Assessing ecological integrity of streams in urbanized forested wetlands of northeastern New Jersey

Streams in urban landscapes are often classified as degraded or impaired when compared to streams in more pristine environments. This classification scheme, however, gives little insight into the patterns and processes that occur within the complex urban mosaic. The objective of this study is to examine the ecological integrity of streams located in urbanized forested wetlands, by quantifying the primary components of ecological integrity and relating changes in ecological integrity to changes in the components (e.g. land use, water quality, etc.) This study was conducted during two sampling seasons in streams within wetlands of differing size and hydrogeomorphic (HGM) classes, in northeastern New Jersey. Benthic macroinvertebrate abundance and family-level richness (i.e. "diversity") were found to be low, compared to non-urban sites. No significant differences in parameters across wetland size and HGM classes were detected. Water quality attributes were slightly, yet not significantly different across wetland size and HGM classes. A subset of streamwater chemical properties (e.g. specific conductance, dissolved oxygen, and pH) explained more than half of the variation in benthic macroinvertebrate abundance and richness during both sampling seasons. A vegetation litter decomposition experiment was conducted within the study streams and did not reveal any significant differences in decomposition rates among streams of differing size and HGM classes. A GIS analysis of landuse/land cover (LU/LC) performed at a local scale and reach scale revealed that LU/LC classes at the local scale were significantly correlated to some instream measures of water quality and benthic macroinvertebrate abundance and richness. The strength of the correlations varied with sampling season. LU/LC categories were analyzed at two different distances from the sampling points (50 and 100 meters), however no significant differences were detected.