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

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.

Relative Importance of Water‐Quality Stressors in Predicting Fish Community Responses in Midwestern Streams

“…PLS analysis (Wold ) is a multivariate technique that combines features from principal component analysis and multiple linear regression. PLS analysis has been used to assess the relative importance of land use and land cover metrics in predicting fish and invertebrate community responses (Nash and Chaloud ).…”

“…PLS analysis extracts linear combinations, or factors (similar to components), in order to develop a model that optimally explains response variation. The number of factors extracted was determined using the predicted residual sum of squares (PRESS) and the model with the minimum PRESS was chosen (Nash and Chaloud ). The minimum value of PRESS represents the model with the best predictive ability (Abdi ).…”

Linking mutagenic activity to micropollutant concentrations in wastewater samples by partial least square regression and subsequent identification of variables

“…PLS has been demonstrated to provide meaningful correlation of chemical fingerprints of exhaust particle extracts and mutagenicity, but also of biotic indicators of surface water quality and landscape conditions (Eide et al, 2002;Nash and Chaloud, 2011).…”

Evaluating Flood Exposure for Properties in Urban Areas Using a Multivariate Modelling Technique

“…PLS was originally developed as a technique in econometrics, but today, it is primarily used as a tool for chemometrics. Occasionally, PLS is used for environmental studies in order to investigate patterns among variables in environmental studies [25,26]. The software Unscrambler ® version 10.3 (CAMO Software AS, Oslo, Norway) was used for this analysis [27].…”