HR: 1340h
AN: B43B-1159    [Abstracts]
TI: Predictability and detectability of biogeographic changes in plant distributions
AU: * Gutschick, V P
EM: vince.gutschick@gmail.com
AF: Global Change Consulting Consortium, 4904 Calabazilla Rd., Las Cruces, NM 88011, United States
AB: Rapid climatic changes are envisioned as atmospheric composition is changed by human activities. These changes have long been predicted to drive large-scale changes in the distribution of plants and of all their associated biota. The direct effects of increasing atmospheric CO₂ on photosynthesis, transpiration, and nutrient dynamics have also been predicted to alter the abundance and density of whole functional groups of plants, particularly those differing in photosynthetic pathways (increases in C₃ plants at the expense of C₄s, as one considerable simplification). In recent work, I have pointed out major physiological diversity among individual plant species in their direct responses to elevated CO₂. The consequences include considerable fragmentation in migration patterns of plant species over decades to centuries. Refining the predictions is a daunting task largely in the areas of physiology, ecology, and evolution. Detecting the changes for validation of predictions and for management/ response strategies is similarly a major challenge. Many changes in plant performance and distribution driven directly by climate and CO₂ are modest to date, given the modest scale of changes in these two drivers over decadal time scales amenable to both field studies and remote sensing. Large-scale changes, such as in growing season, have occurred but species details have not been resolved in observations with global, repeated coverage. Additional large-scale studies, to merge with small-scale studies, are needed. I review briefly the feasibility of remote-sensing studies for such purposes. For limited campaigns, there is the potential for resolving species by spectral signature, using advance hyperspectral sensing coupled with biophysical models. More general remote-sensing technologies allow detecting shifts between functional types (e.g., grass/woodland) at ecotones, and shifts at all locations in physiological stresses - particularly water stress in its temporal and spatial spectra - directly or via changes in gross primary productivity.
DE: 0410 Biodiversity
DE: 0439 Ecosystems, structure and dynamics (4815)
DE: 0466 Modeling
DE: 0476 Plant ecology (1851)
DE: 0480 Remote sensing
SC: Biogeosciences [B]
MN: 2007 Fall Meeting