Resources: Research Papers
Buée, M., De Boer, W., Martin, F., Van Overbeek, L., & Jurkevitch, E.
Plant and Soil, 321(1–2), 189–212. (2009)
The rhizosphere zoo: an overview of plant-associated communities of microorganisms, including phages, bacteria, archaea, and fungi, and of some of their structuring factors
The article presents an overview of the ecology of different microorganisms found in the rhizosphere. The rhizospheric community is complex and made out of a myriad of organisms interconnecting in numerous ways, acting upon each other and reacting to their environment. These bacterial communities in the root systems of trees are essential for the growth and survival of the tree. This study of the genetic and functional diversity and of the ecological properties of rhizosphere microbes are already yielding tangible results such as to understand the selective forces at play, the mechanisms of the action of particular microbial groups and their relationships with their biotic and abiotic environment, and as a result of this knowledge new agricultural practices and environmental consciousness are emerging.... Read more
Tags: trees, soil structure, bacterial community,
Buyantuyev, A., Wu, J., & Gries, C. (2007).
International Journal of Remote Sensing, 28(2), 269–291.
Estimating vegetation cover in an urban environment based on Landsat ETM+ imagery: A case study in Phoenix, USA
To monitor the growth, and development of urban environments, it is constantly required to analyse the various parameters contributing to it. Landscape contributions include the canopy cover/ vegetation cover. The study area is the Central Arizona–Phoenix Long-Term Ecological Research (CAPLTER) site, which is centred at the city of Phoenix, Arizona, USA. The study maps the site areas using various software techniques and analyses the patterns of growth and change in land use, while mapping them in terms of graphs. It compares all three methods for anaylsis and concludes that SMA is a rather accurate method of analysing vegetation cover.
Tags: Vegetation cover, data analysis, software, canopy cover
City of Guelph Tree Technical Manual. (2018).
City of Guelph.
City of Guelph Tree Technical Manual
The document is put together by the City of Guelph to devise a management and conservation plan for all the vegetation cover/ canopy cover in the city. It describes the general policies and norms taken into consideration. Tree inventories, plans, data analysis and reports, street tree plans, and landscape plans are covered in one of the chapters. The document also talks about protective measures for these trees along with grounds care and maintenance.
Tags: Manual, tree inventory, protection measures, compensation
Donovan, G. H., Michael, Y. L., Butry, D. T., Sullivan, A. D., & Chase, J. M. (2010).
Health & Place, 17, 390–393.
Urban trees and the risk of poor birth outcomes.
Many studies have been published on the impact of urban trees on health and lifestyle. This article particularly looks at the impact of urban trees on birth outcomes in Portland, Oregon, USA. The study emphasises the effect of trees on birth outcomes because urban trees are an important element of the natural environment that can be more readily modified than other natural amenities. For example, it is easier to plant trees in a neighbourhood than increase the size of parks or other open spaces. The results of the study do not provide direct insight into how urban trees may improve birth outcomes. However, stress reduction is a plausible biological mechanism linking trees to small for gestational age, as previous research has shown that maternal stress can increase the probability of underweight birth and exposure to natural environments can reduce stress. Read more..
Tags: birth outcomes, trees, health, stress
Environment Canada. (2014)
Ottawa.
Recovery Strategy for the Kentucky Coffee- tree (Gymnocladus dioicus ) in Canada
The study does a complete assessment of the Kentucky Coffee tree specie. Species information, population and distribution all over Canada. It talks about the conditions favourable for the tree to thrive in, and threat assessment. An entire chapter talks about the recovery of the species from the threats and also the management and conservation techniques used. The study concludes with a set of indicators to monitor the growth and progress of the trees.
Read more..
Tags: Fact file, kentucky coffee tree
Gilman, E. F., & Watson, D. G. (2014)
Florida: University of Florida. Retrieved from http://edis.ifas.ufl.edu/st287
Gymnocladus dioicus: Kentucky Coffeetree.
It is a fact file stating the uses of the tree, describing its morphology and general information. The fact file describes the morphology of the tree. It describes the leaves, bark and fruit of the tree in terms of shape, size, colour, and texture. Uses are streets without sidewalks; reclamation; shade; specimen; or highway median.
