Seminar #64 from Online Seminars for Municipal Arborists – September / October 2015
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Conifers and the Built Environment
By J. Casey Clapp, Rick W. Harper and H. Dennis Ryan
Urban foresters and arborists have much to consider when it comes to deciding about the tree species that should be planted along community streets and greenways, as well as in landscapes and parks. From wintertime shading to species diversity, and a myriad of considerations in-between, our urban forests require thought and attention to be maintained in a healthy manner and thus provide us with invaluable ecosystem services. Many of these services are vitally important and include carbon sequestration, wildlife habitat, privacy screening, and storm water abatement through the interception of rainfall.
Year-round leaf cover has been shown to provide year-round ecosystem services. The vast majority of coniferous trees are evergreen, and that means that many ecosystem services are offered on a 12-month basis. Many of the benefits derived from deciduous trees, such as pollution absorption, privacy screening, thermal buffering, and rainwater interception, decrease to negligible levels during the leaf-off season. The foliage of evergreen trees, however, continue to offer these benefits throughout the entire year. Evergreens intercept and store nearly 50 percent more storm water, helping to reduce runoff at a time when soils may be frozen and surface water movement may be particularly acute. The evergreen foliage also continually absorbs important urban pollutants like ozone, carbon dioxide, and particulate matter (microscopic dust) during drought conditions and during the winter season, two important periods when ozone is being emitted due to the increased use of energy to cool and warm buildings. In addition to these important ecosystem services being derived year-round, evergreen conifers may add some variety to the built environment.
The Need for Street Tree Diversity
With the vast majority of a city’s street trees being comprised of deciduous trees, it is obvious that urban forests demonstrate a uniformity that is notoriously unsustainable. Urban planting recommendations pertaining to species diversification vary and include the following:
By J. Casey Clapp, Rick W. Harper and H. Dennis Ryan
Urban foresters and arborists have much to consider when it comes to deciding about the tree species that should be planted along community streets and greenways, as well as in landscapes and parks. From wintertime shading to species diversity, and a myriad of considerations in-between, our urban forests require thought and attention to be maintained in a healthy manner and thus provide us with invaluable ecosystem services. Many of these services are vitally important and include carbon sequestration, wildlife habitat, privacy screening, and storm water abatement through the interception of rainfall.
Year-round leaf cover has been shown to provide year-round ecosystem services. The vast majority of coniferous trees are evergreen, and that means that many ecosystem services are offered on a 12-month basis. Many of the benefits derived from deciduous trees, such as pollution absorption, privacy screening, thermal buffering, and rainwater interception, decrease to negligible levels during the leaf-off season. The foliage of evergreen trees, however, continue to offer these benefits throughout the entire year. Evergreens intercept and store nearly 50 percent more storm water, helping to reduce runoff at a time when soils may be frozen and surface water movement may be particularly acute. The evergreen foliage also continually absorbs important urban pollutants like ozone, carbon dioxide, and particulate matter (microscopic dust) during drought conditions and during the winter season, two important periods when ozone is being emitted due to the increased use of energy to cool and warm buildings. In addition to these important ecosystem services being derived year-round, evergreen conifers may add some variety to the built environment.
The Need for Street Tree Diversity
With the vast majority of a city’s street trees being comprised of deciduous trees, it is obvious that urban forests demonstrate a uniformity that is notoriously unsustainable. Urban planting recommendations pertaining to species diversification vary and include the following:
- No more than 10% of any one species in an
urban forest;
- No more than 5% any one species and 10%
of any one genus;
- No more than 10% of any one species,
20% of any one genus, and 30% of any one family in the urban forest.
By simply planting conifers in urban
landscapes, we can help to address this diversity deficit and “spread the
risks” related to insects and diseases that threaten to devastate the urban
tree populations – often one species at a time. We have seen firsthand the
large numbers of urban tree populations that have been lost as a result of
insects and diseases that have included Chestnut Blight (Cryphonectria
parasitica), Dutch Elm Disease (Ophiostoma ulmi), Asian Longhorned
Beetle (Anoplophora glabripennis), and now Emerald Ash Borer (Agrilus
planipennis). The more diverse the composition of an urban forest can be
in terms of tree species, the more resilient it may be in the face of a
disturbance like a pest invasion.
The need for diversification, however, doesn't just stop at the tree species level. Studies have shown that diversity at several different levels across the urban landscape – including spatial distribution, plant functional type, structure, and age class – is of great benefit to the urban ecosystem. These factors all intermingle to help to create a complex urban forest system that supports efficiency and functionality. By adding evergreen conifers to the urban ecosystem, diversity is increased at each of these important levels, thereby lowering the risk of any single disturbance (e.g., snow or ice storm, drought, or a pest outbreak) from devastating large portions of the urban forest by limiting the percentage of trees that could potentially be affected.
Conifers and Wildlife
Another benefit derived from trees with dense, evergreen foliage is the associated wildlife habitat, thermal cover, and food resources that are made available during the winter. This helps to increase the presence of urban wildlife since there is often a dearth of suitable wildlife resources in the urban environment. Several species of birds that overwinter in northern areas use the thermal cover afforded by conifers to take shelter during the harsh months. Birds, squirrels and other small mammals use the cones as food, and many of these same species use the thick foliage for cover during the breeding season.
Design and Function
The basis for proper function is proper design. Urban foresters should strive to create an urban forest network that works as efficiently as possible, avoids major conflicts, provides a high return, and uses the best tools available. Plan your planting for the long-term.
Wintertime shading is a notably important aspect to consider when planting evergreen conifers in the urban landscape and most notably when planting them as street trees. Ice buildup on roads can cause significant issues, so it is necessary to allow for optimal winter sun exposure on streets. Planting evergreen trees on the south side of an east-west oriented street will cause a shadow to be cast over the street during the winter. This conflict may be avoided, however, by planting evergreen species on the north side of the street and deciduous species on the south side. By employing this technique, one can still gain beneficial winter sun exposure. However, shade-tolerant evergreen conifers may be established within the vicinity of a permanent object (i.e. building) that is already casting shade. Because the road is already shaded, the evergreen conifer does not cast further shading, and it does contribute positive ecosystem services. By taking sun exposure and aspect into account, conifers can be included as street trees without causing conflicts during winter.
Green “Screens”
Due to their dense, evergreen foliage, many evergreen conifers can efficiently block sight, sound, and wind. By using evergreen conifers as thermal buffers and wind blocks around a building, the building’s efficiency can be increased by up to 25% by limiting the amount of heat loss due to cold air infiltration, or by the cooling of the building shell via passing wind. Used as audio or visual barriers, evergreen conifers can also help to muffle unwanted road noise from highways and block unsightly views. Salt-tolerant species of conifers can also act as buffers between roads and nearby areas that may be sensitive to road salts. By planting evergreen conifers around freeways, the noise, sight, and salt pollution can be better contained to those areas. Evergreen conifers can also absorb pollution and particulate matter that is emitted from highway traffic and block water spray continuously throughout the year. Though the buffering benefits from evergreen conifers are obvious, they may also be planted as part of a strategy to help decrease the urban heat island effect often associated with urban settings.
Planting evergreen conifers helps to keep small outdoor spaces, or microclimates, cool. By cooling enough of these microclimates throughout the urban environment, the macroclimate may also be influenced positively where the effects of the urban heat island may begin to be addressed.
Conifers and Urban Tree Inventories
According to inventory data from across the United States, conifers appear to be notoriously underrepresented as street trees. Of the trees inventoried in Portland, Oregon (just under 40,000), only 2.2% were determined to be evergreen conifers. Chicago, Illinois featured about 9.1% coniferous street trees, while Boston, Massachusetts had no conifers listed in their top 25 species that comprised 96.7% of their street trees. Minneapolis, Minnesota featured 0.3% conifers, Charlotte, North Carolina 8.5%, and Berkeley, California identified conifers as comprising only 4% of their community tree inventories, respectively. These numbers equate to the simple fact that cities are not taking full advantage of the benefits that may be derived by increasing their numbers of evergreen conifers.
Summary
Urban populations derive numerous personal benefits from urban greenery that include reduced stress and increased quality of life, as well as healthier birth weights for newborns and more productive workplaces in what can potentially be more aesthetically-pleasing communities. Indeed, at no point are the aesthetic benefits of evergreen conifers more apparent then when deciduous leaves have turned brown and the trees themselves have become barren. It is hoped that as evergreen conifers grow to become better recognized as key components of green infrastructure systems that can offer significant returns through their ecosystem services, and that they may then be more readily incorporated into the design and installation of the contemporary urban forest.
By taking into account ‘Right Tree, Right Place,’ as well as the site objectives (for example – rainwater interception, species diversity, micro-climate management, etc.), the urban forester can indeed create a dynamic and diverse infrastructure system: the urban forest of the 21st century that includes a multitude of both deciduous and evergreen coniferous species.
About the Authors:
The need for diversification, however, doesn't just stop at the tree species level. Studies have shown that diversity at several different levels across the urban landscape – including spatial distribution, plant functional type, structure, and age class – is of great benefit to the urban ecosystem. These factors all intermingle to help to create a complex urban forest system that supports efficiency and functionality. By adding evergreen conifers to the urban ecosystem, diversity is increased at each of these important levels, thereby lowering the risk of any single disturbance (e.g., snow or ice storm, drought, or a pest outbreak) from devastating large portions of the urban forest by limiting the percentage of trees that could potentially be affected.
Conifers and Wildlife
Another benefit derived from trees with dense, evergreen foliage is the associated wildlife habitat, thermal cover, and food resources that are made available during the winter. This helps to increase the presence of urban wildlife since there is often a dearth of suitable wildlife resources in the urban environment. Several species of birds that overwinter in northern areas use the thermal cover afforded by conifers to take shelter during the harsh months. Birds, squirrels and other small mammals use the cones as food, and many of these same species use the thick foliage for cover during the breeding season.
Design and Function
The basis for proper function is proper design. Urban foresters should strive to create an urban forest network that works as efficiently as possible, avoids major conflicts, provides a high return, and uses the best tools available. Plan your planting for the long-term.
Wintertime shading is a notably important aspect to consider when planting evergreen conifers in the urban landscape and most notably when planting them as street trees. Ice buildup on roads can cause significant issues, so it is necessary to allow for optimal winter sun exposure on streets. Planting evergreen trees on the south side of an east-west oriented street will cause a shadow to be cast over the street during the winter. This conflict may be avoided, however, by planting evergreen species on the north side of the street and deciduous species on the south side. By employing this technique, one can still gain beneficial winter sun exposure. However, shade-tolerant evergreen conifers may be established within the vicinity of a permanent object (i.e. building) that is already casting shade. Because the road is already shaded, the evergreen conifer does not cast further shading, and it does contribute positive ecosystem services. By taking sun exposure and aspect into account, conifers can be included as street trees without causing conflicts during winter.
Green “Screens”
Due to their dense, evergreen foliage, many evergreen conifers can efficiently block sight, sound, and wind. By using evergreen conifers as thermal buffers and wind blocks around a building, the building’s efficiency can be increased by up to 25% by limiting the amount of heat loss due to cold air infiltration, or by the cooling of the building shell via passing wind. Used as audio or visual barriers, evergreen conifers can also help to muffle unwanted road noise from highways and block unsightly views. Salt-tolerant species of conifers can also act as buffers between roads and nearby areas that may be sensitive to road salts. By planting evergreen conifers around freeways, the noise, sight, and salt pollution can be better contained to those areas. Evergreen conifers can also absorb pollution and particulate matter that is emitted from highway traffic and block water spray continuously throughout the year. Though the buffering benefits from evergreen conifers are obvious, they may also be planted as part of a strategy to help decrease the urban heat island effect often associated with urban settings.
Planting evergreen conifers helps to keep small outdoor spaces, or microclimates, cool. By cooling enough of these microclimates throughout the urban environment, the macroclimate may also be influenced positively where the effects of the urban heat island may begin to be addressed.
