Land-Use Effects on Catchment- and Patch-Scale Habitat and Macroinvertebrate Responses in the Adirondack Uplands
Thomas Woodcock, Timothy Mihuc, Edwin Romanowicz, and Eileen Allen
Abstract.—Catchment characteristics and land-use practices can affect stream habitats at a variety of spatial scales. A suite of variables describing catchment geomorphology (area, circularity, slope, elevation, soil depth, surficial geology), surface water hydrology (drainage density, water velocity, Froude number), and patch (channel) habitat (slope, bank-full width, water depth, substrate particle size, stored and transported organic matter, transported inorganic sediment) were determined using a geographic information systems and field surveys in 19 upland Adirondack catchments (New York, USA) with differing land uses (New York Forest Preserve [Preserve] versus logging). Surber samples of macroinvertebrate assemblages and stored organic matter were collected in July 2003. Catchment geomorphology was similar between land-use types. However, Preserve streams tended to have deeper and wider channels, despite steeper channel slopes, while logged streams had more stored organic matter and finer substrate particles. We collected 177 macroinvertebrate taxa from the streams, and taxa richness was significantly reduced in logged catchments (p = 0.006). Twenty-seven taxa occurred more frequently in Preserve sites, while nine taxa occurred more commonly in logged streams (chi-square, p < 0.10). Distributions of these taxa were related to water quantity, channel geomorphology, and particle size at the patch scale and circularity, drainage patterns, and sediment load at the reach scale. The presence and absence of invertebrate taxa across the Adirondack landscape was controlled mainly by a combination of catchment-scale geomorphic and anthropogenic (forest management) factors. Patch-scale factors, although influenced by their catchments, had less effect on distributions.