Read more..
Tags: Fact file, kentucky coffee tree, leaf physiology and description, flower, fruit, pests, management
Gorzelak, M. A., Asay, A. K., Pickles, B. J., & Simard, S. W. (2015). AoB Plants, 7.
Inter-plant communication through mycorrhizal networks mediates complex adaptive behaviour in plant communities.
The study is based on the ectomycorrhizal ecosystems and arbuscular mycorrhizal systems. It describes the relationship between trees growing in each other's proximity and how the root systems affect each other. Given the connectivity inherent in the formation of the mycorrhizal network and the impressive array of plant behavioural interactions that can be mediated through them, plant behaviour and MNs are intricately linked. Understanding these connections will enable us to characterize the connections that are important to the behaviour of system agents and thus ecosystem stability. Read more.
Tags: mycorrhizal network,
Grabosky, J., & Bassuk, N. L. (1995).
Journal of Arboriculture, 21, 187–201.
A new urban tree soil to safely increase rooting volumes under sidewalks.
It is apparent that we can grow plant materials in a load-bearing pavement base. A blend's strength is a function of the strength of stone if the stone-to-soil ratio is not lower than the critical ratio which would occur with the addition of excessive soil Currently plant materials are being grown and studied in stone/soil mixes compacted to optimum densities. Water management, nutrient availability frost-heave susceptibility, as well as root and shoot growth studies will be incorporated into these and future tests.
Read more.
Tags: Root systems, spacing, constructed infrastructure
Grabosky, Jason, Haffner, E., & Bassuk, N. (2009).
Journal of Arboriculture, 35(5), 271.
Plant available moisture in stone-soil media for use under pavement while allowing urban tree root growth.
The research looks at the moisture content under constructed infrastructure and the growth of tree root systems. The experiment looks at various media used for pavement- gravel, concrete and different kinds of structural soils to find the moisture retention capacity of each. The use or consideration of porous aggregates could be factored in when assessing irrigation needs in normal operations, but should not be assumed to be the only criterion for determining the overall performance of a mix design. Soil chemical aspects such as aggregate and soil pH and cation exchange capacity ought to be further tested and considered over time. Aggregates must function over time as the load-bearing lattice of the system.
Read more.
Tags: Structural soil, paved infrastructure, root system, moisture content
Hegedüs, A., Gaál, M., & Bérces, R. (2011).
Applied Ecology and Environmental Research, 9(4), 411-423.
Tree appraisal methods and their application–First results in one of Budapest’s districts.
The paper discusses and compares some widely applied international and Hungarian methods and takes into consideration their benefits and disadvantages. A tree survey was done in the year 2010, in one of the greenest districts of Budapest. Based on this, species composition, distribution by age of the trees, condition of the trees, and proportion of the fruit and ornamental trees were analysed and calculations were done regarding the tree values. The results showed that good judgement through experience is important in selecting the method to use, for no one method can be used under every condition. The process helps evaluate trees considering multiple affecting factors.
Read more.
Tags: distribution, composition, green districts, mapping
Jennings, S. B., Brown, N. D., & Sheil, D. (1999). Forestry: An International Journal of Forest Research, 72(1), 59–74.
Assessing forest canopies and understorey illumination: canopy closure, canopy cover and other measures.
This paper distinguishes two basic types of measurement: canopy cover is the area of the ground covered by a vertical projection of the canopy, while canopy closure is the proportion of the sky hemisphere obscured by vegetation when viewed from a single point. The principal techniques used to measure canopy cover, canopy closure, and a number of related measures are described and discussed. The importance of the forest canopy to forestry and forestry research has been reflected in the ingenuity of foresters in devising methods and instruments to measure it..
Read more.
Tags: forest cover, measurement, analysis
Koeser, A. K., Gilman, E. F., Paz, M., & Harchick, C. (2014).
Urban forestry & urban greening, 13(4), 655-661.
Factors influencing urban tree planting program growth and survival in Florida, United States.
