Ecosystem integrity in Adirondack upland headwater catchments: scale related patterns in stream biota.

T.B. Mihuc¹, E.A. Romanowicz¹, T. Woodcock¹, E Allen¹, J.R. Mihuc², C. Cirmo³, R. Fuller¹, D. Franzi¹, C. Evans², and J. Allen².¹Lake Champlain Research Institute and Center for Earth and Environmental Science, SUNY Plattsburgh, Plattsburgh NY 12901, ²Paul Smiths College, Rts 86 and 30, Paul Smiths, NY 12970, ³Dept of Geology, SUNY Cortland, Cortland, NY

Catchment scale characteristics and land use practices were used to define and assess ecosystem integrity in a series of Adirondack upland headwater catchments. Land use categories included logged catchments and reference systems located in the New York State Forest Preserve. A suite of variables describing catchment geomorphology, surficial geology, water chemistry, surface water hydrology, and channel habitat were determined at two different scales of observation, the entire catchment and a 250 reach within each catchment . Physical-chemical variables were compared to biotic responses among stream biota and upland plant communities. Over 175 macroinvertebrate taxa were recorded in the streams with overall taxa richness reduced in managed watersheds (p=0.006). 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 hydrology variables, forest community composition and riparian plant communities also showed differences between managed and Preserve catchments. Multivariate comparison of these variable sets suggests that catchment scale variables are more important in defining stream invertebrate community patterns in Adirondack Upland systems. Patterns in water chemistry and physical variables also suggest that catchment scale variables are the drivers for physical-chemical responses in these small (2-8 km²) systems.