Table of Contents
ISRN Ecology
Volume 2011, Article ID 571749, 11 pages
http://dx.doi.org/10.5402/2011/571749
Research Article

Partial Least Square Analyses of Landscape and Surface Water Biota Associations in the Savannah River Basin

US EPA, ORD, Landscape Ecology Branch, 944 E. Harmon Ave, Las Vegas, NV 89119, USA

Received 13 January 2011; Accepted 17 March 2011

Academic Editors: I. Izaguirre and M. van Noordwijk

Copyright © 2011 Maliha S. Nash and Deborah J. Chaloud. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Ecologists are often faced with problem of small sample size, correlated and large number of predictors, and high noise-to-signal relationships. This necessitates excluding important variables from the model when applying standard multiple or multivariate regression analyses. In this paper, we present the results of applying PLS to explore relationships among biotic indicators of surface water quality and landscape conditions accounting for the above problems. Available field sampling and remotely sensed data sets for the Savannah Basin are used. We were able to develop models and compare results for the whole basin and for each ecoregion (Blue Ridge, Piedmont, and Coastal Plain) in spite of the data constraints. The amount of variability in surface water biota explained by each model reflects the scale, spatial location, and the composition of contributing landscape metrics. The landscape-biota model developed for the whole basin using PLS explains 43% and 80% of the variation in water biota and landscape data sets, respectively. Models developed for each of the three ecoregions indicate dominance of landscape variables which reflect the geophysical characteristics of that ecoregion.