The study evaluates different planting programs and their success across 26 sites across Florida. The map and monitor the progress of the planting programs and the benefits of the urban trees associated. it analyses various factors such as survival and tree growth for various species. The extensive data collection at 26 sites across the state, we conclude that the FFS Urban and Community Forestry Grants Program is an effective model for urban replanting efforts. This work shows that plant growth can be maximized by accounting for factors such as the season of planting, site selection, and irrigation. Read more.
Tags: Container-grown, Field-grown, Irrigation, Survivorship
Tree longevity, Tree mortality
Kopinga, L. (1991).
Journal of Arboriculture, 17(57–63).
The effects of restricted volumes of soil on the growth and development of street trees.
In many urban situations, the amount of soil available for the root growth of a street tree leaves much to be desired. Generally, the lateral spread of the root system is restricted by high soil density, which makes penetration by the tree roots nearly impossible. The study takes up different examples and studies their impact on them and does a comparative analysis.
Read more.
Tags: root barriers, soil structure
Lindsey, P., & Bassuk, N. L. (1992).
Arboricultural Journal, 16, 25–39.
Redesigning urban forests from the ground below: A new approach to specifying adequate soil volumes for street trees.
....the most debilitating conflict is between the biological needs of the trees whose root systems generally lay near the surface and spread laterally, and small confined areas they are relegated to in design of the urban streets.
Read more.
Tags: urban street trees, soil,
Lu, J. W. T., Svendsen, E. S., Campbell, L. K., Greenfeld, J., Braden, J., King, K. L., & Falxa-raymond, N. (2010).
Cities and the Environment, 3(1), 1–15.
Biological, Social, and Urban Design Factors Affecting Young Street Tree Mortality in New York City.
The study looks at the mortality of the trees planted in urban areas through various planting programs based in the Netherlands. The dimensions of a planting hole that are necessary to meet the tree's demands can be estimated based on the water balance and the nitrogen supply. In this paper, some examples are presented of dimensions calculated in this manner, with an emphasis on the supply of nutrients. The paper studies water consumption, nitrogen demands of the trees, soil structure and nutrients.
Read more.
Tags: urban forests, health, urban design, planted trees, mortality
Maas, J., Verheij, R. A., de Vries, S., Spreeuwenberg, P., Schellevis, F. G., & Groenewegen, P. P. (2009).
Journal of Epidemiology & Community Health, 63(12), 967-973.
Morbidity is related to a green living environment.
The study indicates that the previously established relation between green space and a number of self-reported general physical and mental health indicators can also be found for clusters of specific physician-assessed morbidity. The study stresses the importance of green space close to home for children and lower socioeconomic groups.
Read more.
Tags: environment, morbidity, greenspaces
McPherson, E. G. (2000).
Journal of Arboriculture, 26(6), 289-297.
Expenditures associated with conflicts between street tree root growth and hardscape in California, United States.
The study maps all urban trees in California and aspects like their health, mortality, interaction with sidewalks, repair costs etc associated with street trees. There are over 6 million street trees in California and these trees are associated with approximately $70 million in expenditures to remedy conflicts between root growth and hardscape. This is a conservative estimate because it does not include repair costs for damage to irrigation and water meters, sewer lines, building foundations, parking lots, and pavement on private property. Read more.
Tags: urban forestry, constructed infrastructure, finances,
McPherson, E. G. (2014).
Journal of Arboriculture & Urban Forestry, 40(5), 285-300.
Monitoring Million Trees LA: tree performance during the early years and future benefits.
Million Trees LA (MTLA) is one of several large-scale mayoral tree-planting initiatives in the United States, striving to create more livable cities through urban forestry. This study combined field sampling of tree survival and growth with numerical modelling of future benefits to assess the performance of MTLA plantings. Read more.
Tags: California; Carbon Monitoring; Park; Planting; Sequestration; Street Trees; Tree Growth and Mortality; Tree Planting Initiatives; Urban Forestry; Yard
McPherson, E. G., & Simpson, J. R. (2002).
Urban Forestry & Urban Greening, 1, 61–74.
