The effect of warming on tropical forest gas exchange.
Chris
Eric
Doughty, UC Irvine, cdoughty@uci.edu
(Presenting)
Michael
L.
Goulden, UC Irvine, mgoulden@uci.edu
Further research is required to understand the sensitivity of tropical forest to climate warming. Previous research has shown that tropical forest photosynthesis decreases and respiration increases at high leaf temperatures and that tree growth is reduced in years with higher average air temperatures (Clark et al 2003). Models indicate that the climate related destruction of the Amazon forest will amplify global warming by 1.5˚ C, resulting in a mean temperature increase of 5.5˚ C, as compared with 4˚ C without this carbon cycle feedback (Cox et al 2000). These studies demonstrate the importance of temperature on tropical forest gas exchange. I propose research within NASA’s LBA experiment to better understand how tropical forests respond to high temperatures at several spatial and temporal scales. I propose field measurements at the LBA Tapajos km 83 site to determine what controls tropical leaf temperature and how temperature affects photosynthesis and respiration. I will conduct a warming experiment that will raise the temperature of leaves by 2˚-3˚, and will allow me to determine if leaves acclimate to higher temperatures. I will compare the results of the leaf level studies to data from a nearby eddy flux tower to determine if the response to temperature is similar at both the leaf and canopy levels. I will use MODIS Land Surface Temperature images to quantify the spatial and seasonal patterns of forest temperatures and see whether deforestation warms nearby intact forests. Finally, I will incorporate the results of these studies into the CLM (common land model) to determine how warming affects tropical forest CO2 and water vapor exchange.
Submetido por Christopher Eric Doughty em 23-MAR-2004
Tema Científico do LBA: CD (Armazenamento e Trocas de Carbono)