M.R. Rosen and W.A. Kenney
As much as people around the world think of Canada as a "Forest Nation" or a "Forest People", in reality 78% of Canadians live in urban centres. For most Canadians, the forest they most closely associate with are the woodlot remnants, riparian borders and street trees that constitute the urban forest. The impetus for urban forestry came through an impending crisis - the wake-up call of the loss of the American elm (Ulmus americana L.) to Dutch elm disease in the 1960s. At the Fifth Canadian Urban Forest Conference held in October 2002, practitioners gave greater direction to this newly emerging science. As the pressures on the urban forest increase, they articulated the desire to see amongst other things, the federal and provincial government, universities, and private sector play a greater role in this increasingly important field. This paper looks at current trends in urban forestry in Canada.
So much land
Canada contains 10% of the world's forests (Canadian Forest Service, 1993) which until recently, was the basis of the Canadian economy. This explains why "industrial forestry" has continued to dominate the programs that define "forestry" within Canada. Historical reviews frequently describe the progress in Canadian forestry - going from the "Prehistoric" to the "Liquidation" to the "Conservation" to the "Sustained Yield Eras" (Apsey et. al., 2000).
It is amidst this history that the development of Canada's cities took place. From a population of 5 million in 1901 in which 80% of the population lived on farms and in rural areas, Canada has now attained a population of over 30 million of which 78% live in cities, towns and populated areas. This change has been accompanied by urban infrastructure changes - including more streets, sewers, underground services (gas, electricity and water) and of course, buildings.
Figure 1. Most Canadians (78%) live in urban areas.
Municipal tree planting began along roadsides. At the turn of the 20th Century, many municipalities began to see the need to protect and replant trees. The creation of municipal parks departments and agencies to manage vast tracts of public, urban land was a response to these phenomena. Monoculture type plantings were common. Highway and road construction rarely considered the integration of trees in site designs. New development in agricultural and natural areas (including woodlots) surrounding cities in the post-World War II era quickly mirrored the "Liquidation Phase" of industrial forestry - forests were seen as an impediment to growth and quickly eliminated to accommodate suburban expansion.
The arrival of Dutch elm disease in the early 1960's virtually wiped out the American elm (Ulmus americana L.) the street tree of choice in Canada's cities. From this an urban forestry movement was born including the creation of a number of organizations - from community groups such as SOS Elms in Manitoba to the creation of an Urban Forestry Program of the federally sponsored Forest Management Institute in 1973 (Jorgensen, 1993). It was as Chief of that program that Eric Jorgensen, considered by many to be the grandfather of urban forestry invented its first working definition:
Urban forestry is a specialized branch of forestry and has as its objective the cultivation and management of trees for their present and potential contribution to the physiological, sociological. and economic well being of urban society. These contributions include the over-all ameliorating effect of trees on their environment, as well as their recreational and general amenity value (Jorgensen, 1993)
Over the years, many other definitions have been proposed, most recognizing the difficulty in limiting the urban forest to the "city" limits (van Wassenaer, 2000). In addition, the woodlands in the vicinity of Canada's cities and towns face significant pressures from urbanization. Forests in these "peri-urban" environments tend to be highly fragmented and the rate at which they are permanently lost from the landscape is great. In this sense, these woodlands are also part of our urban forests.
Academic support initiated in this same period included the creation of the Shade Tree Research Laboratory at the University of Toronto and later the development of the precursor to the Ontario Urban Forest Council - the Ontario Shade Tree Council. Under the auspices of the federal Green Plan in 1992, the federal government saw it necessary to help create the Tree Canada Foundation to amongst other things, "encourage Canadians to plant and care for trees in urban and rural environments and in so doing contribute to the reduction of harmful effects of carbon dioxide emissions" (Tree Canada Foundation, 1992).
Many may argue that the conventional image of Canada's forests is disconnected from reality. Few Canadians own recreational properties (cottages) or seek wilderness experiences in Canadian forests - fewer still make their livelihood from wood-using industries. As such, the urban forest where 78% of Canadians live and work represents the primary interface between the vast majority of Canadians and their natural heritage. If there is an urban disconnect from forest issues and rural forest communities, then the urban forest is the logical place to begin to reconnect urbanites to nature.
Because 80-90% of the urban forest is in private residents' front and backyards rather than city parks or street sides, it is essential that homeowners are aware of the issues of urban forest sustainability and are directly involved in it. Urban Canadians are not oblivious to the forest around them. On the contrary, a recent poll indicated that 84% of Ontario urbanites felt that the trees and woodlands in and near their communities were extremely important to them (Environics, 2001). Similar numbers of respondents indicated that they were concerned about the health and vitality of these forests.
Urban forestry has since gone through a number of changes and developments since the 1960's including: the growth of the arboricultural industry, the establishment of municipal tree advisory committees, the employment of professional foresters in most Canadian cities, the passing of tree cutting bylaws, the growth in inventory and other management systems and the creation of agencies to (amongst other things) manage urban forests including the Commission de la Capitale nationale in Québec City, National Capital Commission in Ottawa, the Wascana Centre Authority in Regina, Saskatchewan and many others. Other technical innovations in urban tree installation and naturalization techniques were pioneered in Canada as well.
Figure 2. Installation of hackberry (Celtis occidentalis L.)
In a winter salt-prone area, Ottawa, Canada.
Urban forests provide a broad array of well-known environmental, economic, and social benefits to these Canadians. For example:
Sequestering of gaseous air pollutants and particulates (Klaus et al. 1998; McPherson 1991; Nowak 1994a; Smith 1990; Von Stulpnagel et al. 1990; Kenney et al., 2001).