A comparison of municipal forest benefits and costs in Modesto and Santa Monica, California, USA.
This paper compares the structure, function, and value of municipal urban forests in Modesto and Santa Monica, CA. The motivation for this study is to provide cities with a comprehensive accounting of municipal forest benefits and associated management costs.
Read more.
Tags: Finances, urban trees, resources, healthy trees
Mitchell, R., & Popham, F. (2007).
Journal of Epidemiology & Community Health, 61(8), 681-683.
Greenspace, urbanity and health: relationships in England.
Determine the association between the percentage of greenspace in an area and the standardized rate of self-reported "not good" health, and explore whether this association holds for areas exhibiting different combinations of urbanity and income deprivation. Although, in general, a higher proportion of greenspace in an area is associated with better health, the association depends on the degree of urbanity and level of income deprivation in an area. One interpretation of these analyses is that quality, as well as quantity of greenspace, may be significant in determining health benefits. Read more.
Tags: urban greenspaces, income, relationships
Morgenroth, J. (2008).
Arboriculture & Urban Forestry, 34(2): 84-88.
A review of root barrier research
The article describes various kinds of root barriers and their history over years- linear root barrier, circular root barrier and three-dimensional root barrier. Experiments have been carried out over decades to find suitable barriers for street trees. Studies show the importance and contribution made by these root barriers in allowing the roots to grow and expand in particular directions without hampering the curbs, sidewalks and other paved infrastructure. The most important finding to date has been the variability of root response to barriers seemingly influenced by soil type, environmental conditions, and species selection. The article also directs the future research scope in the field. Read more.
Tags: Street trees, benefits, relation with urban paved environments
Mullaney, J., Lucke, T., & Trueman, S. J. (2015). Landscape and Urban Planning, 134, 157-166.
A review of benefits and challenges in growing street trees in paved urban environments.
The article highlights the importance and benefits obtained from urban street trees. The article reviews literature based on this topic spanning over a period of 30 years. Environmental benefits, economic, stormwater and energy-related benefits are discussed in detail. The study also covers the residents' perceptions while evaluating the damage caused to the root systems due to the constructed infrastructure like pavements, etc. The article discusses the financial figures associated and the replacement costs.
Read more.
Tags: Street trees, benefits, relation with urban paved environments
Natural Resources Canada. (2015).
Retrieved September 25, 2019
Kentucky coffeetree.
The fact file describes the morphology of the Kentucky coffee tree. Its form, leaves, sizes, lengths, barks, colour, fruit, pods, wood, the form of the tree, habitat, along with photos and distribution map across the country
Read more.
Tags: Fact file, trees, insects and diseases
Nowak, D. J., Kuroda, M., & Crane, D. E. (2004). Urban Forestry & Urban Greening, 2(3), 139–147.
Tree mortality rates and tree population projections in Baltimore, Maryland, USA.
Urban tree mortality is a significant factor affecting urban landscapes. Studies show that trees in medium- to low-density residential areas exhibited low mortality rates. To understand the mortality of urban trees in neighbourhoods, this study was carried out in the neighbourhoods of Baltimore, Maryland. This study would enable to prepare of better management and conservation policies.
Read more.
Tags: urban trees, mortality,
Paletto, A., & Tosi, V. (2009).
European Journal of Forest Research, 128(3), 265-272.
Forest canopy cover and canopy closure: comparison of assessment techniques.
The study compares the canopy closures and canopy covers. It also investigates new technologies for calculating the canopy covers. The canopy cover is more likely linked to forest planning and management surveys so as to forest inventories while the canopy closure seems to have a wide area of applicability in ecologically oriented forest research, linked with canopy architecture and light regimes or solar radiation. The study uses various instruments to analyse this data. It further leaves hints for the future scope of research to describe the structure of plant canopies, to establish connections between canopy and wildlife species richness or to estimate solar radiation.
Read more.
Tags: forest, urban trees, canopy cover
Pallardy, S. G. (2010).
Academic Press
Physiology of woody plants.
