Stream macroinvertebrate communities in urbanizing watersheds in Maryland, USA

Abstract

The conversion of agricultural landscapes into residential developments is a prominent form of land use change in Maryland. Macroinvertebrates were sampled in Maryland headwater streams, and used to test for differences in diversity and abundance between agricultural and developed sites. Macroinvertebrate richness was highest in the agricultural streams, possibly due to a negative relationship between richness and impervious surface cover. The nature of farming operations and their proximity to the stream may contribute to increased richness values.

In Chapter 2, I compare macroinvertebrate communities collected with single-habitat and multi-habitat sampling methods. Communities were compared using IBI scores, and the community variables comprising these IBI's. Several community variables differed between methods, however the IBI scores calculated using the two methods were strongly correlated. Single-habitat samples had a slightly stronger relationship with development, indicating that they may be better for monitoring important focal sites.