Conifers and Urban Tree Inventories
According to inventory data from across the United States, conifers appear to be notoriously underrepresented as street trees. Of the trees inventoried in Portland, Oregon (just under 40,000), only 2.2% were determined to be evergreen conifers. Chicago, Illinois featured about 9.1% coniferous street trees, while Boston, Massachusetts had no conifers listed in their top 25 species that comprised 96.7% of their street trees. Minneapolis, Minnesota featured 0.3% conifers, Charlotte, North Carolina 8.5%, and Berkeley, California identified conifers as comprising only 4% of their community tree inventories, respectively. These numbers equate to the simple fact that cities are not taking full advantage of the benefits that may be derived by increasing their numbers of evergreen conifers.
Summary
Urban populations derive numerous personal benefits from urban greenery that include reduced stress and increased quality of life, as well as healthier birth weights for newborns and more productive workplaces in what can potentially be more aesthetically-pleasing communities. Indeed, at no point are the aesthetic benefits of evergreen conifers more apparent then when deciduous leaves have turned brown and the trees themselves have become barren. It is hoped that as evergreen conifers grow to become better recognized as key components of green infrastructure systems that can offer significant returns through their ecosystem services, and that they may then be more readily incorporated into the design and installation of the contemporary urban forest.
By taking into account ‘Right Tree, Right Place,’ as well as the site objectives (for example – rainwater interception, species diversity, micro-climate management, etc.), the urban forester can indeed create a dynamic and diverse infrastructure system: the urban forest of the 21st century that includes a multitude of both deciduous and evergreen coniferous species.
About the Authors:
- J. Casey Clapp, MS, is an ISA Certified
Arborist currently working as a consulting arborist in Seattle, WA.
- Rick W. Harper, BCMA, is the Extension
Assistant Professor of Urban & Community Forestry in the
Arboriculture/Urban Forestry Program at UMass Amherst.
- H. Dennis Ryan, Ed.D., is a Professor
of Arboriculture & Urban Forestry and Coordinator of the Arboriculture
& Urban Forestry Program at UMass Amherst.
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Conifers for the City
Edited by Len Phillips
Conifers are important fixtures in North American and European landscapes. Because many conifers have foliage year-round, they are particularly adept at screening objectionable views, reducing glare from sunlight or artificial light, redirecting wind, controlling the movements of people, muffling noise, and preventing erosion. Their large size, low-branching habit, and dense foliage often disqualifies them for street tree duty, but they are effective when integrated into windbreak plantings, city parks, town squares, golf courses, and other spacious grounds within a city.
Municipal arborists and other landscape professionals planning to add conifers to a site should consider the species listed below. Dwarf and slow growing forms of the trees mentioned below are also available for use on sites that cannot accommodate large-growing specimens. Conifers may not be appropriate for every landscape situation, but when given ample room to grow, protected from drought, excess moisture, de-icing salt, and mechanical damage, these valuable woody plants can have long and useful lives in the city.
Fir – Abies spp.
There are about 50 species of Abies and they grow thought out the Northern Temperate Zone around the world, reaching from the Arctic Circle to the Topical Zone in Central America. Young trees tend to be symmetrical, uniform and conical, maturing into extremely large trees. In general, firs require moist, well-drained, acid soil and high atmospheric moisture coupled with cool summer temperatures. Only a few species are capable of tolerating hot, dry summers, common in many regions of Canada and the United States (US). They are most appropriately located in full sun.
White fir - Abies concolor has a mature height of 30 – 50 feet and up to 100 feet in ideal locations. They have a mature spread of 15 to 30 feet. The growth habit is considered conical and branches to the base. The needles are grayish green to silvery blue-green and give off a citrus odor when crushed. This tree prefers well-drained soils. If they are planted in clay soils, prepare a wide, shallow hole and avoid planting in areas that tend to remain wet. Photo
Larch – Larix spp.
The genus Larix consists of 16 species and hybrids. It is one of the few conifers featuring deciduous needles. In general larches prefer well-drained soils with ample moisture and sunny locations.
European larch – Larix decidua has a mature height of 70 to 75 feet tall and up to 100 feet in ideal locations. They have a mature spread of 25 to 35 feet. The growth habit is considered pyramidal with horizontal branches. The tree becomes irregular with age. The needles are bright green when young, become deep green in summer and turn yellow gold in the fall. The European larch is more tolerant of the urban landscape than the native American larch. It is a very effective design feature when mass planted in groves. Photo
Dawn redwood – Metasequoia glyptostroboides
The history of dawn redwood dates back to the age when dinosaurs were on the brink of extinction. After an absence of 15 million years, the tree was introduced to North America in the late 1940’s and now thrives under cultivation in the US. Dawn redwood is a fast growing conifer that prefers moist well-drained, slightly acidic soil, and full sun. The tree can be grown as far north as USDA hardiness zone 5.
Dawn redwood has a mature height of 70 to 100 feet tall. They have a mature spread of 25 to 40 feet. The growth habit is considered pyramidal with a single straight trunk. The needles are bright green in summer and turn to orange-brown or red-brown in the fall. The dawn redwood is a deciduous conifer and frost damage can be a problem in low-lying areas. The tree is essentially pest free since all the pests and diseases that attacked this tree died off with the dinosaurs. Photo
Spruce – Picea spp.
The genus Picea consists of up to 40 species. The tree is grown exclusively in the cooler regions of the Northern Hemisphere. In North America they grow above the Arctic Circle and extend south into Mexico. Spruces are relatively sensitive to air pollution and drought, but tolerate shade better than most other conifers. Their ability to withstand extreme cold is legendary.
Norway Spruce – Picea abies has a mature height of 40 to 60 feet tall and up to 100 feet in ideal locations. They have a mature spread of 25 to 35 feet. The growth habit is considered pyramidal with pendulous branches. The needles are bright green when young, become dark green as they mature in summer. Native to Northern and Central Europe, Norway spruce grows faster than many spruces native to North America. Photo
White Spruce – Picea glauca has a mature height of 40 to 60 feet tall. They have a mature spread of 10 to 20 feet. The growth habit is considered pyramidal, compact, and regular. The needles are glaucous green. Crushing the foliage of white spruce releases a musky odor that has earned it the nickname of cat or skunk spruce. Photo
Serbian Spruce – Picea omorika has a mature height of 50 to 60 feet tall. They have a mature spread of 20 to 25 feet. The growth habit is considered narrow and pyramidal. The needles are glossy and dark green above, glaucous white below. Although it is quite cold hardy, the Serbian spruce should be sited where it will receive protection from desiccating winter winds. Photo
Colorado Spruce – Picea pungens has a mature height of 30 to 60 feet tall and up to 100 feet in ideal locations. They have a mature spread of 20 to 30 feet. The growth habit is considered regular, narrow to broadly pyramidal with horizontal stiff branches to the ground. The needles are variable gray-green to blue-green. The tree was discovered near Pike’s Peak in 1862. Colorado spruce is probably the best known and the most frequently planted spruce by arborists today. Photo
Pine – Pinus spp.
Of all the needle-type conifers, pines show the greatest diversity of habit distribution and ornamental features. Approximately 90 species are distributed throughout the Northern Hemisphere. Most are large trees. However, several are shrubby over their native range. Generally pines are considered more tolerant of adverse soil and climatic conditions than species of Picea and Abies. Most prefer full sun.
Lacebark Pine – Pinus bungeana has a mature height of 30 to 50 feet tall. They have a mature spread of 20 to 35 feet. The growth habit is considered pyramidal to round. The tree becomes open and picturesque with age. The needles are lustrous medium to dark green. The bark has exfoliating patches with irregular whitish or brownish areas interspersed. On very old trees the bark on the trunk becomes milk-white and exfoliates in flakes. Photo
Swiss Stone Pine – Pinus cembra has a mature height of 30 to 40 feet tall. They have a mature spread of 15 to 25 feet. The growth habit is considered dense and columnar in youth; open and flat-topped at maturity. The needles are dark green with bluish-white stomatic lines. Swiss stone pine is an excellent ornamental pine but somewhat slow growing. Photo
Korean Pine – Pinus koraiensis has a mature height of 30 to 40 feet tall. They have a mature spread of 15 to 20 feet. The growth habit is considered loose pyramidal. The needles are bluish green. The Korean pine is very adaptable and cold hardy, but rather difficult to find in the nursery trade. Photo
Eastern White Pine – Pinus strobus has a mature height of 50 to 80 feet tall and up to 150 feet in ideal locations. They have a mature spread of 35 to 50 feet. The growth habit is considered pyramidal when young, open and picturesque at maturity. . The needles are bluish green. The Eastern white pine is intolerant of de-icing salts and compacted soils, and frequently suffers “winter burn” on exposed sites. Photo
Scots (Scotch) Pine – Pinus sylvestris has a mature height of 30 to 60 feet tall and up to 90 feet in ideal locations. They have a mature spread of 30 to 40 feet. The growth habit is considered irregular pyramidal when young, wide-spreading or flat-topped at maturity. The needles are bluish green and become yellow-green in winter. The Scots white pine is susceptible to pine wilt resulting from an infestation by the pine wood nematode. This pest has become a significant problem on this pine in the US Midwest and limits the future usefulness of this tree in the city. Photo
Douglas Fir – Pseudotsuga menziesii
Douglas fir is one of the most wide-ranging conifers of western North America, extending from Central British Columbia southward through the Pacific Northwest into the Sierra Nevada and Coast Range mountains of California. Inland populations that inhabit the Rocky Mountains from Alberta to New Mexico are considered a distinct variety, called Colorado Douglas Fir (Pseudotsuga menziesii var. glauca). This variety is smaller and hardier than stock from the Pacific Northwest. Photo
The trunk of the Douglas fir retains its massive girth for much of its height, tapering just below the top of the crown. The tree differs in botanical detail from the true firs. Needles are blunt-tipped and flat and each is twisted at its base at the point of attachment to the stem. The needles occur around the stem, yet the twisted basses orient the majority of needles in one plant. The characteristic pendulous cones with their conspicuous bracts allow for easy identification of this tree.
Douglas fir has a mature height of 40 to 80 feet tall and up to 150 feet in ideal locations. They have a mature spread of 20 to 30 feet. The growth habit is considered pyramidal with stiff branches. The needles are bluish green. Photo
Baldcypress – Taxodium distchum
Baldcypress is a deciduous conifer whose native range of wetlands in the US Southeast is a small expression of the range over which the tree can be planted. The natural range is primarily in USDA hardiness zones 8 and 9 but will grow as far north as zone 4. The tree has thin bark and is easily damaged by fire, so it has found survival in swamp lands. Baldcypress is ideally suited for planting in poorly drained areas and will withstand long periods of flooding. It will also do quite well on dry sites if it is watered frequently in its youth. Baldcypress is remarkably tolerant of urban conditions, but may experience chlorosis on very alkaline soils.
Baldcypress has a mature height of 50 to 70 feet tall. They have a mature spread of 20 to 30 feet. The growth habit is considered pyramidal with horizontal branches. The needles are sage green in summer and turn orange brown in fall. Photo
Eastern Arborvitae – Thuja occidentalis
The genus Thuja constitutes a major group of small to medium size conifers. Five species in cultivation are native in North America and Eastern Asia. However, only Thuja occidentalis and its many selections are hardy in the colder regions of Canada and the US. They are used extensively in the landscape as accent plants, hedges, windbreaks, screens and foundation plants. When planted in fertile, well-drained moist soil, in open and sunny locations, arborvitaes perform well and have few problems with insects or disease. They tolerate partial shade and alkaline soils, however, arborvitae are not drought tolerant.
