resident a wide variety of trees from which to select the tree they wanted in their yard. The program was developed with resident participation as a central goal, along with assurance that the investment in trees would not be wasted. Any left-over trees were planted on public properties such as the parks, schools, conservation areas, streets with no abutting homes, and public buildings.
The Process
The program starts with a list of residents who have heard about the program and would like trees installed on their property. The residents on this waiting list get the first choice of trees each year. The second level of priority occurs along selected streets. Each year the Tree Advisory Committee sets a priority for streets that should get new trees. These streets are then given to the Park and Tree Division who conducts an inventory of the existing trees and selected locations where trees could possibly be installed. The Division prepares planting plans to indicate the potential installation sites.
Once the waiting list was finalized and the planting location plans were accepted by the Tree Advisory Committee, the arborist contacts each homeowner to see if they were interested in having a tree installed in their front yard. If they are, the arborist makes an appointment to visit with them a couple of months prior to the installation and works with the homeowners regarding tree selection and the front yard location for each new tree. The arborist brings a book of photographs and descriptions of each of the trees that will be available. This information helps the owner select trees for their yard that they may not be familiar with. The approximate locations are marked on the lawn with stakes or spray paint. The locations and species were also noted on the street tree plan in case the stake disappears or the spray paint fades.
Installation
When this process was completed, the utility locations were marked, and the trees were delivered to the central maintenance yard where they were stored in wood chip mulch and kept watered in a manner similar to the Missouri Gravel Bed program. When weather conditions were right, the installation contractors were notified to begin. Each day they take only those bare root trees needed for the day and they would plant their trees according to the planting plans. Close supervision was essential to be sure the trees were located and installed correctly. The arborist tells the contractors that “if the tree's bare roots are exposed to sun and wind for 30 seconds, the root hairs will die”. This ensures prompt attention by the contractor when making delivery of the trees to the site as well as during the installation process. The tree roots were kept covered with wood chips or wet canvas on the delivery trucks, covered while the holes were being dug, and watered during and immediately after installation. Once the installation was completed, the trees were stapled to the ground with wood staples made by the Wellesley DPW carpentry shop, mulched, and a few days later the final inspection was made by the arborist. At this inspection, the homeowner was given a letter with the name of the tree and a description of the care the tree should receive. Only once did I find a tree (dogwood) dug up the evening after its installation near the street and moved by the homeowner to a location near the home's dining room window where the bracts could be seen and appreciated every spring day at mealtime. Because of the appreciation the homeowner felt for the tree, I did not insist that the tree be put back toward the street.
The installation practice follows the most recent recommendations for tree installation techniques. All trees were maintained primarily with watering for two years (by the homeowner), pruning at installation time to remove only dead or diseased branches and three years later for structural pruning by the arborist, and sometimes an optional fertilizer treatment was made after the roots were established. Wellesley's research has shown that the tree survival rate was 98% after one year and 95% after 5 years. Survival beyond five years was nearly 100% as the trees grew on to reach maturity. Tree removal records indicate that most of the trees on private property survive for 75 – 100 years while those next to the street survive only 40 years on average, in Wellesley.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Utility, Municipal Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA practice credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
By Len Phillips
According to a survey conducted by LinkedIn's Urban Forestry Discussion Group, the urban forestry programs in cities around the country, average a C- in their city tree management programs. One exception to this survey was Wellesley, Massachusetts, where the Park and Tree Division within the Public Works Department is responsible for installing new city trees. Most of the new trees are planted on private property with public funds, as allowed by local and State laws. These laws allow communities to install public trees between the sidewalk and 20 feet from the edge of the public way and Wellesley had adopted this law as a policy. This setback practice has resulted in healthier trees that grow better, faster, and live longer than trees planted next to the street curb. Setback trees receive less damage from exhaust fumes, road salt, and car doors. Plus, their lower branches do not get hit by tall trucks; their upper branches do not grow into the utility wires; and their roots have plenty of good soil to grow in.
