HR: 0800h
AN: C21A-1069    [Abstracts]
TI: Quantifying the effects of vegetation on a montane snowpack, Valles Caldera National Preserve, NM
AU: * Musselman, K
EM: keith@hwr.arizona.edu
AF: Hydrology and Water Resources and SAHRA, 1133 E. James E Rogers Way University of Arizona, Tucson, AZ 85721
AU: Brooks, P D
EM: brooks@hwr.arizona.edu
AF: Hydrology and Water Resources and SAHRA, 1133 E. James E Rogers Way University of Arizona, Tucson, AZ 85721
AU: Molotch, N P
EM: molotch@cires.colorado.edu
AF: CIRES University of Colorado at Boulder, 216 UCB Room 318, Boulder, CO 80309
AB: We evaluated the effects of vegetation on snowpack mass and energy exchange in a seasonally snow covered sub-alpine montane environment, Valles Caldera National Preserve, New Mexico, USA. Detailed field observations and ultra-sonic snow depth sensors indicated forest vegetation affected snowcover in three ways; canopy interception and sloughing, enhanced snowpack metamorphism, and shading of direct solar radiation. Manual observations of snowpack properties (i.e. snow density, depth, temperature, crystal type, and grain size), at 0.5 meter intervals from an individual spruce tree, showed that on south aspects density and grain size peak at the canopy fringe while SWE and depth peak in the open beyond the canopy fringe; on north aspects only grain size peaks at the canopy fringe while SWE, depth, and density peak in the open. Snow surveys around 16 additional trees at max accumulation indicated that while snow depth increased logarithmically away from trees, SWE increased linearly outward from trunks. In general, the order of mean SWE was: north side of trees open (30 ±10 cm), south side of trees open (27 ±10 cm), north side of trees canopy fringe (26 ±10 cm), south side of trees canopy fringe (20 ±10 cm), and north and south sides underneath tree canopies (10 ±6 cm). Catchment-wide snow surveys indicate that elevation, aspect, and proximity to vegetation explained 25, 38 and 40% of snow depth variability, respectively. These data provide new insight into the effects of vegetation on snowpack accumulation, metamorphism, and melt.
DE: 0736 Snow (1827, 1863)
DE: 0740 Snowmelt
SC: Cryosphere [C]
MN: Fall Meeting 2005