Contact Us

Email us
Phone: +1.678.367.0981
Fax: +1.240.547.1795

Mailing Address

International Society of Arboriculture
PO Box 191
Annapolis Junction, MD 20701
United States

Physical Address

International Society of Arboriculture
270 Peachtree St NW, Suite 1900
Atlanta, GA 30303
United States

Order Delays Due to Physical Inventory

Due to ISA's annual physical inventory, orders placed between
2 p.m. EDT, Thursday, 20 June 2019, and 11:59 p.m. EDT, Friday 28 June 2019, will not ship until the week of 1 July 2019

Please plan your ordering accordingly.

We will resume regular turnaround times
1 July 2019.

Thank your for your patience.

Questions? Please call the customer service team at (678) 367-0981.

    Climbers' CornerTree Academy

    A tree is not a tree is not a tree –Urban Planning and Trees


    Throughout the urban landscape, trees make up important elements of the overall green infrastructure – providing us with numerous ecosystem services of which we depend on as a community.  Trees also help us orientate and relate to the spatial context around us, creating an architectural transition from bold and often large scale buildings down to ground level as experienced by man. In the past, city trees would mirror the prosperity and cultural affluence of a society and as such, trees were planted mainly for beautification and aesthetics. Today, we know that the qualities of the urban tree stock reach beyond these concepts. With current challenges of climate change and rapid urbanization, the focus on trees has shifted towards many of the regulating ecosystem services much needed in the urban landscape. The role of urban trees today and in the future will thus be to help mitigate the urban heat island effect, shade buildings and thus reducing energy consumption, slow down surface runoff, act as noise filters, and purify the air through capturing particulate matter, carbon dioxide, ozone and other air pollutants originating from traffic and industrial activities. Whilst such services are generally measurable, urban trees also provide for more boundless qualities increasing recreation, health and wellbeing for the community – and yes, aesthetics too.


    However, in order to plan and subsequently secure a sustainable succession and development of our urban trees, we need to reach a better understanding and increase our knowledge of how different species respond in different situations – all in order to provide for different ecosystem services. With the limited space in towns and cities, and with current and future change occurring in climate and pattern of urbanization, multi-functionality and reliable plant material will become increasingly important. As such we need to begin a new discourse where focus is directed towards what kind of tree species we are using and from which cultivar the species originate? For the urban tree planner and landscape professional, a better understanding of the indigenous background and strategy of different tree species will in the end provide a robust platform from which decisions can be made in order to plan, design, and manage a sustainable urban landscape. With examples of how to link biological tree strategies as found in nature to the current urban context the presentation will provide some illustrative examples from eastern Europe, China, and the U.S. and how knowledge from nature will help in the selection of site adapted species choice for different urban environments.




    Dr. Henrik Sjoman is working as a researcher and lecturer at the Swedish University of Agriculture in Alnarp, Sweden, and finished his PhD-thesis in 2012 with the title “Trees for tough urban sites – learning from nature”. His research interest is in plant-knowledge and plant-use in urban environments with special interest towards trees. In his research he tries to find guidance in the work of finding right trees for right site and condition by studying trees in their natural environment and to learn their strategies in order to survive and compete successfully in the urban landscape. His work includes several field-expeditions to study trees in their natural/indigenous environment and thereafter collect right genotypes of the studied species for further evaluation. Fieldworks have been carried out in China, Romania, Moldavia, Caucasus and USA. In collaboration with the Swedish nursery industry the collected trees are now under further evaluation in order to release suitable trees for urban conditions in the Scandinavian region. At the university campus in Alnarp a 4 hectare large field trial area have been established in order to carry out the evaluation. So far over 200 different trees and shrubs are tested. The goal is not only to find hardy and healthy trees that can help to improve species diversity in the urban environment (in e.g. Sweden), it is equally important to know what kind of ecosystem services these trees will deliver – an important aspect seldom included in large scale tree selection programs. Henrik´s presentation will focus on bridging knowledge from natural environments to different urban sites in order to select apropriate species for e.g. warm and dry sites in paved environments, trees for sustainable storm water management, trees better for structural soils etc.    

    Climbers' CornerTree Academy

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