Stable isotopes: integrators and tracers of processes from the leaf and microbe to the atmosphere and basin.
Joe
Berry, Carnegie Institution, Dept of Global Ecology, joeberry@stanford.edu
(Presenting)
Luiz
Antonio
Martinelli, CENA, luizm@stanford.edu
Jim
Ehleringer, Univ of Utah, Dept of Biology, Jim@biology.utah.edu
The Amazon Basin by virtue of its size and the shelter provided by the High Andes to the west, is partially closed with respect to atmospheric, hydrologic and biogeochemical processes. This partial closure provides unique opportunities to study earth system processes at a scale unrivaled anywhere else on earth. Dramatic progress has been made through LBA in quantitative studies of many of these key processes. For the most part, however, these studies have focused on relatively small portions of the basin and few have attempted to encompass the entire basin. This remains as one of the challenges for the follow-on studies that build on LBA. Stable isotopes provide one approach that has already been used in basin scale integrative studies. The goal of this talk is to illustrate how stable isotope studies have provided unique insight into the functioning of the Amazon system; to review progress that has been made through LBA in extending our understanding of isotope fractionation at scales of organisms and ecosystems in Amazonia; to identify areas where work is still needed, and finally to share a vision of what isotopes might ultimately tell us about hydrologic and biogeochemical cycles in Amazonia.