Thursday, August 6, 2009 - 1:30 PM

OOS 41-1: The interaction between urban land-use and climate change

Richard V. Pouyat, USDA Forest Service

Background/Question/Methods

Urban land-use change can affect ecological systems through altered disturbance regimes, landscape management practices, built structures, and altered environments (heat island, pollution, non-native species, loss of native species).  As a result of these alterations, the conversion of native to urban ecological systems has been shown to significantly affect carbon, nitrogen, and water cycles at local, regional, and global scales.  These changes have created novel ecosystems, which have no analogue in the history of life.  Nonetheless, some of the environmental changes occurring in urban areas are analogous to the changes expected in climate by the end of the century, e.g. atmospheric CO2 and increase in air temperatures. 

The similarity of environmental changes between urban land-use and climate change suggests the potential to utilize urban habitats as “whole ecosystem” manipulations whereby the effects of climate change can be investigated on entire ecosystems, thus capturing the potential to assess feedbacks occurring within ecosystems or interactions with other environmental factors (e.g., pollution).  In addition, as analogues of expected future environments, urban ecological systems may serve as reservoirs of plant and animal species for adjoining landscapes that are expected to undergo rapid climate changes in the next 100 years.  Urban land-use change by itself may contribute to changes in regional weather patterns and long-term changes in global climate, which will depend on the native systems being effected and the comparison of per capita “footprints” between urban, suburban, and rural inhabitants.

My objectives for this presentation are to 1) assess the impact of changes in urban land-use on climate change and in turn how climate change may affect urban ecological systems, 2) discuss the potential for urban ecosystems to mitigate green house gas emissions, and 3) provide examples of how native remnants embedded within urban landscapes can serve as whole ecosystem manipulations representative of climate change.

Results/Conclusions

Urban ecological systems have the potential to serve as analogues of future climate scenarios and thus represent an important opportunity to assess the effects of climate change on entire ecosystems.  Land-use changes caused by urbanization may contribute to climate change, although the net effect will vary depending on the native system replaced.  Urban ecological systems, which can be highly altered, have exhibited high biological activity and species richness and thus have the capacity to provide ecosystem services to urban residents.  However, the resiliency of these services to changes in climate will need to be enhanced through ecological engineering and restoration.