HR: 1340h
AN: B33B-1209    [Abstracts]
TI: Evapotranspiration and River Discharge Interactions With Fire, Partial Success Restoration, and Climate Change
AU: * Cleverly, J R
EM: cleverly@sevilleta.unm.edu
AF: University of New Mexico, UNM Biology Dept MSC03 2020 1 University of New Mexico, Albuquerque, NM 87131-0001, United States
AU: Teet, S B
EM: steet421@unm.edu
AF: University of New Mexico, UNM Biology Dept MSC03 2020 1 University of New Mexico, Albuquerque, NM 87131-0001, United States
AU: Thibault, J R
EM: jrtebo@sevilleta.unm.edu
AF: University of New Mexico, UNM Biology Dept MSC03 2020 1 University of New Mexico, Albuquerque, NM 87131-0001, United States
AU: Dahm, C N
EM: cdahm@sevilleta.unm.edu
AF: University of New Mexico, UNM Biology Dept MSC03 2020 1 University of New Mexico, Albuquerque, NM 87131-0001, United States
AB: Climate change is likely to have profound effects on water supplies in the southwestern United States. The largest rivers in this region are fed by snowmelt, which is predicted by the IPCC to decrease over the coming years. In the Middle Rio Grande of New Mexico, transpiration from phreatophytic vegetation can represent up to one-third of annual depletions. A flux tower network has been established in New Mexico, termed NM-EPSCoR Fluxnet, is providing valuable information on the eco-hydrological response of riparian and upland ecosystems to climate events (like drought), topographically-driven mesoscale forcing from katabatic and anabatic winds, ecosystem restoration, and post-fire recovery ecology. Following removal of non-native from below a cottonwood canopy causes greater insolation of the soil surface, doubling ground heat flux rates and inverting a portion diel energy balance from a heat sink (i.e., H < 0) to a heat source. The strongest cross-correlation (r = 0.5) between river flow and ET was observed when discharge was lagged 14 days behind ET. Neither drought nor fire modified this lag relationship. However, correlation between discharge and ET disappeared entirely following a canopy fire in 2006. Stomatal resistance cottonwood and co-occurring native and non-native vegetation was most strongly limited by vapor pressure deficit, although stomatal resistance was typically measured below this limit because of these plants' access to groundwater. It is also because of abundant groundwater along the Middle Rio Grande that drought has little effect on water and energy fluxes. As climate changes in this region and groundwater becomes more scarce, changes in community composition to non-native species is expected as native species become isolated from groundwater. With a strong understanding of the factors controlling the riparian water cycle, management of the riparian corridor can be achieved such that depletions are minimized while value of the ecosystem services can be maintained.
DE: 0426 Biosphere/atmosphere interactions (0315)
DE: 0483 Riparian systems (0744, 1856)
DE: 1807 Climate impacts
DE: 1813 Eco-hydrology
DE: 3307 Boundary layer processes
SC: Biogeosciences [B]
MN: 2007 Fall Meeting