The book is based on the functional systems of woody plants. Consisting of different chapters based on morphology, vegetative growth, reproductive growth, transpiration, photosynthesis, metabolic functions of the plant body and enzymes, plant hormones, absorption of water, etc are covered across the book. Each chapter describes in depth the plant functions along with examples.
Read more.
Tags: woody plant body, photosynthesis, reproductive growth
Randrup, T. B. (2005).
Journal of Arboriculture, 31(3), 114-123.
Development of a Danish model for plant appraisal.
The study is derived based on 6 models for plant appraisal in urban areas. The Danish model takes its point of departure in the replacement cost of a new tree of a reasonable size that can be purchased in a local or national nursery. Therefore, the model distinguishes between damaged trees above and below this tree size. The model considers basis value, health factor, age of the tree, and location. Through different examples of trees, the study demonstrates the use of the method. The model is relevant to trees in Nordic regions and not on trees in other extreme climatic conditions.
Read more.
Tags: Urban trees, valuation model, climate, health condition, basis value,
Randrup, T. B., McPherson, E. G., & Costello, L. R. (2001).
Urban Ecosystems, 5(3), 209-225.
A review of tree root conflicts with sidewalks, curbs, and roads.
The paper examines the impact of constructed sidewalks, curbs and other built infrastructure on the survival rate of trees planted along them. It also examines the damage caused to trees at different stages. Potential for conflicts between trees and sidewalks/curbs are high when one or more of these factors are present: tree species that are large at maturity, fast-growing trees, trees planted in restricted soil volumes, shallow top soil (hard-pan underneath top-soil), shallow foundations underneath the sidewalk (limited or no base materials), shallow irrigation, distances between the tree and sidewalk of less than 2.0–3.0 m., trees greater than 15 to 20 years old. Due to a lack of planning in this domain, the replacement costs are higher for the trees which constantly get damaged due to the constructed infrastructure.
Read more.
Tags: Urban trees, infrastructure, urban soils, finances
Resources: Articles
Lara A Roman, 2014-Jun 26, Scenario Journal
How Many Trees are Enough? Tree Death and the Urban Canopy
The essay discusses street tree mortality in terms of demographic concepts and advocates for the application of these approaches in urban forest planning. Based on an old article, it is said that the lifespan of an urban tree is 32 years and a more recent study shows that it is 13 years. Further calculations on current trends show that it would be around 7 years eventually. It is necessary to monitor the mortality rates of trees in the urban context. The added costs of replanting are high and if tree mortalities are taken care of, these finances can be used for other benefits of the city. The study also monitors the population of these tree clusters across US cities and their changing trends. More studies to support the cause are required to improve the tools available for urban forest managers to plan ahead, embedding their planting campaigns within the population dynamics of cultivated city landscapes. Read more...
Tags: Tree mortality
L. R. Costello, J. D. MacDonald, K. A. Jacobs, 1991
USDA Forest Service Gen. Tech. Rep. PSW-126.
Soil Aeration and Tree Health: Correlating Soil Oxygen Measurements With the Decline of Established Oaks
The paper studies how environmental stress on urban trees can be reduced by understanding the soil aeration required for the growth of healthy trees. As a part of the experiment methodology the researchers, measure the soil aeration status at different field locations. It measures the oxygen levels to compare the health of these trees. The results of the study show that the oxygen diffusion rate of the soil and moisture content in it are interdependent and promote healthier growth of the tree. Read more...
Tags: aeration management practices, soil aeration
Lara A Roman, John J Battles, Joe R McBride, 2016-03-01,
United States Dept of Agriculture
Urban tree mortality: a primer on demographic approaches
This report is a primer on demographic concepts applied to urban trees, with terms and analytical methods adapted to the cultivated urban landscape. It includes an overview of the uses of urban tree mortality rate data for research and management, a summary of lessons learned from ecological monitoring in other systems, and a discussion of opportunities for long-term urban forest monitoring by researchers and practitioners. Urban tree demography is essential to understanding temporal changes in urban forest systems, just as tree demography is used to analyze changes in natural forest systems. Read more...
