PARENT SESSION
Contributed Oral Session 43: Landscape Ecology
Tuesday, August 9, 8:00 AM - 11:30 AM, Meeting Room 518 A, Level 5, Palais des congrès de Montréal
Ecosystem integrity in Adirondack upland headwater catchments.
Mihuc, Timothy *,1, Woodcock, Thomas 1, Romanowicz, Edwin 1, Mihuc, Janet 2, Allen, Eileen1, 1 Plattsburgh State University of New York, Plattsburgh, New York, USA2 Paul Smith's College, Paul Smith's, New York, USA
ABSTRACT- Catchment scale characteristics and land use practices were used to define and assess ecosystem integrity in 18 Adirondack upland headwater catchments, half of which were managed for timber harvest and half of which were in the New York State Forest Preserve. A suite of variables describing catchment geomorphology (area, circularity, slope, elevation, aspect, soil depth, surficial geology), water chemistry, surface water hydrology (drainage density, baseflow discharge, flashiness, groundwater influx, water velocity), and channel habitat (slope, width, depth, substrate particle size, stored and transported organic matter, transported sediment) were determined. These data were compared to biotic data (stream biota and upland plant communities). Watershed geomorphology was similar between land use types. However, Forest Preserve streams tended to have deeper and wider channels (despite steeper channel slopes), while streams in logged watersheds had more stored organic matter and finer substrate. Over 175 macroinvertebrate taxa were recorded in the streams, and taxa richness was significantly reduced in managed watersheds (p=0.006). 27 taxa showed a bias toward Preserve sites, and 9 were more common in managed streams (chi-square, p<0.10). Distributions of these taxa were related to channel geomorphology and particle size at the patch scale, and watershed circularity, ground and surface water drainage patterns, and inorganic sediment load at the watershed scale. Invertebrate distributions were affected both by land use patterns and watershed-scale geomorphologic variables. Fish (Brook trout) had higher biomass and density in managed sites. Surface water chemistry, selected hydrologic variables, forest community composition and riparian plant communities also showed differences between managed and Preserve catchments. Multivariate comparison of these variable sets has allowed us to develop a preliminary definition of ecosystem integrity in these systems.
Key words: ecosystem integrity, headwater, catchment scale, adirondack uplands