PARENT SESSION
Oral Session #20: Urban Ecosystems: Comparisons Across Biomes, Patterns and process.
Presiding: M. Carreiro
Monday, August 5. 1:00 PM to 3:45 PM. Grand Ballroom West, Radisson.
Carbon fluxes in an urban ecosystem compared to adjacent grasslands and agriculture.
Kaye, Jason*,1, Burke, Ingrid1, 1 Colorado State University, Fort Collins, CO
ABSTRACT- Urbanization is a widespread type of land-use change that, until recently, received little attention from ecosystem ecologists. In the Front Range of Colorado, the burgeoning urban metropolis derives new land from adjacent prime agricultural land or unmanaged grasslands. We measured soil respiration and aboveground herbaceous net primary production in urban ecosystems and nearby dryland agriculture, irrigated agriculture, and unmanaged grasslands in north-central Colorado. Replicated field measurements showed that soil respiration in urban ecosystems (2800 g C m-2 yr-1) was three times greater than fluxes from unmanaged grasslands or irrigated agriculture (920 and 1140 g C m-2 yr-1, respectively) and 4 times greater than dryland agriculture (510 g C m-2 yr-1). Urban ecosystems maintained high soil respiration rates from April to October, while other ecosystems reached short-lived maxima in May (unmanaged grasslands and dryland agriculture) or July (irrigated agriculture). Herbaceous primary production was greatest in irrigated agriculture, followed by urban ecosystems, unmangaged grasslands, and dryland agriculture. These data suggest that rapid urbanization during the past 5 decades has altered the regional carbon budget.
KEY WORDS: urban, ecosystem, carbon, respiration