Watershed Land Use and Local Habitat: Implications for Habitat Assessment

Abstract

Our understanding of anthropogenic stressor effects on wetland biota and ecosystem processes would benefit from better defined relationships between landscape and local stressors. We assessed the connection between watershed land use and local habitat and local disturbance in Great Lakes coastal ecosystems across a full range of anthropogenic stress. In addition, we identified dominant structuring variables, described redundancy, and assessed the relative influence of local versus watershed scale features on local habitat quality with on-site assessments conducted at 143 sample sites. Associations between habitat variables and watershed stressors were found, but only a small proportion of variation was explained. Overall, watershed agriculture was a stronger predictor of local habitat variables than was development. Variance partitioning revealed that disturbance and land use accounted for more variance in habitat than spatial factors or wetland type. This indicates that local and watershed-scale assessments are discrete approaches that document stress at different hierarchical scales and an assumed direct connection between watershed stress and local habitat and disturbance is an over-simplification. Therefore, assessments of stress should include both watershed scale and on-site habitat assessments. Furthermore, these results indicate that local scale mitigation/restoration could minimize negative impacts of changing land use.