Arborvitae has a mature height of 20 to 30 feet tall. They have a mature spread of 10 to 15 feet. The growth habit is considered dense, broadly pyramidal with branches that start at the ground. The needles are dark green in summer and turn yellowish green in winter. Photo
Eastern Hemlock – Tsuga canadensis
The genus Tsuga consists of 10 species of conifers. Hemlocks prefer good drainage and cool soils with adequate moisture. They will perform poorly under hot dry conditions. They will withstand full shade however, partial shade is preferable and best growth is attained in full sunlight. They are intolerant of air pollution and de-icing salt spray. Hemlocks can withstand heavy pruning and are often used as a neatly trimmed hedge.
Hemlock has a mature height of 40 to 70 feet tall. They have a mature spread of 25 to 35 feet. The growth habit is considered pyramidal. The needles are dark glossy green in summer. Photo
Conifers with evergreen foliage provide a beautiful and functional framework for the municipal landscape. As focal points in the winter or as backdrops for flowering trees and shrubs in summer, conifers unify a landscape lending continuity to sometimes disparate elements. As you evaluate your landscape in winter, look for areas that could benefit from one or several of these useful woody plants.
Source
Edited by Len Phillips
Conifers are important fixtures in North American and European landscapes. Because many conifers have foliage year-round, they are particularly adept at screening objectionable views, reducing glare from sunlight or artificial light, redirecting wind, controlling the movements of people, muffling noise, and preventing erosion. Their large size, low-branching habit, and dense foliage often disqualifies them for street tree duty, but they are effective when integrated into windbreak plantings, city parks, town squares, golf courses, and other spacious grounds within a city.
Municipal arborists and other landscape professionals planning to add conifers to a site should consider the species listed below. Dwarf and slow growing forms of the trees mentioned below are also available for use on sites that cannot accommodate large-growing specimens. Conifers may not be appropriate for every landscape situation, but when given ample room to grow, protected from drought, excess moisture, de-icing salt, and mechanical damage, these valuable woody plants can have long and useful lives in the city.
Fir – Abies spp.
There are about 50 species of Abies and they grow thought out the Northern Temperate Zone around the world, reaching from the Arctic Circle to the Topical Zone in Central America. Young trees tend to be symmetrical, uniform and conical, maturing into extremely large trees. In general, firs require moist, well-drained, acid soil and high atmospheric moisture coupled with cool summer temperatures. Only a few species are capable of tolerating hot, dry summers, common in many regions of Canada and the United States (US). They are most appropriately located in full sun.
White fir - Abies concolor has a mature height of 30 – 50 feet and up to 100 feet in ideal locations. They have a mature spread of 15 to 30 feet. The growth habit is considered conical and branches to the base. The needles are grayish green to silvery blue-green and give off a citrus odor when crushed. This tree prefers well-drained soils. If they are planted in clay soils, prepare a wide, shallow hole and avoid planting in areas that tend to remain wet. Photo
Larch – Larix spp.
The genus Larix consists of 16 species and hybrids. It is one of the few conifers featuring deciduous needles. In general larches prefer well-drained soils with ample moisture and sunny locations.
European larch – Larix decidua has a mature height of 70 to 75 feet tall and up to 100 feet in ideal locations. They have a mature spread of 25 to 35 feet. The growth habit is considered pyramidal with horizontal branches. The tree becomes irregular with age. The needles are bright green when young, become deep green in summer and turn yellow gold in the fall. The European larch is more tolerant of the urban landscape than the native American larch. It is a very effective design feature when mass planted in groves. Photo
Dawn redwood – Metasequoia glyptostroboides
The history of dawn redwood dates back to the age when dinosaurs were on the brink of extinction. After an absence of 15 million years, the tree was introduced to North America in the late 1940’s and now thrives under cultivation in the US. Dawn redwood is a fast growing conifer that prefers moist well-drained, slightly acidic soil, and full sun. The tree can be grown as far north as USDA hardiness zone 5.
Dawn redwood has a mature height of 70 to 100 feet tall. They have a mature spread of 25 to 40 feet. The growth habit is considered pyramidal with a single straight trunk. The needles are bright green in summer and turn to orange-brown or red-brown in the fall. The dawn redwood is a deciduous conifer and frost damage can be a problem in low-lying areas. The tree is essentially pest free since all the pests and diseases that attacked this tree died off with the dinosaurs. Photo
Spruce – Picea spp.
The genus Picea consists of up to 40 species. The tree is grown exclusively in the cooler regions of the Northern Hemisphere. In North America they grow above the Arctic Circle and extend south into Mexico. Spruces are relatively sensitive to air pollution and drought, but tolerate shade better than most other conifers. Their ability to withstand extreme cold is legendary.
Norway Spruce – Picea abies has a mature height of 40 to 60 feet tall and up to 100 feet in ideal locations. They have a mature spread of 25 to 35 feet. The growth habit is considered pyramidal with pendulous branches. The needles are bright green when young, become dark green as they mature in summer. Native to Northern and Central Europe, Norway spruce grows faster than many spruces native to North America. Photo
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White Spruce – Picea glauca has a mature height of 40 to 60 feet tall. They have a mature spread of 10 to 20 feet. The growth habit is considered pyramidal, compact, and regular. The needles are glaucous green. Crushing the foliage of white spruce releases a musky odor that has earned it the nickname of cat or skunk spruce. Photo
Serbian Spruce – Picea omorika has a mature height of 50 to 60 feet tall. They have a mature spread of 20 to 25 feet. The growth habit is considered narrow and pyramidal. The needles are glossy and dark green above, glaucous white below. Although it is quite cold hardy, the Serbian spruce should be sited where it will receive protection from desiccating winter winds. Photo
Colorado Spruce – Picea pungens has a mature height of 30 to 60 feet tall and up to 100 feet in ideal locations. They have a mature spread of 20 to 30 feet. The growth habit is considered regular, narrow to broadly pyramidal with horizontal stiff branches to the ground. The needles are variable gray-green to blue-green. The tree was discovered near Pike’s Peak in 1862. Colorado spruce is probably the best known and the most frequently planted spruce by arborists today. Photo
Pine – Pinus spp.
Of all the needle-type conifers, pines show the greatest diversity of habit distribution and ornamental features. Approximately 90 species are distributed throughout the Northern Hemisphere. Most are large trees. However, several are shrubby over their native range. Generally pines are considered more tolerant of adverse soil and climatic conditions than species of Picea and Abies. Most prefer full sun.
Lacebark Pine – Pinus bungeana has a mature height of 30 to 50 feet tall. They have a mature spread of 20 to 35 feet. The growth habit is considered pyramidal to round. The tree becomes open and picturesque with age. The needles are lustrous medium to dark green. The bark has exfoliating patches with irregular whitish or brownish areas interspersed. On very old trees the bark on the trunk becomes milk-white and exfoliates in flakes. Photo
Swiss Stone Pine – Pinus cembra has a mature height of 30 to 40 feet tall. They have a mature spread of 15 to 25 feet. The growth habit is considered dense and columnar in youth; open and flat-topped at maturity. The needles are dark green with bluish-white stomatic lines. Swiss stone pine is an excellent ornamental pine but somewhat slow growing. Photo
Korean Pine – Pinus koraiensis has a mature height of 30 to 40 feet tall. They have a mature spread of 15 to 20 feet. The growth habit is considered loose pyramidal. The needles are bluish green. The Korean pine is very adaptable and cold hardy, but rather difficult to find in the nursery trade. Photo
Eastern White Pine – Pinus strobus has a mature height of 50 to 80 feet tall and up to 150 feet in ideal locations. They have a mature spread of 35 to 50 feet. The growth habit is considered pyramidal when young, open and picturesque at maturity. . The needles are bluish green. The Eastern white pine is intolerant of de-icing salts and compacted soils, and frequently suffers “winter burn” on exposed sites. Photo
Scots (Scotch) Pine – Pinus sylvestris has a mature height of 30 to 60 feet tall and up to 90 feet in ideal locations. They have a mature spread of 30 to 40 feet. The growth habit is considered irregular pyramidal when young, wide-spreading or flat-topped at maturity. The needles are bluish green and become yellow-green in winter. The Scots white pine is susceptible to pine wilt resulting from an infestation by the pine wood nematode. This pest has become a significant problem on this pine in the US Midwest and limits the future usefulness of this tree in the city. Photo
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Douglas Fir – Pseudotsuga menziesii
Douglas fir is one of the most wide-ranging conifers of western North America, extending from Central British Columbia southward through the Pacific Northwest into the Sierra Nevada and Coast Range mountains of California. Inland populations that inhabit the Rocky Mountains from Alberta to New Mexico are considered a distinct variety, called Colorado Douglas Fir (Pseudotsuga menziesii var. glauca). This variety is smaller and hardier than stock from the Pacific Northwest. Photo
The trunk of the Douglas fir retains its massive girth for much of its height, tapering just below the top of the crown. The tree differs in botanical detail from the true firs. Needles are blunt-tipped and flat and each is twisted at its base at the point of attachment to the stem. The needles occur around the stem, yet the twisted basses orient the majority of needles in one plant. The characteristic pendulous cones with their conspicuous bracts allow for easy identification of this tree.
Douglas fir has a mature height of 40 to 80 feet tall and up to 150 feet in ideal locations. They have a mature spread of 20 to 30 feet. The growth habit is considered pyramidal with stiff branches. The needles are bluish green. Photo
Baldcypress – Taxodium distchum
Baldcypress is a deciduous conifer whose native range of wetlands in the US Southeast is a small expression of the range over which the tree can be planted. The natural range is primarily in USDA hardiness zones 8 and 9 but will grow as far north as zone 4. The tree has thin bark and is easily damaged by fire, so it has found survival in swamp lands. Baldcypress is ideally suited for planting in poorly drained areas and will withstand long periods of flooding. It will also do quite well on dry sites if it is watered frequently in its youth. Baldcypress is remarkably tolerant of urban conditions, but may experience chlorosis on very alkaline soils.
Baldcypress has a mature height of 50 to 70 feet tall. They have a mature spread of 20 to 30 feet. The growth habit is considered pyramidal with horizontal branches. The needles are sage green in summer and turn orange brown in fall. Photo
Eastern Arborvitae – Thuja occidentalis
The genus Thuja constitutes a major group of small to medium size conifers. Five species in cultivation are native in North America and Eastern Asia. However, only Thuja occidentalis and its many selections are hardy in the colder regions of Canada and the US. They are used extensively in the landscape as accent plants, hedges, windbreaks, screens and foundation plants. When planted in fertile, well-drained moist soil, in open and sunny locations, arborvitaes perform well and have few problems with insects or disease. They tolerate partial shade and alkaline soils, however, arborvitae are not drought tolerant.
Arborvitae has a mature height of 20 to 30 feet tall. They have a mature spread of 10 to 15 feet. The growth habit is considered dense, broadly pyramidal with branches that start at the ground. The needles are dark green in summer and turn yellowish green in winter. Photo
Eastern Hemlock – Tsuga canadensis
The genus Tsuga consists of 10 species of conifers. Hemlocks prefer good drainage and cool soils with adequate moisture. They will perform poorly under hot dry conditions. They will withstand full shade however, partial shade is preferable and best growth is attained in full sunlight. They are intolerant of air pollution and de-icing salt spray. Hemlocks can withstand heavy pruning and are often used as a neatly trimmed hedge.
Hemlock has a mature height of 40 to 70 feet tall. They have a mature spread of 25 to 35 feet. The growth habit is considered pyramidal. The needles are dark glossy green in summer. Photo
Conifers with evergreen foliage provide a beautiful and functional framework for the municipal landscape. As focal points in the winter or as backdrops for flowering trees and shrubs in summer, conifers unify a landscape lending continuity to sometimes disparate elements. As you evaluate your landscape in winter, look for areas that could benefit from one or several of these useful woody plants.
Source
- Iles, Jeff, “A Conifer Sampler”, City Trees, September/October 1996.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the .5 CEUs toward Certified Arborist, Municipal Specialist, or BCMA science credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to 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.