Throughout most of the time from 1974 into the 1990's, Wellesley set aside up to $25,000 each year for the installation of new trees. The funds were sufficient for installing an average of 300 trees every year. The trees were required to be an average of 2 inches (5 cm) in trunk diameter. Bare root was required because they were half the cost of the same tree balled and burlapped (B&B), so twice the number of trees could be installed for the funds available.
Tree Selection Process
The ordering of trees for spring planting begins in the autumn prior to the spring installation. The municipal arborist prepares a list of trees to be considered for the next season. The list contains a 50 - 50 mix of flowering trees and shade trees with one evergreen species. Half the trees mature at a large size for street tree installations and the other half are under 25 feet (7m) in height, for installing in combination with large trees or on the side of the street where overhead wires could be a potential problem.
The program placed a great emphasis on selecting and installing the trees bare root. The cost of contracted labor to do the actual installation was also very low because the holes could be dug smaller and the time to install the bare root tree was more than half of the time needed to install a tree B&B. No heavy equipment was needed to place the tree in the hole and the tree roots were stapled to the bottom of the hole, so no time-consuming staking was required. However, some years the contractor brought along a backhoe tractor to dig nice saucer shaped holes.
All the trees that were selected for installation each year were species known to do well in the urban New England environment. The trees selected did not require much maintenance, they were pest and disease resistant, the soils were matched to tree preference, which allowed the roots to grow with a minimum of effort, and the trees were cold and heat tolerant to ensure long-term survival. Every year up to ten new introductions or trees the City wanted to test in our location were added to the list so we could use the best-performing trees in the future.
Obtaining Quotes
Once a plant list was prepared, it was sent to 6 – 8 nurseries known to offer high quality trees, to obtain availability and pricing information for delivery the following spring. Most of the trees were to be quoted at 2" diameter or less and bare root, if possible. A minimum quantity of 10 trees per species was requested to take advantage of quantity discounts. Substitution of size and species or cultivar was allowed at this time only. The nurseries responded with what they expected to have available the following spring.
Using this information, the list was revised according to size, price, species, and quantity of available trees. The revised list was sent back to the nurseries for a final quote. Generally, 3 – 4 nurseries were selected for specific trees. Upon return of the quotes, purchase orders were placed with each nursery. Since so many nurseries were involved, none of the orders exceed the $10,000 threshold above which the state required competitive bidding. Therefore, the timely and expensive bidding process was avoided, and a quote system was permitted.
The same process was undertaken for selecting tree-planting contractors. At least 6 – 7 contractors known to be skilled and knowledgeable in installation techniques for bare root trees were sent quote sheets for installing a given number of trees at each of the sizes indicated on the list of trees selected. The contractors were asked to provide a unit price for installing each size tree. Again, because of the number of contractors and low costs per tree size, none of the contractors exceed the bid limit. In situations where the contractors quote the same price on the same size tree, both were awarded the contract and they split the number of plantings in that size.
With this process completed in the autumn, the budget was set and the orders were placed long before the spring rush, avoiding problems and disappointment with orders that were incomplete or not as desired.
Bidding versus Quotes
On average, the $25,000 budget purchased 300 trees. The average quoted cost of $53 for each tree plus the average quoted cost of $30 to install, totals $83 per bare root tree. (The one year that bidding was required by the city comptroller, only 75 trees could be purchased for the $25,000. The vendors doing the bidding required a fee for program management; they specified expensive B&B trees, 2" diameter minimum size, and union labor contractors to do the installation. Less than ten trees of each species or cultivar were ordered. The average cost per tree in the ground was $333.)
The Wellesley finance director decided that obtaining quotes to purchase different tree species or cultivars as separate items and the installation of different size trees as separate items, rather than bidding the entire package did not violate the bidding laws. He was convinced of this once he saw how the available dollars installed so many more trees by competitive quotes, than the competitive bidding process would allow, it was not in violation of State law.
(This idea was borrowed from the vehicle maintenance garage. They also had to put the purchase of nuts and bolts out to bid until the director indicated that there was no way the number of nuts and bolts needed each year could be predicted. With that example, the competitive quotes for each size nut and bolt did not violate the State bidding laws.)
