HR: 11:50h
AN: B22B-07    [Abstracts]
TI: Predicting Hydrogen and Oxygen Stable Isotope Ratios of Plants Across Terrestrial Surfaces: Plant IsoScapes
AU: * West, J B
EM: jwest@biology.utah.edu
AF: Department of Biology University of Utah, 257 South 1400 East, Salt Lake City, UT 84112 United States
AU: Bowen, G J
EM: gbowen@biology.utah.edu
AF: Department of Biology University of Utah, 257 South 1400 East, Salt Lake City, UT 84112 United States
AU: Ehleringer, J R
EM: ehleringer@biology.utah.edu
AF: Department of Biology University of Utah, 257 South 1400 East, Salt Lake City, UT 84112 United States
AB: Human activities at local and regional scales impact the functioning of ecological processes. Integrating these activities requires spatially-explicit models that depend on both accurate input data, as well as a mechanistic understanding of the processes being modeled. Stable isotope ratios of several elements have been used successfully as both recorders of ecological processes, and tracers of the cycling and movement of elements through the biosphere. As such they have the potential to yield useful information across multiple scales. ISOSCAPES is an effort to link ecological and physiological process models with geographic information systems in order to make and test spatially explicit predictions of stable isotope ratios for components of the biosphere. In addition to current ecological processes, we are also applying our understanding of spatial variations in isotope abundances to improve paleoclimatic and modern forensic reconstructions. We present results of our spatial predictions of δ²H and δ¹⁸O values for major plant components across the terrestrial surface of the Earth. Predictions for leaf water and cotton-boll cellulose were based on a mechanistic model of leaf water enrichment and biochemical fractionations associated with cellulose formation. The model was driven spatially with globally gridded climate normals obtained from the Climate Research Unit at the University of East Anglia, and globally gridded maps of source water isotope ratios. In addition to leaf water and cellulose, we present spatial predictions for the isotopic ratios of other plant components (e.g., seed lipids). The maps revealed significant latitudinal and continental variation that was consistent with expectations and the relatively limited spatially-explicit available data. Finally, we discuss the implications of these variations and future avenues of spatial-ecology research.
UR: http://isoscapes.org
DE: 0454 Isotopic composition and chemistry (1041, 4870)
DE: 0499 New fields (not classifiable under other headings)
DE: 0545 Modeling (4255)
DE: 1622 Earth system modeling (1225)
DE: 9399 General or miscellaneous
SC: Biogeosciences [B]
MN: Fall Meeting 2005