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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.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the .5 CEUs toward Certified Arborist, Municipal Specialist, or BCMA science credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to 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 #64
By Len Phillips
The City Slicker Birch is a selection that is very tolerant of heat and drought. This tree is a fast-growing and hardy for streetscapes and landscape settings. This information has been gathered from the personal observations of the author, living in Massachusetts, Zone 6, and information provided by J. Frank Schmidt & Son nursery.
Trade Name: City Slicker Birch
Botanical Name: Betula nigra ‘Whit XXV’
Plant Patent: PP # 16573
Parentage: Selected from a native stand in Oklahoma by Carl Whitcomb
Family: Betulaceae
Year of Introduction: 2004
Height: 30' – 50'
Spread: 25’
Form: Broadly pyramidal in youth becoming oval with age
Bloom Period: Early spring just before leaves emerge
Flower: Male and female catkins on the same tree
Fruit: Hanging tan cones
Summer Foliage: Glossy dark green, gray pubescence underneath
Autumn Foliage: Golden yellow
Winter Color: Bark provides winter interest
Bark: Bark is typical of river birch but peals away in late summer through winter to reveal unusual creamy white bark inner bark
Habitat: Eastern half of United States, west to Oklahoma
Culture: Native to stream banks and wet areas, tolerates shade
Hardiness Zone: 5 – 9
Growth Rate: Vigorous, full size in 20 years
Pest Resistance: Resistant to bronze birch borer and leaf-spot disease
Storm Resistance: Good
Salt Resistance: Fair to poor
Planting: B&B or tree spade is best, bare root is difficult
Pruning: May be grown as a single stem or clump, do not prune when sap is flowing
Propagating: Made by rooting softwood cuttings in early summer
Design Uses: Specimen for lawn or park, street, and residential locations. It is especially desirable in front of a group of evergreens.
Companions: Use with perennial or evergreen ground covers planted the year after planting the tree
Other Comments: This true river birch rivals B. papyrifera and other white-barked beauties and it has an increased tolerance of heat and drought.
Photo: J. Frank Schmidt & Son Co.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the .5 CEUs toward Certified Arborist, Utility Specialist, Municipal Specialist, Tree Worker Specialist, Aerial Lift Specialist, or BCMA science credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to gibneyCE.com’. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website. *SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
By Len Phillips
The City Slicker Birch is a selection that is very tolerant of heat and drought. This tree is a fast-growing and hardy for streetscapes and landscape settings. This information has been gathered from the personal observations of the author, living in Massachusetts, Zone 6, and information provided by J. Frank Schmidt & Son nursery.
Trade Name: City Slicker Birch
Botanical Name: Betula nigra ‘Whit XXV’
Plant Patent: PP # 16573
Parentage: Selected from a native stand in Oklahoma by Carl Whitcomb
Family: Betulaceae
Year of Introduction: 2004
Height: 30' – 50'
Spread: 25’
Form: Broadly pyramidal in youth becoming oval with age
Bloom Period: Early spring just before leaves emerge
Flower: Male and female catkins on the same tree
Fruit: Hanging tan cones
Summer Foliage: Glossy dark green, gray pubescence underneath
Autumn Foliage: Golden yellow
Winter Color: Bark provides winter interest
Bark: Bark is typical of river birch but peals away in late summer through winter to reveal unusual creamy white bark inner bark
Habitat: Eastern half of United States, west to Oklahoma
Culture: Native to stream banks and wet areas, tolerates shade
Hardiness Zone: 5 – 9
Growth Rate: Vigorous, full size in 20 years
Pest Resistance: Resistant to bronze birch borer and leaf-spot disease
Storm Resistance: Good
Salt Resistance: Fair to poor
Planting: B&B or tree spade is best, bare root is difficult
Pruning: May be grown as a single stem or clump, do not prune when sap is flowing
Propagating: Made by rooting softwood cuttings in early summer
Design Uses: Specimen for lawn or park, street, and residential locations. It is especially desirable in front of a group of evergreens.
Companions: Use with perennial or evergreen ground covers planted the year after planting the tree
Other Comments: This true river birch rivals B. papyrifera and other white-barked beauties and it has an increased tolerance of heat and drought.
Photo: J. Frank Schmidt & Son Co.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the .5 CEUs toward Certified Arborist, Utility Specialist, Municipal Specialist, Tree Worker Specialist, Aerial Lift Specialist, or BCMA science credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to gibneyCE.com’. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website. *SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Invasive Tree Pests – Tips from the Field
By Rob Gorden
Managing invasive insects and diseases is of great importance to arborists and to their communities. While native trees have co-evolved with native tree pests reaching equilibrium, new pests and climate change have altered the norm. Native plant species are dying due to pests introduced from other countries, or the
pest damage is enhanced by changing climate trends, including heat and drought.
Invasive species cause environmental harm, native species dislocation, and potential harm to humans and other native species. We must be better prepared with systems and processes to address invasive species and with our response when they arrive.
Invasive Species Introduction
Invasive species are primarily introduced through the action of humans. In 2010 there were 456 invasive insect species in the US. That number has grown by 46 new species in the last five years. Some invasives include, but are not limited to, are:
By Rob Gorden
Managing invasive insects and diseases is of great importance to arborists and to their communities. While native trees have co-evolved with native tree pests reaching equilibrium, new pests and climate change have altered the norm. Native plant species are dying due to pests introduced from other countries, or the
pest damage is enhanced by changing climate trends, including heat and drought.
Invasive species cause environmental harm, native species dislocation, and potential harm to humans and other native species. We must be better prepared with systems and processes to address invasive species and with our response when they arrive.
Invasive Species Introduction
Invasive species are primarily introduced through the action of humans. In 2010 there were 456 invasive insect species in the US. That number has grown by 46 new species in the last five years. Some invasives include, but are not limited to, are:
- Emerald Ash Borer (EAB), the most
destructive tree pest ever brought to the US, was identified in 2002. New infestations may spread up to 14 miles
annually.
- Gypsy Moth, which went through New England in the
1980's, were eventually controlled by fungi, wasps, and viruses.
Other invaders include:
- Rugose Spiraling Whitefly in the
southeast;
- Hemlock Woolly Adelgid(HWA);
- Japanese Beetle;
- Pinewood Nematode;
- Polyphagous Shot Hole Borer, which
attacks 200 species of trees including Sycamore, Avocado, and Sweet Gum in
California.
Effects of Climate Change
Our changing climate has allowed native and non-native pests to impact broader regions, to attack previously unaffected tree species, and to obtain highly destructive populations. Examples include the Mountain Pine Beetle, which has killed more trees than wildfires; Spruce Beetle; Gold Spotted Oak Borer; Sudden Oak Death; and HWA. Increasing moisture in the east has amplified the severity of leaf diseases, needle casts, and assorted blights. Droughts in the west weaken native trees, permitting explosive insect damage, as is now evident with significant new attacks by Western Pine Beetle in California.
Solutions
The scientific community studying these invasive pests shoulders the burden of identifying each pest and its life cycle; and then determining how to prevent them from destroying native and urban forests. The challenges include research-funding, as well as limitations and delay in recognizing that a new pest has arrived. Pests have a very specific annual life cycle which must be understood. Experimentation with suitable treatment options and methods require years to reach scientifically verifiable conclusions, while destruction continues unabated.
The USDA – APHIS (Animal and Plant Health Inspection Service) is the first line of defense to prevent invasives from spreading within the US. Their role is to eradicate these pests, not to manage them. If APHIS demonstrates success with containment and eradication, control remains with the agency. If the pest can not be eliminated, then management of the pest defers to local government, even if federal regulations and quarantines continue. The Asian Longhorned Beetle (ALB) program has been one of APHIS’s biggest successes. APHIS has treated 1.2 million trees against ALB and removed many infested trees, eradicating it in several state outbreaks.
The Emerald Ash Borer’s life cycle makes detection difficult, and APHIS could not stop its spread. Quarantines were imposed, but its ability to hide in firewood means we are still enhancing its spread. It has hitchhiked across two-thirds of the U.S. in just 18 years. Enormous resources are applied to set up, manage, and educate people on the “quarantine” for each new pest.
Far less money is directed towards educating citizens and professionals on practical solutions to preserve urban forests. The consequence has been enormous delays in the implementation of practical and timely solutions. This delay amplifies costs to local municipalities and private citizens seeking to preserve their urban forests.
Role of Government
State and local governments are designated to address wide reaching and devastating circumstances like floods, storms, and fires. However, naturally occurring invasive pest disasters are often beyond the scope of their expertise. When APHIS disconnected from the effort to eradicate EAB, the interpretation was “nothing can be done,” and that EAB “would kill every Ash tree in the country.” This media message was wrong and the effort to correct this message still exists.
Many challenges arose at the city level when EAB management was redirected to municipalities because of a lack of technical expertise, budget constraints, and scant research to guide decision makers. Today, volumes of conclusive data and strong field verification, some communities are still developing EAB plans based on inaccurate, outdated or wrong data. Some city leaders have still elected to remove and/or replace all healthy ash trees even when the science demonstrates that preserving trees is highly effective, far less costly, has a lower environmental impact, and keeping ash alive preserves the communities tree canopies.
The University Extension System
The university extension system was developed to disseminate scientific research from land grant institutions on a variety of agricultural concerns. The frequency, intensity, and enormity of the new pests that arborists face is unprecedented, and extension may not receive, and is not designed to respond with immediate solutions to these rapidly changing pest issues. Too often however, an extension agent, upon whom the public depends, receives information quite delayed from its release. Because pest-specific research is often accomplished by a handful of university scientists, that research is not always being released from their institutions to the stakeholders across the nation. The release of information is not well coordinated and new research can appear in a variety of trade journals.
Funding Issues
Funding for trees is often viewed by elected officials as a cost with little financial upside. The EAB expansion coincided with a severe downturn in the U.S. economy. With city leaders struggling to pay for basic community necessities, this tree-killing pest was not on their radar, nor in their budgets.
Tree planting feels good but saving trees is seldom viewed in the same positive light. This is especially disconcerting when science demonstrates that preserving mature trees offers the greatest long-term benefit to communities. Most city budgets are not designed to recognize tree protection as a “capital expense,” yet tree planting is considered an acceptable use of capital expense money.
Illinois has taken a leadership role in addressing the funding issue. Officials from the Illinois Municipal League support capitalization of tree treatment against invasive species because it is appropriate under present municipal financial guidelines and standards. The municipalities that classified invasive pest treatment costs as a capital expense provides significant flexibility in responding to the extraordinary and expensive municipal problem of EAB. The path to bonding for treatment is unobstructed in Illinois and this may be a favorable and fiscally sound direction for other states as well.
The Solution
Adding to the political complexity of researching invasive pests is the need to partner with for-profit companies who support research with new chemistry. In an effort to stay objective, university researchers often present solutions to a pest problem as alternatives, instead of ranking them by their performance against a given pest. It is not unusual for a university to be reluctant to consider scientific research conducted in another state, so the industry must conduct repetitive research on the same pests, with the same products, in the same tree species, while urban trees continue to die or are removed.
The responsible arborist leaves "unbiased" seminars lacking guidance on which product works best, on issues surrounding their use, and how can they make the best decisions for their constituents. University researchers and government agencies must consider and share solutions which best preserve canopy, offer cost effective results, and protect the environment, when presenting their research. Arborists should learn that the scientific evidence demonstrates that product "X" works in the most extreme infestations, while product "Y" works under light infestations, or that product "Z" has per acre use limitations, longer or shorter control windows, etc.
Any group capable of conducting an objective review needs to evaluate the extant information and provide the cities and arborists with facts, science, and the assorted considerations (environmental impact, cost, effectiveness, longevity, etc.). This is particularly needed for widespread invasive and non-invasive pests that cross state lines and devastate millions of trees. It should not depend on the depth of the pockets of a manufacturer as to whether this message spreads widely and quickly. Conclusions must be shared with all states, all agencies, and at all levels (including the public) to assure availability of accurate and current knowledge.