Planting Plans
Since these trees were installed on private property, the Park and Tree Division's landscape architect consulted with the homeowner to be sure the trees were installed in the right place to enhance the landscape design of the street and the residence. They also believed the homeowner should have a choice of what tree was installed in their yard, so they would develop pride in the tree and feel a part of the entire tree installation program. For the funds available, as many as 30 different tree species were ordered. This gives the resident a wide variety of trees from which to select the tree they wanted in their yard. The program was developed with resident participation as a central goal, along with assurance that the investment in trees would not be wasted. Any left-over trees were planted on public properties such as the parks, schools, conservation areas, streets with no abutting homes, and public buildings.
The Process
The program starts with a list of residents who have heard about the program and would like trees installed on their property. The residents on this waiting list get the first choice of trees each year. The second level of priority occurs along selected streets. Each year the Tree Advisory Committee sets a priority for streets that should get new trees. These streets are then given to the Park and Tree Division who conducts an inventory of the existing trees and selected locations where trees could possibly be installed. The Division prepares planting plans to indicate the potential installation sites.
Once the waiting list was finalized and the planting location plans were accepted by the Tree Advisory Committee, the arborist contacts each homeowner to see if they were interested in having a tree installed in their front yard. If they are, the arborist makes an appointment to visit with them a couple of months prior to the installation and works with the homeowners regarding tree selection and the front yard location for each new tree. The arborist brings a book of photographs and descriptions of each of the trees that will be available. This information helps the owner select trees for their yard that they may not be familiar with. The approximate locations are marked on the lawn with stakes or spray paint. The locations and species were also noted on the street tree plan in case the stake disappears or the spray paint fades.
Installation
When this process was completed, the utility locations were marked, and the trees were delivered to the central maintenance yard where they were stored in wood chip mulch and kept watered in a manner similar to the Missouri Gravel Bed program. When weather conditions were right, the installation contractors were notified to begin. Each day they take only those bare root trees needed for the day and they would plant their trees according to the planting plans. Close supervision was essential to be sure the trees were located and installed correctly. The arborist tells the contractors that “if the tree's bare roots are exposed to sun and wind for 30 seconds, the root hairs will die”. This ensures prompt attention by the contractor when making delivery of the trees to the site as well as during the installation process. The tree roots were kept covered with wood chips or wet canvas on the delivery trucks, covered while the holes were being dug, and watered during and immediately after installation. Once the installation was completed, the trees were stapled to the ground with wood staples made by the Wellesley DPW carpentry shop, mulched, and a few days later the final inspection was made by the arborist. At this inspection, the homeowner was given a letter with the name of the tree and a description of the care the tree should receive. Only once did I find a tree (dogwood) dug up the evening after its installation near the street and moved by the homeowner to a location near the home's dining room window where the bracts could be seen and appreciated every spring day at mealtime. Because of the appreciation the homeowner felt for the tree, I did not insist that the tree be put back toward the street.
The installation practice follows the most recent recommendations for tree installation techniques. All trees were maintained primarily with watering for two years (by the homeowner), pruning at installation time to remove only dead or diseased branches and three years later for structural pruning by the arborist, and sometimes an optional fertilizer treatment was made after the roots were established. Wellesley's research has shown that the tree survival rate was 98% after one year and 95% after 5 years. Survival beyond five years was nearly 100% as the trees grew on to reach maturity. Tree removal records indicate that most of the trees on private property survive for 75 – 100 years while those next to the street survive only 40 years on average, in Wellesley.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Utility, Municipal Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA practice credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Soil for Urban Tree Installations
Edited by Len Phillips
Global warming is underway and one thing that arborists can do is to help alleviate the problem by planting as many trees as possible. When installing trees in an urban landscape such as a plaza, beside a sidewalk, in the street median or tree lawn, or any other location where the existing soil will not support plant growth, it is important to specify and install a soil that meets the cultural needs of the tree species. The following guidelines are for the mixing of a soil that will promote the healthy development of most woody landscape plants. This soil is also suitable for the installation in new planting locations in suburban areas, but is not intended for roof top gardens.
