Urban Patterns and Ecosystem Function

Abstract

Urbanizing regions present challenges to ecosystem ecology, but the field may gain important insights from studying these areas. Earth's ecosystems are increasingly influenced by urbanization, and their functioning is dependent on the landscape patterns emerging in urbanizing regions. While ecosystem ecology still lacks a theory of ecosystem function that explicitly takes spatial phenomena into account, increasing empirical evidence indicates that the linkages between ecosystem structure and function depend on landscape heterogeneity (Lovett et al. 2005). Landscape heterogeneity is a spatial phenomenon caused by variation in environmental conditions. In turn, it affects the interactions among patches, biodiversity, and ecosystem processes such as energy flows, nutrient cycling, and primary production. Landscape heterogeneity manifests as discrete patterns and gradients across multiple spatial scales, and it matters to populations, communities, and ecosystems. Urban landscapes exhibit unique spatial patterns, and thus a distinctive heterogeneity. Since the amount and form of urban development affect the mosaic of habitat patches and their ecological properties, we expect alternative urban patterns to have different effects on ecological systems (Alberti 2005). These relationships are not simple, however. Urban development affects simultaneously habitat structure and the processes that control patterns of species diversity and abundance including species interactions, microclimate, and availability of natural resources (Rebele 1994, McDonnell et al. 1997, Pickett et al. 2001, Shochat et al. 2006). Thus, understanding urban landscape patterns is critical to integrating the study of ecosystem processes at multiple scales.