We must assure that small cities, with their limited budgets, limited resources, and limited knowledge do not manage this burden alone. Someone must speak for the trees to protect the public from bad, ill-informed generation-impacting decisions. We might consider cost sharing, natural disaster relief, and the development of bonding sources. In some states (Illinois is one) they have determined that treatment of trees can be capitalized whereas it was previously viewed as utilizing working capital. This means that treatment solutions increase value. In the past capitalization of new trees was the only way to get public money. This change in how bond money is disseminated should provide an alternative to panicked tree removals each time a serious pest attacks.
Multiple research groups have signed letters supporting treatment over removal. Citizens' protests and public polls support saving trees, yet millions have been lost for a lack of clear guidance, outdated information, or any understanding of the importance of our urban forests in keeping cities livable. If we are to learn from our mistakes in addressing tree killing pests, we must put systems into place to respond legislatively, fiscally, and scientifically to identify, quantify, and react decisively to protect our urban forests.
The Future
The study of present and future pests, while seeking solutions to minimize their impact on our forests, has been entrusted to a few universities and industry leaders. University extension creates a vital link by engaging in research and its dissemination. Research has not been made available readily or rapidly. The plant health care industry must also work with both federal and state agencies to quickly identify new threats, reach and share effective solutions, and then work to see them implemented, or we are destined to repeat the mistakes we have already made.
Tree removal can target a single-host pest or a small group of trees within a confined geographic region. However, it is unlikely that we can “cut” our way to solutions which offer effective results now and preserve the promise for the future. Given the right invasive species, lack of suitable pest predators, and challenging environmental conditions, we can expect one tree species after another to come under attack.
Summary
Tree removal strategies do not address the underlying causes of these outbreaks and represent an unsustainable arboricultural practice. Several tree canopy assessment tools exist which consider the value of tree canopy; including heating, cooling, storm water management, property value, and pollutant reduction, as well as the cost to treat or remove. With some new insecticide treatment products lasting two years, and researchers demonstrating more, it has become significantly less expensive to protect the urban forest than to incur the immediate cost of removal and replacement and the long-term changes that such removal brings to our communities.
We must continue to educate the public and legislators about the pest and its available controls. Of paramount importance is the implementing of changes to fiscal policy which will help communities to address the costs of invasive pests through contingency funds, bonding, public education, and outreach. To assure a successful response to invasive tree pests and diseases, we must demand better and more widely-disseminated education, and we must increase the sharing of research. We should neither fear the science nor its conclusions. Regardless of the message, a personal opinion should have little place in the preservation of our shared urban forests.
Sources
Rob Gorden is the Director of Urban Forestry for ArborJet
Our changing climate has allowed native and non-native pests to impact broader regions, to attack previously unaffected tree species, and to obtain highly destructive populations. Examples include the Mountain Pine Beetle, which has killed more trees than wildfires; Spruce Beetle; Gold Spotted Oak Borer; Sudden Oak Death; and HWA. Increasing moisture in the east has amplified the severity of leaf diseases, needle casts, and assorted blights. Droughts in the west weaken native trees, permitting explosive insect damage, as is now evident with significant new attacks by Western Pine Beetle in California.
Solutions
The scientific community studying these invasive pests shoulders the burden of identifying each pest and its life cycle; and then determining how to prevent them from destroying native and urban forests. The challenges include research-funding, as well as limitations and delay in recognizing that a new pest has arrived. Pests have a very specific annual life cycle which must be understood. Experimentation with suitable treatment options and methods require years to reach scientifically verifiable conclusions, while destruction continues unabated.
The USDA – APHIS (Animal and Plant Health Inspection Service) is the first line of defense to prevent invasives from spreading within the US. Their role is to eradicate these pests, not to manage them. If APHIS demonstrates success with containment and eradication, control remains with the agency. If the pest can not be eliminated, then management of the pest defers to local government, even if federal regulations and quarantines continue. The Asian Longhorned Beetle (ALB) program has been one of APHIS’s biggest successes. APHIS has treated 1.2 million trees against ALB and removed many infested trees, eradicating it in several state outbreaks.
The Emerald Ash Borer’s life cycle makes detection difficult, and APHIS could not stop its spread. Quarantines were imposed, but its ability to hide in firewood means we are still enhancing its spread. It has hitchhiked across two-thirds of the U.S. in just 18 years. Enormous resources are applied to set up, manage, and educate people on the “quarantine” for each new pest.
Far less money is directed towards educating citizens and professionals on practical solutions to preserve urban forests. The consequence has been enormous delays in the implementation of practical and timely solutions. This delay amplifies costs to local municipalities and private citizens seeking to preserve their urban forests.
Role of Government
State and local governments are designated to address wide reaching and devastating circumstances like floods, storms, and fires. However, naturally occurring invasive pest disasters are often beyond the scope of their expertise. When APHIS disconnected from the effort to eradicate EAB, the interpretation was “nothing can be done,” and that EAB “would kill every Ash tree in the country.” This media message was wrong and the effort to correct this message still exists.
Many challenges arose at the city level when EAB management was redirected to municipalities because of a lack of technical expertise, budget constraints, and scant research to guide decision makers. Today, volumes of conclusive data and strong field verification, some communities are still developing EAB plans based on inaccurate, outdated or wrong data. Some city leaders have still elected to remove and/or replace all healthy ash trees even when the science demonstrates that preserving trees is highly effective, far less costly, has a lower environmental impact, and keeping ash alive preserves the communities tree canopies.
The University Extension System
The university extension system was developed to disseminate scientific research from land grant institutions on a variety of agricultural concerns. The frequency, intensity, and enormity of the new pests that arborists face is unprecedented, and extension may not receive, and is not designed to respond with immediate solutions to these rapidly changing pest issues. Too often however, an extension agent, upon whom the public depends, receives information quite delayed from its release. Because pest-specific research is often accomplished by a handful of university scientists, that research is not always being released from their institutions to the stakeholders across the nation. The release of information is not well coordinated and new research can appear in a variety of trade journals.
Funding Issues
Funding for trees is often viewed by elected officials as a cost with little financial upside. The EAB expansion coincided with a severe downturn in the U.S. economy. With city leaders struggling to pay for basic community necessities, this tree-killing pest was not on their radar, nor in their budgets.
Tree planting feels good but saving trees is seldom viewed in the same positive light. This is especially disconcerting when science demonstrates that preserving mature trees offers the greatest long-term benefit to communities. Most city budgets are not designed to recognize tree protection as a “capital expense,” yet tree planting is considered an acceptable use of capital expense money.
Illinois has taken a leadership role in addressing the funding issue. Officials from the Illinois Municipal League support capitalization of tree treatment against invasive species because it is appropriate under present municipal financial guidelines and standards. The municipalities that classified invasive pest treatment costs as a capital expense provides significant flexibility in responding to the extraordinary and expensive municipal problem of EAB. The path to bonding for treatment is unobstructed in Illinois and this may be a favorable and fiscally sound direction for other states as well.
The Solution
Adding to the political complexity of researching invasive pests is the need to partner with for-profit companies who support research with new chemistry. In an effort to stay objective, university researchers often present solutions to a pest problem as alternatives, instead of ranking them by their performance against a given pest. It is not unusual for a university to be reluctant to consider scientific research conducted in another state, so the industry must conduct repetitive research on the same pests, with the same products, in the same tree species, while urban trees continue to die or are removed.
The responsible arborist leaves "unbiased" seminars lacking guidance on which product works best, on issues surrounding their use, and how can they make the best decisions for their constituents. University researchers and government agencies must consider and share solutions which best preserve canopy, offer cost effective results, and protect the environment, when presenting their research. Arborists should learn that the scientific evidence demonstrates that product "X" works in the most extreme infestations, while product "Y" works under light infestations, or that product "Z" has per acre use limitations, longer or shorter control windows, etc.
Any group capable of conducting an objective review needs to evaluate the extant information and provide the cities and arborists with facts, science, and the assorted considerations (environmental impact, cost, effectiveness, longevity, etc.). This is particularly needed for widespread invasive and non-invasive pests that cross state lines and devastate millions of trees. It should not depend on the depth of the pockets of a manufacturer as to whether this message spreads widely and quickly. Conclusions must be shared with all states, all agencies, and at all levels (including the public) to assure availability of accurate and current knowledge.
We must assure that small cities, with their limited budgets, limited resources, and limited knowledge do not manage this burden alone. Someone must speak for the trees to protect the public from bad, ill-informed generation-impacting decisions. We might consider cost sharing, natural disaster relief, and the development of bonding sources. In some states (Illinois is one) they have determined that treatment of trees can be capitalized whereas it was previously viewed as utilizing working capital. This means that treatment solutions increase value. In the past capitalization of new trees was the only way to get public money. This change in how bond money is disseminated should provide an alternative to panicked tree removals each time a serious pest attacks.
Multiple research groups have signed letters supporting treatment over removal. Citizens' protests and public polls support saving trees, yet millions have been lost for a lack of clear guidance, outdated information, or any understanding of the importance of our urban forests in keeping cities livable. If we are to learn from our mistakes in addressing tree killing pests, we must put systems into place to respond legislatively, fiscally, and scientifically to identify, quantify, and react decisively to protect our urban forests.
The Future
The study of present and future pests, while seeking solutions to minimize their impact on our forests, has been entrusted to a few universities and industry leaders. University extension creates a vital link by engaging in research and its dissemination. Research has not been made available readily or rapidly. The plant health care industry must also work with both federal and state agencies to quickly identify new threats, reach and share effective solutions, and then work to see them implemented, or we are destined to repeat the mistakes we have already made.
Tree removal can target a single-host pest or a small group of trees within a confined geographic region. However, it is unlikely that we can “cut” our way to solutions which offer effective results now and preserve the promise for the future. Given the right invasive species, lack of suitable pest predators, and challenging environmental conditions, we can expect one tree species after another to come under attack.
Summary
Tree removal strategies do not address the underlying causes of these outbreaks and represent an unsustainable arboricultural practice. Several tree canopy assessment tools exist which consider the value of tree canopy; including heating, cooling, storm water management, property value, and pollutant reduction, as well as the cost to treat or remove. With some new insecticide treatment products lasting two years, and researchers demonstrating more, it has become significantly less expensive to protect the urban forest than to incur the immediate cost of removal and replacement and the long-term changes that such removal brings to our communities.
We must continue to educate the public and legislators about the pest and its available controls. Of paramount importance is the implementing of changes to fiscal policy which will help communities to address the costs of invasive pests through contingency funds, bonding, public education, and outreach. To assure a successful response to invasive tree pests and diseases, we must demand better and more widely-disseminated education, and we must increase the sharing of research. We should neither fear the science nor its conclusions. Regardless of the message, a personal opinion should have little place in the preservation of our shared urban forests.
Sources
- Siegert, Nathan W., D. G. McCullough & F.W. Telewski. 2014. "Dendrochronological reconstruction of the epicenter and early spread of emerald ash borer in North America. "Diversity and Distributions.
- Van Natta, A.R., N. M. Schuettpelz, and R.H. Hauer, "Cost Analysis of Removal and Replacement vs. Treatment of Ash Trees Susceptible to Emerald Ash Borer on the UW-Stevens Point Campus." Proceedings of the International Society of Arboriculture, 2010.
