Geoscience Reference
In-Depth Information
Chapter 4
On the Relationship Between Stream
Biotic Diversity and Exurbanization
in the Northeastern USA
Scott Goetz and Gregory J. Fiske
Abstract Stream macroinvertebrate diversity is a commonly used indicator of
aquatic health, reflecting overall ecological integrity within a watershed. Our
study made use of two metrics of stream biota, the Hilsenhoff Biotic Index (HBI)
and the diversity of
Ephemeroptera
,
Plecoptera
, and
Tricoptera
(nEPT) species,
to develop statistical models relating land cover information within watersheds
to these stream biotic health indicators. The study area in southern New England
included over 100 small streams, which make up a substantial portion of the
region's largest catchments. General additive models (GAM) and step-wise
multiple linear regression (MLR) models were used to explore the relationship
between the land cover and the biotic indicators. Although the GAMs explained
a greater amount of the variation in the stream biota metrics, the MLR models were
also consistently reliable predictors of nEPT and HBI. This research indicates land
cover can be used as a robust predictor of stream biological indicators of small
catchments (HUC12) in the region, and help to target streams for restoration or
protection.
Keywords Aquatic • Biodiversity • Habitat • Impervious • Land cover • Land use
• Remote sensing • Species richness • Water quality • Stream • Watershed
4.1
Introduction
The links between land cover and water quality, including stream health, have long
been known but not until recently have analyses over large areas been conducted
(Mitsch et al.
2001
; Nilsson et al.
2003
; Carlisle and Meador
2007
). This is partly
a result of wider availability of land cover information from regional to national
