HR: 0800h
AN: C21B-0447    [Abstracts]
TI: Forest Cover and Topographic Influences on Snow Distribution in a Mixed Hardwood-Conifer Forest of the Northeastern U.S.
AU: * Larsen, T A
EM: tlarsen@uvm.edu
AF: Department of Geology, University of Vermont, Burlington, VT 05405, United States
AU: Wemple, B
EM: bwemple@uvm.edu
AF: Department of Geography, University of Vermont, Burlington, VT 05405, United States
AU: Keeton, W
EM: wkeeton@uvm.edu
AF: Rubenstein School of Environment and Natural Resources, University of Vermont, Burlington, VT 05405, United States
AB: Forested landscapes of the northeastern U.S. face increasing pressure from development and recreational uses. Changes in forest structure and the distribution of canopy openings may have measurable impacts on hydrology, particularly in high elevation terrain where gradients in atmospheric inputs are great. Here, we report findings of a pilot study conducted in spring 2007 to examine the effects of forest stand and canopy structure, canopy openings and topography on snow distribution. Our sampling sites are located within on-going studies of canopy development following silvicultural treatments and forest clearings from recreational development (i.e. alpine skiing) in the mixed hardwood-conifer forests of northwestern Vermont. Our findings indicate that snow water equivalent (SWE) was significantly related to key forest metrics including conifer abundance and mean diameter at breast height (dbh). SWE exhibited strong elevational trends over three sampling dates and was more spatially variable on south-facing slopes than on all other aspects. Comparisons between forested and open sampling sites showed no differences in SWE for early (DOY 60 and 68) sampling dates, but differences were significant for later sampling dates (DOY 71 and 82) at high elevation sites. Along ski trail clearings, surveys using ground-penetrating (GPR) radar showed significant differences in SWE for trails covered with man- made snow, relative to those covered with natural snow. Collectively, our findings suggest that (1) mixed forests of the Northeast have limited ability to influence snowpacks through interception when some conifer component exists in the stand, (2) these forests have detectable effects on snowmelt dynamics relative to clearings, (3) topography exerts strong controls on snow distribution, and (4) man-made snow on recreational ski trails introduces an additional layer of variability in snowpack distribution. We speculate on the hydrologic consequences of these findings using a simple, GIS-based model incorporating snow distributing and routing.
DE: 0736 Snow (1827, 1863)
SC: Cryosphere [C]
MN: 2007 Fall Meeting