A Multitaxonomic Approach to Understanding Local‐ Versus Watershed‐scale Influences on Stream Biota in the Lake Champlain Basin, Vermont, Usa

Abstract

Twenty-one stream reaches in northwestern Vermont were surveyed to assess the relative influence of local-and watershed-scale variables on stream biotic assemblages including fish, aquatic macroinvertebrates and birds. Data were collected during the summers of 2003 and 2004 and included quantitative and qualitative geomorphic and habitat assessments (local-scale) and land-use characterization and modelled annual flow and sediment loading (watershed-scale). Biotic assemblages were surveyed to capture characteristics related to abundance, diversity and composition. Principal components analysis (PCA) was used to generate sets of factors representing unique scenarios of geophysical data derived from various spatial extents within the watershed. These factors were then used as the independent variables in multiple regression models using the biotic data as the dependent variables. Forty significant models were built from the combination of the eight scenarios and 11 dependent variables. Fish assemblage diversity and composition were influenced by a combination of local-scale and watershed-scale variables; however, the qualitative local data were more predictive than the quantitative data. Local-scale data and sediment (model-derived) were important factors in building significant macroinvertebrate models. Bird abundance and species richness were best predicted using local geomorphic characteristics and the qualitative local data. Our results reinforce the concept that whereas both local-and watershed-scale variables affect stream biota, their relative influence depends upon the individual ecology of each taxon. In order to address these issues, comprehensive watershed management, restoration and conservation plans would benefit from assessments at multiple scales and from geomorphological, watershed and multitaxonomic perspectives.

Using a process‐based catchment‐scale model for enhancing field‐based stream assessments and predicting stream fish assemblages

“…The incorporation of catchment modelling into stream assessment protocols may also help to explain additional variation in fish assemblage patterns not fully accounted for by field‐based evaluations, as suggested by Cianfrani et al . () and supported by findings in this study.…”

“…The model was calibrated only for hydrology; sediment and other water quality data were unavailable. Calibration of the model, only with respect to flow, is consistent with other ecological studies using SWAT (Cianfrani et al ., ). Parameters modified for calibration purposes and their original (i.e.…”

“…SWAT was designed to quantify the cumulative impacts of land‐management practices on water, sediment, and nutrient yields in catchments with diverse land cover, land use, soils, and climate (Arnold et al ., ). In spite of its widespread use in modelling the potential effects of climate change and alternative land‐management practices on nutrient and sediment fluxes, catchment hydrology, and stream flow (Douglas‐Mankin et al ., ), SWAT has received relatively little attention as an explicit tool relative to aquatic biota (but see Cianfrani et al ., ).…”

Influence of environmental features at multiple scales and spatial structure on stream fish communities in a tropical agricultural region

“…Although there is a substantial number of studies that address this issue (Lammert & Allan 1999;Diana et al 2006;Johnson et al 2007;Cianfrani et al 2012), including in tropical streams (Cruz et al 2013;Casatti et al 2015;Santos et al 2015), the relative importance of catchment-versus local-scale factors for stream biota has remained elusive (Roth et al 1996;Cianfrani et al 2012). Studies addressing the issue are necessary because the assessment of catchment-stream relationships using a hierarchical classification can aid in conservation, restoration, and management of freshwater systems (Frissell et al 1986;Cianfrani et al 2012;Feld 2013;Dembkowski & Miranda 2014) and provides a more efficient and holistic view of these (Dembkowski & Miranda 2014).…”

“…Studies addressing the issue are necessary because the assessment of catchment-stream relationships using a hierarchical classification can aid in conservation, restoration, and management of freshwater systems (Frissell et al 1986;Cianfrani et al 2012;Feld 2013;Dembkowski & Miranda 2014) and provides a more efficient and holistic view of these (Dembkowski & Miranda 2014).…”