Soil Volume Requirements
The amount of soil available will in large part determine the maximum size that the tree will achieve during its life span. To determine soil volume required, a tree will need about 5 square feet (0.45 s. meters), 3 feet (1 m.) deep of soil area for each square inch (6.5 sq. cm.) of trunk diameter that the tree is anticipated to be at its maximum size. In the urban environment, the essential soil area may need to come from the tree lawn between the street and the sidewalk as well as under and beyond the sidewalk toward private property.
Soil Depth
Tree roots will seldom grow deeper than 3 feet (1 m). To allow trees to grow to their full potential, the soil must be composed of topsoil and installed in layers. A subsoil mix should be installed first if the planting site is deeper than 3 feet and this should be covered with the topsoil mix. When installing layers, the base soil surface should be tilled or scarified with the teeth of an excavator bucket initially to break up any compaction that occurred. Then the topsoil is installed in three or four lifts or layers of less than 12 inches (30 cm) each with a modest compaction between each layer.
Soil Mix
The topsoil may be from either a naturally occurring topsoil or soil that has been mixed to achieve the following specification. Both the top and subsoil should be a sandy loam soil with 50-80% medium and coarse sand (less than 25% fine sand), 5-20% clay, 5-35% silt.
Stones and Rocks
No stones larger than 1 inch (2.5 cm) in the longest dimension should be permitted. Stones ranging from 0.5 to 1 inch (1.25 to 2.5 cm) should not exceed 5% of the soil volume, and gravel ¼ to ½ inches (0.6 to 1.25 cm) should not exceed 5% of the soil volume.
Debris Content
Debris is defined as fragments of brick, concrete, wood, glass, metal, stone and plastic greater than 1 inch in the longest dimension and this debris is not allowed. The total volume of debris less than 1 inch long should not be more than 5% of the total soil volume.
Contaminants
The soil should have no herbicides, heavy metals, biological toxins, or hydrocarbons that will impact plant growth or are at levels exceeding the EPA’s standards for soil contaminants.
Clod Size
Mixed soils often contain soil clods with a high clay content. Smaller soil peds that are less than 1 inch long are desirable from a soil drainage perspective and there is no limit on the amount of these small peds contained in the soil mix. Clods from 1-3 inches (2.5-7.5 cm) should make up less than 10% of the soil volume and clods 3-6 inch (7.5-15 cm) should be less than 5%.
Organic Matter Content
Organic matter (OM) is important for retaining water, maintaining stable soil aggregates, promoting biological diversity and providing nutrients for tree growth. The topsoil shall have 4-6% OM by weight. If additional organic matter is needed, compost can be added to the soil. A well composted leaf mold, yard waste, or wood chip compost can be used as long as there is no more than 10% OM by volume in the compost. No soil mix should contain more than 15% compost by volume so as to avoid settling or subsidence problems. Subsoil should have between 1-3% OM, but higher levels are not detrimental.
Density
Soil density needs to be high enough to avoid settling, yet low enough to allow root growth. Topsoil should have a density of 1.0 to 1.4 grams per centimeter (g/cc) and subsoil 1.2 to 1.5 g/cc. A vibrating plate compactor should be used between lifts to settle the soil. Number of passes required needs to be determined on site, but should be minimal. A starting point is one or two passes of a 20 inch (55 cm) impact plate vibrating compactor on a moist (not wet) soil to achieve the desirable density.
Drainage
Water should readily drain from the soil. Percolation rates of 1-2 inches (2.5-5 cm) per hour are preferred, if irrigation will be installed. A drainage system should be installed if the native subsoil has a drainage rate less than 1 inch (2.5 cm) per hour. Corrugated, slotted pipe should be used for drainage. Slots must only be on the bottom half of the pipe. If pipe has slots on the top, plastic sheeting should be taped to the top to keep soil particles out of the pipe.
The drain pipe should be surrounded with coarse sand and should not be wrapped with filter fabric to avoid future clogging problems. The coarse sand trench should be at least 12 inches (30 cm) wide and 10 inches (25 cm) deep, with the pipe in the center. The pipe must go downhill to an appropriate drainage area.
