Applying Ecosystem Management to Urban Forestry

During the 1990s, the United States Department of Agriculture Forest Service shifted from commodity production management to ecosystem-based management (Overbay, 1992). Although definitions of ecosystem-based mana-gement vary by objectives, the principle had four primary elements: (1) maintaining viable populations of native species, (2) representing native ecosystems across their range of natural variability, (3) maintaining ecosystem processes, and (4) ensuring ecosystem goods and services for future human generations (Grumbine, 1994). In general, ecosystem management approach becomes a way of thinking more broadly about a system (Yaffee et al., 1996). For example, a forester must consider how management activities affect not only timber production but also ecosystem processes, biodiversity, and natural populations, all of which influence forest productivity. This way of thinking enables managers to look at the entire forest as a single entity and assess how management goals and objectives affect ecosystem integrity. During the 1990s, urban forestry in the United States began to shift from single-tree to ecosystem-based management (Zipperer et al., 1995). This new approach recognizes the importance of urban vegetation (both public and private) as part of the urban ecosystem and as a source of many ecological services and benefits (Nowak and Dwyer, 2000). These benefits include cleaning air and water, enhancing human health, and providing wildlife habitat, recreational opportunities, and aesthetics. By taking an ecosystem approach to management, urban foresters can maximize benefits from the forest while minimizing the cost to maintain it. Yet, an urban forester manages by altering the structure of only public trees through single-tree management. Does this mean that an ecosystem-based management is not a viable objective for urban forest management? Throughout the International Symposium on Urban Forestry and Eco-Cities held in 2002, speakers promoted the need to take a holistic approach to management and the need to better understand the social and ecological processes influ~ncing the livability of a city. This chapter provides a succinct overview of ecosystem principles as they pertain to urban landscapes, and applies the theory of vegetation dynamics as a means of clarifying for managers how they may take a holistic approach through single-tree management.