The ecology of urban forests

Forests in urban and suburban environments share many of the characteristics of other forests discussed in this volume, particularly their structure and function. For those involved in the modern science and practice of forest ecology, urban forests present unique challenges and opportunities due to the intensity and duration of human–forest interactions. Urban forests are composed of trees growing in parks, natural areas, along streets and in gardens within a matrix of buildings, roads and waterways, all of which exist primarily due to the actions of humans. The development of the discipline of forest science was driven by the increasing world demand for wood products in the eighteenth and nineteenth centuries, and most early foresters were focused on ‘natural forests’ or plantations and were uninterested in trees and forests in built environments (Miller 1988). Due mainly to the belief in the now outdated paradigm that humans were not components of ecosystems, this lack of interest in human settlements was also shared by the emerging, closely related scientific discipline of ecology (McDonnell 2011). As a consequence of the current rate and magnitude of the growth of urban areas around the globe, there is an increasing recognition of the need to create and maintain green, liveable, biodiversity rich, healthy and sustainable cities and towns (Forman 2014). Everyone involved in the science and practice of urban forest ecology and urban forestry has an opportunity to make significant contributions to the design, creation and management of sustainable human settlements in the future.