If the tree installation is occurring in conjunction with a street drainage improvement project, perforated pipe between the street drain and the planting pit will allow the tree to be watered with street runoff water. A second perforated pipe should be installed at the bottom of the tree pit to collect surplus water and that pipe is connected to the municipal storm water drainage system or an appropriate drainage area. This process will also clean the street drainage water as it passes through the planting soil.
Soil pH
Soil pH determines the availability of nutrients in the soil. The exact pH range is dependent on the tree species to be planted. Generally, the most desirable pH range is 5.5-6.6 in humid regions (Eastern North American, western OR, WA and BC) and 6.0 to 7.4 in arid regions (TX, AZ, CA). Optimal pH is highly dependent on the tree species to be planted and should be tested and adjusted based on species prior to planting.
Nutrients
Plant-available nutrients should be tested prior to soil installation. If they are found to be at levels that are listed as “medium” or less on the soil analysis report, the soil should be amended with the appropriate fertilizers. If nitrogen is required, the nitrogen fertilizer shall contain at least 50% of the total N applied in a water insoluble (WIN) form.
Soluble Salt
Soluble salt content shall be less than 2 dS/m.
Water
Water is an essential component of keeping new transplants alive and thriving. Soil moisture should be monitored regularly and irrigation applied when needed to assure adequate moisture. Excess irrigation can also harm plants so over irrigation should be avoided. Installation of soil moisture sensors at the time of soil installation is highly recommended.
With any new planting, the trees and soil moisture should be monitored regularly. Pests can do serious
damage to new transplants and are most easily managed before populations build to damaging levels. An Integrated Pest Management (IPM) program is an effective means for protecting new transplants.
Source
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Utility, Municipal Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA practice credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Edited by Len Phillips
Global warming is underway and one thing that arborists can do is to help alleviate the problem by planting as many trees as possible. When installing trees in an urban landscape such as a plaza, beside a sidewalk, in the street median or tree lawn, or any other location where the existing soil will not support plant growth, it is important to specify and install a soil that meets the cultural needs of the tree species. The following guidelines are for the mixing of a soil that will promote the healthy development of most woody landscape plants. This soil is also suitable for the installation in new planting locations in suburban areas, but is not intended for roof top gardens.
Soil Volume Requirements
The amount of soil available will in large part determine the maximum size that the tree will achieve during its life span. To determine soil volume required, a tree will need about 5 square feet (0.45 s. meters), 3 feet (1 m.) deep of soil area for each square inch (6.5 sq. cm.) of trunk diameter that the tree is anticipated to be at its maximum size. In the urban environment, the essential soil area may need to come from the tree lawn between the street and the sidewalk as well as under and beyond the sidewalk toward private property.
Soil Depth
Tree roots will seldom grow deeper than 3 feet (1 m). To allow trees to grow to their full potential, the soil must be composed of topsoil and installed in layers. A subsoil mix should be installed first if the planting site is deeper than 3 feet and this should be covered with the topsoil mix. When installing layers, the base soil surface should be tilled or scarified with the teeth of an excavator bucket initially to break up any compaction that occurred. Then the topsoil is installed in three or four lifts or layers of less than 12 inches (30 cm) each with a modest compaction between each layer.
Soil Mix
The topsoil may be from either a naturally occurring topsoil or soil that has been mixed to achieve the following specification. Both the top and subsoil should be a sandy loam soil with 50-80% medium and coarse sand (less than 25% fine sand), 5-20% clay, 5-35% silt.
Stones and Rocks
No stones larger than 1 inch (2.5 cm) in the longest dimension should be permitted. Stones ranging from 0.5 to 1 inch (1.25 to 2.5 cm) should not exceed 5% of the soil volume, and gravel ¼ to ½ inches (0.6 to 1.25 cm) should not exceed 5% of the soil volume.
Debris Content
Debris is defined as fragments of brick, concrete, wood, glass, metal, stone and plastic greater than 1 inch in the longest dimension and this debris is not allowed. The total volume of debris less than 1 inch long should not be more than 5% of the total soil volume.
Contaminants
The soil should have no herbicides, heavy metals, biological toxins, or hydrocarbons that will impact plant growth or are at levels exceeding the EPA’s standards for soil contaminants.
