HR: 1340h
AN: H53E-0524    [Abstracts]
TI: Optimal Rooting Profiles in Water-Limited Ecosystems
AU: * Collins, D B
EM: daniel_@mit.edu
AF: Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139 United States
AU: Bras, R L
EM: rlbras@mit.edu
AF: Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139 United States
AB: Plant rooting profiles vary with climatic, edaphic and physiological factors, which, in water-limited ecosystems, has been largely attributed to hydrotrophism. However, current field data provide only a qualitative explanation, and are limited in their range of environmental variables. This study tests whether the hydrotrophic model is sufficient to explain observations of rooting profiles quantitatively, and to elaborate on the causal factors affecting them. A 1-D soil-vegetation-atmosphere transfer model, which resolves the vertical distribution of roots within the soil, is presented. Through sensitivity analysis optimal rooting profiles are identified for given environmental and plant parameters, and these vary consistently with field observations. The results also show that rooting profile affects hydrologic fluxes. A possible implication of this study is that as climate changes, rooting profiles may change too, either by plant acclimation or changes in community structure, in turn affecting both hydrologic and biogeochemical cycling.
DE: 1807 Climate impacts
DE: 1813 Eco-hydrology
DE: 1851 Plant ecology (0476)
DE: 1866 Soil moisture
SC: Hydrology [H]
MN: Fall Meeting 2005