10.6
A Portable Chamber System For Measurements of Whole-System CO2 Flux in Remote Montane Ecosystems
Brett T. Greene, Yale University, New Haven, CT; and A. C. Kerr and X. Lee
In mid-latitude mountain regions, global warming models predict decreased winter snow events, earlier spring snowmelt, and a higher incidence of summer droughts. These conditions can lower soil moisture, shift vegetation composition, and in turn, alter whole system carbon fluxes. However, highly varied mountain topography constrains the predictive power of global climate models and nutrient cycling models in mountain ecosystems. To better understand the effects of topography and microclimate on carbon cycling, we sampled CO2 net ecosystem exchange (NEE) along an elevation gradient in montane meadows near the Rocky Mountain Biological Laboratory, Colorado, during the 2001 summer field season. We created a profile of diurnal and seasonal fluctuations, and tested the steady-state assumption of carbon flux using coefficients of plant productivity, soil litter contributions, and litter recalcitrance. It appears that changes in CO2 flux under predicted global warming may result in positive feedback to the atmosphere, escalating and accelerating atmospheric radiative forcing.
Session 10, Carbon dioxide exchange Part 2
Friday, 24 May 2002, 8:30 AM-11:45 AM
Previous paper Next paper