Clod Size
Mixed soils often contain soil clods with a high clay content. Smaller soil peds that are less than 1 inch long are desirable from a soil drainage perspective and there is no limit on the amount of these small peds contained in the soil mix. Clods from 1-3 inches (2.5-7.5 cm) should make up less than 10% of the soil volume and clods 3-6 inch (7.5-15 cm) should be less than 5%.
Organic Matter Content
Organic matter (OM) is important for retaining water, maintaining stable soil aggregates, promoting biological diversity and providing nutrients for tree growth. The topsoil shall have 4-6% OM by weight. If additional organic matter is needed, compost can be added to the soil. A well composted leaf mold, yard waste, or wood chip compost can be used as long as there is no more than 10% OM by volume in the compost. No soil mix should contain more than 15% compost by volume so as to avoid settling or subsidence problems. Subsoil should have between 1-3% OM, but higher levels are not detrimental.
Density
Soil density needs to be high enough to avoid settling, yet low enough to allow root growth. Topsoil should have a density of 1.0 to 1.4 grams per centimeter (g/cc) and subsoil 1.2 to 1.5 g/cc. A vibrating plate compactor should be used between lifts to settle the soil. Number of passes required needs to be determined on site, but should be minimal. A starting point is one or two passes of a 20 inch (55 cm) impact plate vibrating compactor on a moist (not wet) soil to achieve the desirable density.
Drainage
Water should readily drain from the soil. Percolation rates of 1-2 inches (2.5-5 cm) per hour are preferred, if irrigation will be installed. A drainage system should be installed if the native subsoil has a drainage rate less than 1 inch (2.5 cm) per hour. Corrugated, slotted pipe should be used for drainage. Slots must only be on the bottom half of the pipe. If pipe has slots on the top, plastic sheeting should be taped to the top to keep soil particles out of the pipe.
The drain pipe should be surrounded with coarse sand and should not be wrapped with filter fabric to avoid future clogging problems. The coarse sand trench should be at least 12 inches (30 cm) wide and 10 inches (25 cm) deep, with the pipe in the center. The pipe must go downhill to an appropriate drainage area.
If the tree installation is occurring in conjunction with a street drainage improvement project, perforated pipe between the street drain and the planting pit will allow the tree to be watered with street runoff water. A second perforated pipe should be installed at the bottom of the tree pit to collect surplus water and that pipe is connected to the municipal storm water drainage system or an appropriate drainage area. This process will also clean the street drainage water as it passes through the planting soil.
Soil pH
Soil pH determines the availability of nutrients in the soil. The exact pH range is dependent on the tree species to be planted. Generally, the most desirable pH range is 5.5-6.6 in humid regions (Eastern North American, western OR, WA and BC) and 6.0 to 7.4 in arid regions (TX, AZ, CA). Optimal pH is highly dependent on the tree species to be planted and should be tested and adjusted based on species prior to planting.
Nutrients
Plant-available nutrients should be tested prior to soil installation. If they are found to be at levels that are listed as “medium” or less on the soil analysis report, the soil should be amended with the appropriate fertilizers. If nitrogen is required, the nitrogen fertilizer shall contain at least 50% of the total N applied in a water insoluble (WIN) form.
Soluble Salt
Soluble salt content shall be less than 2 dS/m.
Water
Water is an essential component of keeping new transplants alive and thriving. Soil moisture should be monitored regularly and irrigation applied when needed to assure adequate moisture. Excess irrigation can also harm plants so over irrigation should be avoided. Installation of soil moisture sensors at the time of soil installation is highly recommended.
With any new planting, the trees and soil moisture should be monitored regularly. Pests can do serious
damage to new transplants and are most easily managed before populations build to damaging levels. An Integrated Pest Management (IPM) program is an effective means for protecting new transplants.
Source
- Smiley, E. Thomas, PhD, “Soil for Urban Tree Planting”, Bartlett Research Laboratory Technical Report
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the 0.5 CEUs toward Certified Arborist, Utility, Municipal Specialist, Tree Worker/Climber, Tree Worker/Aerial Lift, or BCMA practice credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to Merchant' / gibneyCE.com. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website.
*SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.