Tags: Urban tree mortality
Sean McMinn, 2019-09-05,
NPR
Trees Are Key To Fighting Urban Heat — But Cities Keep Losing Them
Studies carried out in the US show that the income of a neighbourhood is related to the tree cover there. The neighbourhoods with cooler temperatures were the ones with maximum tree cover and high incomes. The article also mentions the health benefits of trees like longer life spans, lower levels of stress, better air quality and lower rates of cardiac disease. Taking the case of Louisville, where the studies were carried out initially, the researchers also discuss the maintenance and care of these trees, and the funds required for that. Oftentimes it is difficult to raise funds for the aftercare of trees planted. The government bodies still encourage people to plant more trees and also look after them for the betterment of their own neighbourhoods. Read more...
Tags: Tree cover, heat island effect, climate crisis, income, finances
University of Wisconsin-Madison, 2019-03-25,
ScienceDaily
Trees are crucial to the future of our cities
Studies show that the right amount of tree cover can help reduce the temperature by 10 degrees Fahrenheit. Monica Turner, a University of Wisconsin-Madison professor in the department of Integrative Biology and a co-author of the study, says that cities are generally warmer than the countryside. Climate change is forcing city planners to prepare to make cities more comfortable.
Roads absorb heat throughout the day and release heat during the night. On the other hand, trees help reduce the same effect through their canopy cover and shade, as well as transpiration.
Carly Ziter, the lead author of the paper, mentions that studies like these have tended to focus on what is known as the "urban heat island" effect. Those studies often use satellites to take ground surface temperature readings or measure air temperature within and outside the city. Studies have shown that developed, less vegetated cityscapes are much warmer than the rural lands around them.
The data shows that forty per cent canopy cover is the threshold required to trigger the large cooling effects that trees have to offer. The author adds that we should be more outspoken since the trees we plant now and their mortality will determine the temperatures of our cities in the future. Read more...
Tags: Ecosystem services, urban trees, benefits
Elise Stolte, 2016-08-01
Edmonton Journal
New soil cell technology aims to grow big trees in Edmonton's tight spaces
The article describes the trees in Edmonton, Alberta, which are grown in small pits between sidewalks and a heavily-compacted road. The mortality of these trees is high and about three years after planting there is only 40% of the canopy remaining.
They are now trying to adapt to new technology where small plastic tables stacked underground and filled with rich, un-compacted soil can give the trees the space they need, even under sidewalks or parking spaces. These alternative technologies can cost up to $16,000. Budget dollars are directed to drainage and transportation needs instead of trees. However, well-planted trees and mature canopies provide many unexpected benefits.
Edmonton has experimented with new soil cell technologies along several streets, including Stony Plain Road, 112 Avenue in the Highlands and 96 Street downtown. New soil cells shaped like plastic tables provide a compacted parking surface or sidewalk while protecting the uncompacted soil beneath. It creates long soil vaults between trees or soil bridges underneath sidewalks to allow roots to reach front yards. Read more...
Tags: technology, case study, tree mortality, ecosystem services
Resources: Articles
Lara A Roman, 2014-Jun 26, Scenario Journal
How Many Trees are Enough? Tree Death and the Urban Canopy
The essay discusses street tree mortality in terms of demographic concepts and advocates for the application of these approaches in urban forest planning. Based on an old article, it is said that the lifespan of an urban tree is 32 years and a more recent study shows that it is 13 years. Further calculations on current trends show that it would be around 7 years eventually. It is necessary to monitor the mortality rates of trees in the urban context. The added costs of replanting are high and if tree mortalities are taken care of, these finances can be used for other benefits of the city. The study also monitors the population of these tree clusters across US cities and their changing trends. More studies to support the cause are required to improve the tools available for urban forest managers to plan ahead, embedding their planting campaigns within the population dynamics of cultivated city landscapes. Read more...
Tags: Tree mortality
L. R. Costello, J. D. MacDonald, K. A. Jacobs, 1991
USDA Forest Service Gen. Tech. Rep. PSW-126.