Energy conservation through transpirational cooling, shade, and wind reduction (Akbari and Taha 1992; McPherson 1994; Brown and Gillespie 1995).
Storm-water attenuation (Sanders 1984; Xiao et al. 1998).
Noise buffering (Huang et al. 1992: Long-Sheng et al. 1993)
Provision of wildlife habitat (DeGraaf 1985)
Increased property value (Petit et al. 1995)
Improved aesthetics (Schroeder and Cannon 1987), and
Psychological well being (Ulrich et al. 1991; Schroeder and Lewis 1991)
Figure 3. The economic value of trees to Toronto
Is in the billions of dollars
The economic value of these benefits is enormous. Based on a recent analysis in the City of Toronto, with a canopy cover of 21%, very close to the average for eastern North American cities (Kenney et al., 2001) residential areas have approximately one tree per person. Based on an average Council of Tree and Landscape Appraisers (1992) value of $700 per tree (Kenney and Idziak 2000) this would make an approximate replacement value of the urban forest at over $16 billion. Similarly, the replacement value of the municipally owned street trees would be in the order of $3 billion. The reader is cautioned that this value represents the replacement cost based on species, size, location and condition and does not reflect the monetary benefit to society.
Clearly, urban forests have a substantial monetary benefit to the municipalities, provincial and federal governments (storm water attenuation, air quality mitigation, tourism, health care costs, etc.), to residents (property value, energy conservation, etc.) and business (tree care companies, nursery industry, aesthetics of retail areas). Internationally, many cities are recognizing that their urban forests will play an important role in their competitiveness to attract business and industry.
The benefits listed above accrue not only to the owners of the trees and forest but also to the entire community. While the same can be said for the wildland forests of Canada, the connection in the urban forest is much more obvious and dramatic because the beneficiaries live within it. A recent trend has been to evaluate trees, shrubs and greenspace by applying economic models to what is increasingly known as "green infrastructure". Programs such as City green (American Forests, 2002) which estimate the economic benefits of greenspace allow decision makers to better understand the implications of their planning decisions.
The threats to the urban forest in Canada are both physical and political. They include:
Urbanization of natural, wooded areas outside of cities - converting woodlots into either a non-treed environment or a single-tree environment
Loss of topsoil in land development which therefore prejudices tree growth
Exotic pest, disease and invasive plant introductions including Dutch elm disease, Asian gypsy moth and European buckthorn
Expansion of urban infrastructure (roads widenings etc.) with resulting negative impacts on trees
The use of trees and plant material of unknown provenance thereby increasing susceptibility to increased mortality
Increasing drought, salt pollution in the winter and air pollution problems, and
A lack of credible leadership, both governmental and academic to lead in urban forestry work in Canada.
In Canada, the management of urban forest resources rests in the hands of local municipalities. There are few, if any, policies, regulations, laws or other instruments in place at the provincial or federal levels that govern the sustainable management of the urban forest.
Increasingly, the private sector and non-governmental organizations have been called upon to help disseminate information and deliver programs including tree planting to Canadian communities (Rosen, 2002). Millions of dollars are allocated by Canadian companies, largely in the energy and retail sectors to support tree planting activities. Frequently, it is left to non-governmental organizations and/or municipalities to coordinate the work on behalf of these companies.
Participants at the Canadian Urban Forest Conference identified the following as important initiatives to address some of the challenging issues facing Canada's urban forests. These include:
Promoting the application of cost/benefit analyses for urban forests in Canada
Examining taxation and incentive programs to promote good urban forestry practice by individual, municipalities, developers and builders.
The need for a fully funded national body to serve as a catalyst for research, communications, education and advocacy and as a clearinghouse for information.
The need to raise the level of awareness of urban forestry issues (benefits and challenges) to the public at large, other professions, and policy makers.
Having good science available to support urban forestry decision-making.
Articulating a consistent vision for urban forests across the country, identify achievable goals and monitor progress towards these goals with a standard set of criteria and indicators.
Actively planning for sustainable urban forests
Achieving parity with other infrastructure components of the urban fabric
Providing leadership for community action
Optimizing tree selection for the urban and peri-urban environment
Developing linkages between groups involved in urban forestry across the Country
By shear will and innovation, Canada has persevered in being a leader in urban forestry work. However, it still has a long way to go. Surveys of Canadian municipalities indicate that most do not have strategic urban forest plans in place (Kenney and Idziak 2000).
Table 1. 1999 survey of 600 Canadian communities asking them if they had a strategic urban forest plan - grouped in population classes.
Many do not even have effective inventories. Since the vast majority of the urban forest is situated on private land, the paucity of data on the resource as well as the lack of planning strategies for its protection and enhancement is much greater than illustrated by simply looking at the level of management by municipalities.
Urban forestry in Canada is, in effect, an entity of the local municipality. While organizations such as the International Society of Arboriculture promote the exchange of information among practitioners, no formal mechanism exists to ensure an effective, on-going exchange of information among municipalities. Except for some planting programs implemented through NGO groups such as the Tree Canada Foundation and efforts to deal with specific crises in the urban forest (i.e. emerald ash borer), the provincial and federal governments provide little leadership in urban forestry.
Urban forestry courses are provided at some universities such as the University of Toronto. However, insufficient attention is given to the training of professionals who can address the broad array of challenges meeting urban forest managers. Just as other professions play an important role in the management of wildland forests, professionals also have a role to play in urban forest management. A groundswell is developing in Canada's urban forestry community for greater recognition and funding. Time will tell what progress will be made in time for the 6th Canadian Urban Forest Conference in 2004.
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Foundation, 220 Laurier Ave. W., Ottawa, Ontario, Canada. Email: [email protected];