Rob Gorden is the Director of Urban Forestry for ArborJet
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the .5 CEUs toward Certified Arborist, or BCMA science credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to gibneyCE.com’. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website. *SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the .5 CEUs toward Certified Arborist, or BCMA science credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to gibneyCE.com’. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website. *SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
History of Utility Arboriculture
Edited by Len Phillips
There has been a conflict between trees and utility lines since the first telegraph wires were installed between Washington, DC and Baltimore, Maryland in 1839. When the telephone was invented in 1875, and electric lines were installed starting in 1882, more tree and utility line conflicts developed. A number of laws were passed in the1880’s that allowed the utility companies to control tree trimming around all the wires. Permits were required to prune, plant, and remove trees on and beside the utility easements. The point then, as now, was that the reliable delivery of power and communication is very important.
It was not until World War II that things began to change. At that time, several factors came into play.
Edited by Len Phillips
There has been a conflict between trees and utility lines since the first telegraph wires were installed between Washington, DC and Baltimore, Maryland in 1839. When the telephone was invented in 1875, and electric lines were installed starting in 1882, more tree and utility line conflicts developed. A number of laws were passed in the1880’s that allowed the utility companies to control tree trimming around all the wires. Permits were required to prune, plant, and remove trees on and beside the utility easements. The point then, as now, was that the reliable delivery of power and communication is very important.
It was not until World War II that things began to change. At that time, several factors came into play.
- The geographical size of transmission
rights-of-way (those carrying utility service over long distances) had grown
along with the population and its demand for electrical service.
- The war had drained the labor
pool.
- A book titled "Overhead Line
Clearance" by E.D. Blair (published in 1940) opened the door to the
professional management of utility rights-of-way. This book is still current despite the fact
that the information was written 75 years ago.
The book was published and is still used as a textbook for forestry
students.
Line Clearance
For the first half of the twentieth century, trimming around electric power lines was as excessive as it was around the telephone lines which were not insulated until the 1950’s. Right-of-way clearance and maintenance was labor intensive and done manually with brush hooks (a type of heavy ax) and crosscut saws. Brush had to be loaded onto trucks and hauled to a dump site. During and soon after the War in the 1940’s, a practice began to have massive piles of brush burned near the clearing site to dispose of the removed trees and branches. Burning was less expensive than hauling the material away. However it was also environmentally insensitive and not without danger. Utility companies saw the need for a better method because not only did right-of-way maintenance have an impact on reliability, but it was also having an impact on the profits of the investor-owned utilities. Blair's book began the shift in thinking from right-of-way clearance as a maintenance task, to that of a managed maintenance program.
Proper pruning was first written in lineman’s manuals in the 1940’s as a main goal for a managed maintenance program. These manuals discussed proper cuts and proper tree care. Since all the cutting was done with hand saws, the shortest cut on a branch was recommended. This was and still is the proper way.
Equipment
When the chain saw was developed in the 1940’s, they were quite large and useful for dropping the tree. Flush cuts became popular for for ease of cutting limbs, even though it was not good for the tree. It wasn’t until the 1960’s that the saws became light enough to use up in the tree. The lighter saws prompted the guidelines to cease recommending flush cuts because they were so damaging to the trees.
An all steel aerial lift was also developed in the 1940’s. The insulated aerial lift was developed by Asplundh in 1954. There were no brush chippers until Asplundh invented one in 1950. Pruners and hand saws have not changed much in the past 125 years. In the 1950s, former military vehicles capable of traveling the rough terrain found on transmission rights-of-way began to appear, giving a much-needed rest to the horses and mules that the crews had been using since the beginning of transmission line clearance. Surplus vehicles from World War II such as jeeps, trucks, and retired military tanks, were adapted for right-of-way clearance. Surplus aircraft tires were even put to use to give buoyancy to vehicles working in rough or wet terrain along the right-of-way. There was no concern for the environment, compacted soil, or proper tree care until the 1970’s.
Herbicides became necessary during and right after World War II because of the major labor shortage. Early herbicides from 1910 to 1930 were very potent and were reported to have killed cattle that ate grass that were covered with spray drift. In the 1950’s, the chemical manufacturing industry developed herbicides that showed more specific plant toxicity and more environmental safety.
Today
Everyone now knows how important trees are to people and the utilities have changed their view of trees as a problem for reliable service. Today the utilities are concerned about public safety and safe trees. Despite the apparent conflict, utilities do want to do what is right for the trees when pruning and planting. Often a utility must remove a tree that is too close to the power lines, so the companies are replacing trees where they will not conflict with the lines. The new plantings include low growing trees under the lines and planting tall trees on the other side of the street in residential neighborhoods. Some utilities are also providing training sessions for arborists in proper and safe public tree trimming.
Today utility arborist students and those people entering the field must be ISA certified and many utility companies participate in the Tree Line USA, sponsored by the National Arbor Day Foundation, the originators of Tree City USA.
UAA
The Utility Arborists Association (UAA) was established in 1974 with the primary function of providing an association where utility arborists employed by electric utilities could network and share information. The UAA mission was to be the leading North American organization for the enhancement of quality utility arboriculture and right-of-way vegetation management. The membership grew to approximately 500 by 1992. In this same year, the UAA secured the services of an executive director and editor to manage the membership, represent the UAA, and edit a newsletter. Through various initiatives, membership has grown to nearly 3,000 members at the present time.
The UAA conducts several events to provide utility arborists with the latest information and trends in their industry. One event is the System Utility Vegetation Management Summit where members discuss best practices based on recent research papers. These papers have not undergone the type of rigorous review that would qualify them as “Best Management Practices” but they reflect the discussions and suggestions among industry leaders. Recently, the Tree Care Industry Association began offering accreditation to companies who wish to contract with certain utilities or municipalities requiring the credential.
Sources
For the first half of the twentieth century, trimming around electric power lines was as excessive as it was around the telephone lines which were not insulated until the 1950’s. Right-of-way clearance and maintenance was labor intensive and done manually with brush hooks (a type of heavy ax) and crosscut saws. Brush had to be loaded onto trucks and hauled to a dump site. During and soon after the War in the 1940’s, a practice began to have massive piles of brush burned near the clearing site to dispose of the removed trees and branches. Burning was less expensive than hauling the material away. However it was also environmentally insensitive and not without danger. Utility companies saw the need for a better method because not only did right-of-way maintenance have an impact on reliability, but it was also having an impact on the profits of the investor-owned utilities. Blair's book began the shift in thinking from right-of-way clearance as a maintenance task, to that of a managed maintenance program.
Proper pruning was first written in lineman’s manuals in the 1940’s as a main goal for a managed maintenance program. These manuals discussed proper cuts and proper tree care. Since all the cutting was done with hand saws, the shortest cut on a branch was recommended. This was and still is the proper way.
Equipment
When the chain saw was developed in the 1940’s, they were quite large and useful for dropping the tree. Flush cuts became popular for for ease of cutting limbs, even though it was not good for the tree. It wasn’t until the 1960’s that the saws became light enough to use up in the tree. The lighter saws prompted the guidelines to cease recommending flush cuts because they were so damaging to the trees.
An all steel aerial lift was also developed in the 1940’s. The insulated aerial lift was developed by Asplundh in 1954. There were no brush chippers until Asplundh invented one in 1950. Pruners and hand saws have not changed much in the past 125 years. In the 1950s, former military vehicles capable of traveling the rough terrain found on transmission rights-of-way began to appear, giving a much-needed rest to the horses and mules that the crews had been using since the beginning of transmission line clearance. Surplus vehicles from World War II such as jeeps, trucks, and retired military tanks, were adapted for right-of-way clearance. Surplus aircraft tires were even put to use to give buoyancy to vehicles working in rough or wet terrain along the right-of-way. There was no concern for the environment, compacted soil, or proper tree care until the 1970’s.
Herbicides became necessary during and right after World War II because of the major labor shortage. Early herbicides from 1910 to 1930 were very potent and were reported to have killed cattle that ate grass that were covered with spray drift. In the 1950’s, the chemical manufacturing industry developed herbicides that showed more specific plant toxicity and more environmental safety.
Today
Everyone now knows how important trees are to people and the utilities have changed their view of trees as a problem for reliable service. Today the utilities are concerned about public safety and safe trees. Despite the apparent conflict, utilities do want to do what is right for the trees when pruning and planting. Often a utility must remove a tree that is too close to the power lines, so the companies are replacing trees where they will not conflict with the lines. The new plantings include low growing trees under the lines and planting tall trees on the other side of the street in residential neighborhoods. Some utilities are also providing training sessions for arborists in proper and safe public tree trimming.
Today utility arborist students and those people entering the field must be ISA certified and many utility companies participate in the Tree Line USA, sponsored by the National Arbor Day Foundation, the originators of Tree City USA.
UAA
The Utility Arborists Association (UAA) was established in 1974 with the primary function of providing an association where utility arborists employed by electric utilities could network and share information. The UAA mission was to be the leading North American organization for the enhancement of quality utility arboriculture and right-of-way vegetation management. The membership grew to approximately 500 by 1992. In this same year, the UAA secured the services of an executive director and editor to manage the membership, represent the UAA, and edit a newsletter. Through various initiatives, membership has grown to nearly 3,000 members at the present time.
The UAA conducts several events to provide utility arborists with the latest information and trends in their industry. One event is the System Utility Vegetation Management Summit where members discuss best practices based on recent research papers. These papers have not undergone the type of rigorous review that would qualify them as “Best Management Practices” but they reflect the discussions and suggestions among industry leaders. Recently, the Tree Care Industry Association began offering accreditation to companies who wish to contract with certain utilities or municipalities requiring the credential.
Sources
- Odom, F. Perry, “Less is More: Utility Line Clearance in Tallahassee Florida”, City of Tallahassee Electric, 2009.
- Orr, Jim, “History of Utility Arboriculture”, City Trees, July/August 1998.
- Orr, Jim and Dan Kinter, “Right-of-way Management”, Arbor Age, July, 2003.
- Utility Arborists Association, website, 2015.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the .5 CEUs toward Certified Arborist, Utility Specialist, or BCMA management credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to gibneyCE.com’. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website. *SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the .5 CEUs toward Certified Arborist, Utility Specialist, or BCMA management credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to gibneyCE.com’. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website. *SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Biochar Update
Edited by Len Phillips
Biochar is a carbon-rich soil enhancement that is a type of charcoal made from plant waste. It’s a natural material that makes agricultural land more fertile and shows great promise for city trees and shrubs. It helps retain soil moisture thereby reducing the need for watering. It persists in the soil for years, reducing or eliminating the need for re-application. It even has the potential to help offset climate change since it holds carbon in the soil indefinitely, preventing it from escaping into the atmosphere and contributing to the greenhouse effect.
Recently, researchers began conducting the first studies investigating biochar’s impact on improving the interactions of roots and soils in the compacted soil typical of urban and suburban areas. The research indicates that biochar can have a measurable positive impact on soil quality and plant growth.
Biochar and Compost
Biochar works best in combination with compost. While applying biochar alone is beneficial in the long term, applying it in combination with compost yields the best short-term results. Biochar itself does not provide nutrition or moisture, but it has an ability to adsorb other substances. When biochar is mixed with organic matter like compost, the biochar fills up with nutrients and water. It is then made available to plants at a later time, when needed.
Biochar will actually draw nutrients and water out of the soil at first, which could mean negative short-term results for plants. But once the biochar is wet, the microbes and moisture flow in and out of it and it becomes part of the soil continuum.
Biochar and Fertilizer
While fertilizer can also be a nutrient source to charge biochar for short-term results, the organic matter of compost provides the microbial activity and nutrient cycling that fertilizer does not. Fertilizer does not recreate a forest soil, like compost can. But it still plays an important role in soil management. For instance, adding fertilizer along with compost and biochar will improve soil conditions and structure.
Edited by Len Phillips
Biochar is a carbon-rich soil enhancement that is a type of charcoal made from plant waste. It’s a natural material that makes agricultural land more fertile and shows great promise for city trees and shrubs. It helps retain soil moisture thereby reducing the need for watering. It persists in the soil for years, reducing or eliminating the need for re-application. It even has the potential to help offset climate change since it holds carbon in the soil indefinitely, preventing it from escaping into the atmosphere and contributing to the greenhouse effect.