Soil Aeration and Tree Health: Correlating Soil Oxygen Measurements With the Decline of Established Oaks
The paper studies how environmental stress on urban trees can be reduced by understanding the soil aeration required for the growth of healthy trees. As a part of the experiment methodology the researchers, measure the soil aeration status at different field locations. It measures the oxygen levels to compare the health of these trees. The results of the study show that the oxygen diffusion rate of the soil and moisture content in it are interdependent and promote healthier growth of the tree. Read more...
Tags: aeration management practices, soil aeration
Lara A Roman, John J Battles, Joe R McBride, 2016-03-01,
United States Dept of Agriculture
Urban tree mortality: a primer on demographic approaches
This report is a primer on demographic concepts applied to urban trees, with terms and analytical methods adapted to the cultivated urban landscape. It includes an overview of the uses of urban tree mortality rate data for research and management, a summary of lessons learned from ecological monitoring in other systems, and a discussion of opportunities for long-term urban forest monitoring by researchers and practitioners. Urban tree demography is essential to understanding temporal changes in urban forest systems, just as tree demography is used to analyze changes in natural forest systems. Read more...
Tags: Urban tree mortality
Sean McMinn, 2019-09-05,
NPR
Trees Are Key To Fighting Urban Heat — But Cities Keep Losing Them
Studies carried out in the US show that the income of a neighbourhood is related to the tree cover there. The neighbourhoods with cooler temperatures were the ones with maximum tree cover and high incomes. The article also mentions the health benefits of trees like longer life spans, lower levels of stress, better air quality and lower rates of cardiac disease. Taking the case of Louisville, where the studies were carried out initially, the researchers also discuss the maintenance and care of these trees, and the funds required for that. Oftentimes it is difficult to raise funds for the aftercare of trees planted. The government bodies still encourage people to plant more trees and also look after them for the betterment of their own neighbourhoods. Read more...
Tags: Tree cover, heat island effect, climate crisis, income, finances
University of Wisconsin-Madison, 2019-03-25,
ScienceDaily
Trees are crucial to the future of our cities
Studies show that the right amount of tree cover can help reduce the temperature by 10 degrees Fahrenheit. Monica Turner, a University of Wisconsin-Madison professor in the department of Integrative Biology and a co-author of the study, says that cities are generally warmer than the countryside. Climate change is forcing city planners to prepare to make cities more comfortable.
Roads absorb heat throughout the day and release heat during the night. On the other hand, trees help reduce the same effect through their canopy cover and shade, as well as transpiration.
Carly Ziter, the lead author of the paper, mentions that studies like these have tended to focus on what is known as the "urban heat island" effect. Those studies often use satellites to take ground surface temperature readings or measure air temperature within and outside the city. Studies have shown that developed, less vegetated cityscapes are much warmer than the rural lands around them.
The data shows that forty per cent canopy cover is the threshold required to trigger the large cooling effects that trees have to offer. The author adds that we should be more outspoken since the trees we plant now and their mortality will determine the temperatures of our cities in the future. Read more...
Tags: Ecosystem services, urban trees, benefits
Elise Stolte, 2016-08-01
Edmonton Journal
New soil cell technology aims to grow big trees in Edmonton's tight spaces
The article describes the trees in Edmonton, Alberta, which are grown in small pits between sidewalks and a heavily-compacted road. The mortality of these trees is high and about three years after planting there is only 40% of the canopy remaining.
They are now trying to adapt to new technology where small plastic tables stacked underground and filled with rich, un-compacted soil can give the trees the space they need, even under sidewalks or parking spaces. These alternative technologies can cost up to $16,000. Budget dollars are directed to drainage and transportation needs instead of trees. However, well-planted trees and mature canopies provide many unexpected benefits.
Edmonton has experimented with new soil cell technologies along several streets, including Stony Plain Road, 112 Avenue in the Highlands and 96 Street downtown. New soil cells shaped like plastic tables provide a compacted parking surface or sidewalk while protecting the uncompacted soil beneath. It creates long soil vaults between trees or soil bridges underneath sidewalks to allow roots to reach front yards. Read more...
Tags: technology, case study, tree mortality, ecosystem services