Recently, researchers began conducting the first studies investigating biochar’s impact on improving the interactions of roots and soils in the compacted soil typical of urban and suburban areas. The research indicates that biochar can have a measurable positive impact on soil quality and plant growth.
Biochar and Compost
Biochar works best in combination with compost. While applying biochar alone is beneficial in the long term, applying it in combination with compost yields the best short-term results. Biochar itself does not provide nutrition or moisture, but it has an ability to adsorb other substances. When biochar is mixed with organic matter like compost, the biochar fills up with nutrients and water. It is then made available to plants at a later time, when needed.
Biochar will actually draw nutrients and water out of the soil at first, which could mean negative short-term results for plants. But once the biochar is wet, the microbes and moisture flow in and out of it and it becomes part of the soil continuum.
Biochar and Fertilizer
While fertilizer can also be a nutrient source to charge biochar for short-term results, the organic matter of compost provides the microbial activity and nutrient cycling that fertilizer does not. Fertilizer does not recreate a forest soil, like compost can. But it still plays an important role in soil management. For instance, adding fertilizer along with compost and biochar will improve soil conditions and structure.
- A
synergy exists between compost and biochar.
Not only does combining compost with biochar improve biochar’s
performance, blending the two also makes compost more effective. When biochar and compost are combined, trees
and shrubs show greater growth and performance than with either of the two
amendments alone.
- More
is not necessarily better. Often with soil amendments, if
one lump is good, two lumps are better. It is especially true with
compost. However, this does not apply to
biochar. The research shows that a
little bit goes a long way, which certainly has an added cost benefit.
- Moisture
retention in soils with biochar had higher levels of soil moisture throughout
the growing season than those without biochar.
- Disease
resistance in seedlings growing in soil with biochar have
significantly improved resistance to phytophthora canker. While the results are promising,
it
is too early to tell if similar results will occur with landscape trees and
other diseases.
- Increased
root and plant growth was found in tree seedlings planted in soil that had
biochar top-dressing compared to seedlings growing in soil treated simply with
water.
Sustainability
Investigations of using biochar was compared to other planting soil treatments of the material itself, labor, transportation, equipment and other costs, along with costs to water, mulch, add compost, fertilizer, aerated compost tea, commercial biological products, biochar, and biosolids. This effort was then compared to increases in plant growth. From lowest to highest costs, biochar ranked fifth among the eight treatments. Biosolids and mulch were the least expensive, while aerated compost tea and commercial biological products were the most expensive. While compost can provide more organic matter in the short term, biochar can potentially improve soil quality for a longer period.
This investigation did not consider the money saved and the environmental benefits of diverting the plant waste that is used to make biochar instead of being dumped in landfills, as well as the climate benefits of long-term carbon storage.
Looking Ahead
One big question looking ahead is whether biochar could be a component of structural soils or a tree pit soil mix. With tree pits, the idea is to grow big trees in small spaces. However, with a soil volume that’s entombed by concrete and compacted soil, not only is there limited room for roots to grow, but there is no potential for nutrient recycling from leaves dropping in the fall.
The researchers have amended the soil of some of the trees with biochar, others with biochar plus fertilizer, and still others with fertilizer alone to see if they can improve the conditions in this stressful growing environment. The hope is that biochar could help give urban street trees a lifespan of more than the typical period of less than 20 years.
Biochar Cautions
Researchers are still somewhat cautious about the use of biochar in tree plantings. The physical, biological, and chemical processes that biochar may exert on microbial communities and tree roots are not yet fully understood. The currently available data on the effect of biochar on soil gas is very limited.
Sources
Investigations of using biochar was compared to other planting soil treatments of the material itself, labor, transportation, equipment and other costs, along with costs to water, mulch, add compost, fertilizer, aerated compost tea, commercial biological products, biochar, and biosolids. This effort was then compared to increases in plant growth. From lowest to highest costs, biochar ranked fifth among the eight treatments. Biosolids and mulch were the least expensive, while aerated compost tea and commercial biological products were the most expensive. While compost can provide more organic matter in the short term, biochar can potentially improve soil quality for a longer period.
This investigation did not consider the money saved and the environmental benefits of diverting the plant waste that is used to make biochar instead of being dumped in landfills, as well as the climate benefits of long-term carbon storage.
Looking Ahead
One big question looking ahead is whether biochar could be a component of structural soils or a tree pit soil mix. With tree pits, the idea is to grow big trees in small spaces. However, with a soil volume that’s entombed by concrete and compacted soil, not only is there limited room for roots to grow, but there is no potential for nutrient recycling from leaves dropping in the fall.
The researchers have amended the soil of some of the trees with biochar, others with biochar plus fertilizer, and still others with fertilizer alone to see if they can improve the conditions in this stressful growing environment. The hope is that biochar could help give urban street trees a lifespan of more than the typical period of less than 20 years.
Biochar Cautions
Researchers are still somewhat cautious about the use of biochar in tree plantings. The physical, biological, and chemical processes that biochar may exert on microbial communities and tree roots are not yet fully understood. The currently available data on the effect of biochar on soil gas is very limited.
Sources
- Jamieson,
Scott, “Delving
into Biochar”, The
Landscape Contractor, March 2013.
- “News
around Biochar”, International Biochar Initiative, 2015.
*Members of ISA may apply the .5 CEUs toward Certified
Arborist, or BCMA science credits.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the .5 CEUs toward Certified Arborist, or BCMA science credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to gibneyCE.com’. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website. *SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the .5 CEUs toward Certified Arborist, or BCMA science credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to gibneyCE.com’. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website. *SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Cultivars of the Shantung Maple
Edited by Len Phillips
Shantung Maple is a favorite that does well in residential areas of Midwestern cities. Acer truncatum is known as the Shantung maple, Shandong maple, or Purpleblow maple. This Asian species is quite at home across a broad range of harsh habitats. The description that follows provides a summary of similarities that all the cultivars possess. This information has been gathered from personal observations by the author, living in Massachusetts, Zone 6, and information provided by J. Frank Schmidt & Son.
Common Name: Shantung Maple
Botanical Name: Acer truncatum x platanoides
Hardiness Zone: 4 – 8
Bloom Period: May Flower: Greenish yellow, insignificant with one exception noted below
Fruit: Samara, greenish ripening to light brown
Foliage: Glossy, 5 lobes, 3 – 5 inches wide, color varies with cultivar
Winter Interest: Bark provides winter interest
Bark: Purple tinged when young, gray brown with age. As a tree ages, the bark transitions smooth to vertical ridges
Growth Rate: Moderate, average growth of 1 ft. a year, 35' tall in 30 years
Planting: Easy to transplant bare root, B&B, container, and tree spade. Very suitable for CU-Structural Soil planting
Propagating: Stem cuttings, budded, or grafted
Site Requirements: Excellent heat, alkaline, and drought tolerance, grows in most soils tolerates extreme heat and full sun of the Great Plains and global warming.
Pest Problems: None, most are resistant to Japanese Beetle
Salt Tolerance: Fair
Design Uses: Specimen for lawns, parks, streets, and residential locations
Companions: Use with evergreen shrubs planted the year after planting the tree
Other Comments: Excellent tree for city streets, similar to Norway Maple in shape, growth rate, branch structure, and leaf shape. The heat tolerance of this tree will make it very important in the future with global warming.
“Sunset” is a series of Acer truncatum x A. plantanoides maples introduced by J. Frank Schmidt & Son.
Crimson Sunset® Maple – Acer truncatum x A. platanoides ‘JFS-KW202’ – PP #21838 – Height: 35’; spread: 25’; Shape: upright oval; Foliage: deep purple; Fall Color: maroon to reddish bronze. Heat tolerance is
the distinguishing characteristic of this Acer truncatum hybrid. Its foliage resembles that of Crimson King, but its form is more compact. Thanks to the Acer truncatum parentage, it flourishes in the summer heat where few purple leafed trees can survive. Fact Sheet
Norwegian Sunset® Maple – Acer truncatum x Acer platanoides ‘Keithsform’ – Height: 35'; Spread: 25'; Shape: oval; Foliage: dark green, glossy; Fall Color: yellow-orange to red. An upright oval tree with brilliant fall color, Norwegian Sunset® has a particularly nice branch structure and uniform canopy. It's Acer truncatum parentage gives this tree glossy foliage and heat resistance. Fact Sheet
Pacific Sunset® Maple – Acer truncatum x Acer platanoides ‘Warrenred’ – Height: 30'; Spread: 25'; Shape: upright spreading, rounded crown; Foliage: dark green, smooth, very glossy; Fall Color: yellow-orange to bright red. Outstanding glossy summer foliage changes to tints of yellow, red, and orange in the fall. Pacific Sunset® colors earlier and a little brighter than Norwegian Sunset.®. Branch structure is a little finer textured and more spreading than Norwegian Sunset.®. Fact Sheet
Ruby Sunset™ Maple – Acer truncatum × A. platanoides ‘JFS-KW249’ – Height: 25'; Spread: 20'; Shape: broadly oval to rounded; Foliage: dark green, glossy; Fall Color: deep red. Elegant foliage stays fresh and glossy throughout the growing season. Hybrid origin adds cold hardiness and adaptability to this selection that most resembles A. truncatum in appearance, growth habit and size. A great choice for smaller sites requiring a more compact tree. Fact Sheet
Urban Sunset™ Maple – Acer truncatum × platanoides ‘JFS-KW187’ – Height: 35’; Spread: 20’; Shape: narrow pyramidal ; Foliage: dark green, glossy; Fall Color: deep red. Compact, upright and narrow, this tree develops a naturally uniform canopy with minimal pruning. It is easy to grow and relatively problem free and it produces few seeds. Urban Sunset develops an ideal, upright street tree form. Fact Sheet
Fire Dragon® Shantung Maple – Acer truncatum 'Fire Dragon®' – PP #17367 was discovered and introduced by Metro Maples of Fort Worth, Texas. Height: 35’; Spread: 35’; Shape: rounded crown; Foliage: near perfect leaf shape that makes a more elegant and cleaner looking tree. New leaf growth is a burnt orange, changing to a dark glossy green. Fall color is a brilliant scarlet color. Fire Dragon is the most consistent and reddest Shantung maple. Hardy and heat tolerant, it will grow just about anywhere in acidic or alkaline soils. Fire Dragon has clusters of bright yellow flowers that appear before the foliage in spring. Fact Sheet
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the .5 CEUs toward Certified Arborist, or BCMA science credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to gibneyCE.com’. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website. *SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Edited by Len Phillips
Shantung Maple is a favorite that does well in residential areas of Midwestern cities. Acer truncatum is known as the Shantung maple, Shandong maple, or Purpleblow maple. This Asian species is quite at home across a broad range of harsh habitats. The description that follows provides a summary of similarities that all the cultivars possess. This information has been gathered from personal observations by the author, living in Massachusetts, Zone 6, and information provided by J. Frank Schmidt & Son.
Common Name: Shantung Maple
Botanical Name: Acer truncatum x platanoides
Hardiness Zone: 4 – 8
Bloom Period: May Flower: Greenish yellow, insignificant with one exception noted below
Fruit: Samara, greenish ripening to light brown
Foliage: Glossy, 5 lobes, 3 – 5 inches wide, color varies with cultivar
Winter Interest: Bark provides winter interest
Bark: Purple tinged when young, gray brown with age. As a tree ages, the bark transitions smooth to vertical ridges
Growth Rate: Moderate, average growth of 1 ft. a year, 35' tall in 30 years
Planting: Easy to transplant bare root, B&B, container, and tree spade. Very suitable for CU-Structural Soil planting
Propagating: Stem cuttings, budded, or grafted
Site Requirements: Excellent heat, alkaline, and drought tolerance, grows in most soils tolerates extreme heat and full sun of the Great Plains and global warming.
Pest Problems: None, most are resistant to Japanese Beetle
Salt Tolerance: Fair
Design Uses: Specimen for lawns, parks, streets, and residential locations
Companions: Use with evergreen shrubs planted the year after planting the tree
Other Comments: Excellent tree for city streets, similar to Norway Maple in shape, growth rate, branch structure, and leaf shape. The heat tolerance of this tree will make it very important in the future with global warming.
“Sunset” is a series of Acer truncatum x A. plantanoides maples introduced by J. Frank Schmidt & Son.
Crimson Sunset® Maple – Acer truncatum x A. platanoides ‘JFS-KW202’ – PP #21838 – Height: 35’; spread: 25’; Shape: upright oval; Foliage: deep purple; Fall Color: maroon to reddish bronze. Heat tolerance is
the distinguishing characteristic of this Acer truncatum hybrid. Its foliage resembles that of Crimson King, but its form is more compact. Thanks to the Acer truncatum parentage, it flourishes in the summer heat where few purple leafed trees can survive. Fact Sheet
Norwegian Sunset® Maple – Acer truncatum x Acer platanoides ‘Keithsform’ – Height: 35'; Spread: 25'; Shape: oval; Foliage: dark green, glossy; Fall Color: yellow-orange to red. An upright oval tree with brilliant fall color, Norwegian Sunset® has a particularly nice branch structure and uniform canopy. It's Acer truncatum parentage gives this tree glossy foliage and heat resistance. Fact Sheet
Pacific Sunset® Maple – Acer truncatum x Acer platanoides ‘Warrenred’ – Height: 30'; Spread: 25'; Shape: upright spreading, rounded crown; Foliage: dark green, smooth, very glossy; Fall Color: yellow-orange to bright red. Outstanding glossy summer foliage changes to tints of yellow, red, and orange in the fall. Pacific Sunset® colors earlier and a little brighter than Norwegian Sunset.®. Branch structure is a little finer textured and more spreading than Norwegian Sunset.®. Fact Sheet
Ruby Sunset™ Maple – Acer truncatum × A. platanoides ‘JFS-KW249’ – Height: 25'; Spread: 20'; Shape: broadly oval to rounded; Foliage: dark green, glossy; Fall Color: deep red. Elegant foliage stays fresh and glossy throughout the growing season. Hybrid origin adds cold hardiness and adaptability to this selection that most resembles A. truncatum in appearance, growth habit and size. A great choice for smaller sites requiring a more compact tree. Fact Sheet
Urban Sunset™ Maple – Acer truncatum × platanoides ‘JFS-KW187’ – Height: 35’; Spread: 20’; Shape: narrow pyramidal ; Foliage: dark green, glossy; Fall Color: deep red. Compact, upright and narrow, this tree develops a naturally uniform canopy with minimal pruning. It is easy to grow and relatively problem free and it produces few seeds. Urban Sunset develops an ideal, upright street tree form. Fact Sheet
Fire Dragon® Shantung Maple – Acer truncatum 'Fire Dragon®' – PP #17367 was discovered and introduced by Metro Maples of Fort Worth, Texas. Height: 35’; Spread: 35’; Shape: rounded crown; Foliage: near perfect leaf shape that makes a more elegant and cleaner looking tree. New leaf growth is a burnt orange, changing to a dark glossy green. Fall color is a brilliant scarlet color. Fire Dragon is the most consistent and reddest Shantung maple. Hardy and heat tolerant, it will grow just about anywhere in acidic or alkaline soils. Fire Dragon has clusters of bright yellow flowers that appear before the foliage in spring. Fact Sheet
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the .5 CEUs toward Certified Arborist, or BCMA science credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to gibneyCE.com’. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website. *SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
Utility Lines versus Shade Trees – Part 2
Edited by Len Phillips
As mentioned in Seminar #62, municipal arborists have a major disdain for overhead utility lines that are interfering with large tree branches. The previous article discussed the use of trenchless technology to install all new and replacement utility lines underground. Since that time, Online Seminars and its Urban Forestry discussion group on LinkedIn, have come up with several other alternatives to improving utility reliability while protecting and preserving the urban forest. These ideas include:
Edited by Len Phillips
As mentioned in Seminar #62, municipal arborists have a major disdain for overhead utility lines that are interfering with large tree branches. The previous article discussed the use of trenchless technology to install all new and replacement utility lines underground. Since that time, Online Seminars and its Urban Forestry discussion group on LinkedIn, have come up with several other alternatives to improving utility reliability while protecting and preserving the urban forest. These ideas include:
- Each utility company should have a
committee of citizens and arborists who decide how the electric utility would
proceed with its line clearance tree trimming operations, clearance
requirements, tree removals and replacements, etc.
- Most utility companies should continue
to take advantage of tree care equipment improvements being developed and put
on the market.
- The utility should require the
contractor to provide pre-inspectors or supervisors who would notify and obtain
permissions to trim the customers’ trees in advance of the trimming crews
arriving on the site.
- The utility companies should establish
a scheduled tree trimming cycle.
- The utilities should require the
contractors to prune to the necessary clearance while maintaining pruning
standards based on ANSI A-300.
- Each utility should recommend that all
line clearance contracts go to a contractor based on the number of line miles
that are trimmed instead of an hourly rate for labor and equipment. This change will result in a significant cost
savings to the utility.
- Each utility should create “Super
Crews” that consist of two to four bucket trucks leap-frogging on a line, with
one follow-up chipping crew. This allows
the bucket crews to trim continuously without having to stop and chip their
brush.
- The utilities should use tree wire or
cables, sometimes referred to as Hendrix aerial spacer
cable systems that group the three-phase primary
wires in a much tighter configuration on the pole. This results in
significantly improved reliability rates and a
reduced trimming clearance requirement.
In addition, there have been many occasions where limbs and even whole
trees have fallen onto the tree wire and not caused an outage because they were
held up with the cable.
- The utilities should try to design new
lines to zig-zag back and forth across the road leaving most of the conductors
out over the middle of the road. This
technique requires pruning only the trees closest to the poles where the lines
are attached.
- Each utility should establish a tree
replacement policy that prohibits the planting of large trees under the
existing power lines and replaces trees removed to ensure reliability, with low
growing trees that will not need their tops trimmed.
- Each utility should develop a plan to
use Tree Growth Regulators (TGRs) on “significant trees”. This practice will greatly reduce the
trimming requirements by slowing the significant tree’s growth. The TGR crew should be specialized in
treating these significant trees.
UAA
The Utility Arborists Association is now promoting a “Less is More” program which means pruning “Less” to create “More” aesthetically pleasing trees along the roadways. This “Less” pruning plan means “More” cooperation from homeowner associations and individuals when there is a need to construct or relocate lines for road widening projects or system upgrades. “Less” pruning means “More” reliability because of the reduction of re-growth after the pruning operation. But most importantly “Less” pruning means “More” happy customers.
The UAA is encouraging many utilities to phase out their overhead lines and place them underground during their scheduled line replacement programs. These utilities have invested in horizontal direction drilling equipment as mentioned in Seminar #62 which allows them to efficiently steer a plastic conduit pipe underground to avoid other underground utilities. The insulated cables are pulled into the conduit. The cost savings is significant during storms and the reliability is greatly improved.
Most of the utility companies had been promoting the use of conservation practices to cut back on the amount of electricity consumed by the average household in an effort to reduce the need for additional, expensive, power generation facilities that would raise power costs substantially. However, this effort has started to backfire on the utility, as consumers are reducing power needs beyond what was expected and in many cases the consumers have installed solar and wind generators in their homes and are selling surplus power back to the utilities. Now the utilities have to deal with cutbacks in their operation costs because their income has been greatly reduced. The only hope for utility survival is if they can transmit power from the points of generation to the consumer by any means except high maintenance electric wires.
The UAA predicts that the utility industry will have an unpredictable future. The utility companies are merging, cutting costs, and changing maintenance priorities. Nothing is certain and nothing can be predicted for the future. Since telephone and cable services are becoming wireless, it may be only a matter of time before electric service no longer needs wires. (As arborists, we can only hope.)
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the .5 CEUs toward Certified Arborist, Utility Specialist, or BCMA management credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to gibneyCE.com’. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website. *SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.
The Utility Arborists Association is now promoting a “Less is More” program which means pruning “Less” to create “More” aesthetically pleasing trees along the roadways. This “Less” pruning plan means “More” cooperation from homeowner associations and individuals when there is a need to construct or relocate lines for road widening projects or system upgrades. “Less” pruning means “More” reliability because of the reduction of re-growth after the pruning operation. But most importantly “Less” pruning means “More” happy customers.
The UAA is encouraging many utilities to phase out their overhead lines and place them underground during their scheduled line replacement programs. These utilities have invested in horizontal direction drilling equipment as mentioned in Seminar #62 which allows them to efficiently steer a plastic conduit pipe underground to avoid other underground utilities. The insulated cables are pulled into the conduit. The cost savings is significant during storms and the reliability is greatly improved.
Most of the utility companies had been promoting the use of conservation practices to cut back on the amount of electricity consumed by the average household in an effort to reduce the need for additional, expensive, power generation facilities that would raise power costs substantially. However, this effort has started to backfire on the utility, as consumers are reducing power needs beyond what was expected and in many cases the consumers have installed solar and wind generators in their homes and are selling surplus power back to the utilities. Now the utilities have to deal with cutbacks in their operation costs because their income has been greatly reduced. The only hope for utility survival is if they can transmit power from the points of generation to the consumer by any means except high maintenance electric wires.
The UAA predicts that the utility industry will have an unpredictable future. The utility companies are merging, cutting costs, and changing maintenance priorities. Nothing is certain and nothing can be predicted for the future. Since telephone and cable services are becoming wireless, it may be only a matter of time before electric service no longer needs wires. (As arborists, we can only hope.)
The test that follows contains 10 questions. Before taking the test be sure you have read the article carefully. The passing grade is 80% on the entire test.
ISA will award .5 CEUs* for a passing grade. SAF members will earn 0.5 Cat. 1-CF for every five passing test scores. The cost for taking this test is $10. If you purchase an annual subscription for 15 credits, the cost per credit is reduced by 50% (see Annual Subscription link below). We will report all passing test scores to ISA and/or SAF. If you are a member of ISA and SAF we will report your passing test scores to both for no additional cost. Please be sure to add both of your certification numbers when you sign in. Tests with passing scores may be submitted only once to each organization.
*Members of ISA may apply the .5 CEUs toward Certified Arborist, Utility Specialist, or BCMA management credits.
California UFC members will receive credit for passing the test. Please add your CaUFC number after your ISA and/or SAF certification number.
ASCA members may submit your ISA certification record to the ASCA and receive credits one for one.
MTOA members must follow the ISA instructions indicated above.
To take the test by the pay per test option, click on the 'Pay Now' button below where you can send payment online securely with your credit card or Pay Pal account. After your payment is submitted, click on ‘Return to gibneyCE.com’. That will take you to the test sign in page followed by the test. Members with certifications from both ISA and SAF, please be sure to add both of your certification numbers. These numbers are important for reporting purposes.
To take the test as an annual subscriber with reduced rates, click on Password and enter your test password which will take you to the test sign in page. If you would like to become a subscriber see our Annual Subscription page for details.
When you have finished answering all questions you will be prompted to click ‘next’ to send your answers to gibneyCE.com. You can then click ‘next’ to view your test summary. A test review of your answers is available upon request.
All passing test scores are sent from gibneyCE.com to your organization(s) at the end of every month and they will appear on your certification record 4 to 6 weeks* after that. ISA maintains a record of CEU credits on their website. *SAF requires 5 passing test scores before reporting.
Test re-takes are allowed, however you will have to pay for the retake if you are using the pay per test option. You can spend as much time as you would like to take the test but it is important not to leave the test site until you have answered all the questions and see the 'sending your answers' response.