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Comparison of stream invertebrate response models for bioassessment metric

Journal of the American Water Resources Association

By:
, , , , , , and
DOI: 10.1111/j.1752-1688.2011.00632.x

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Abstract

We aggregated invertebrate data from various sources to assemble data for modeling in two ecoregions in Oregon and one in California. Our goal was to compare the performance of models developed using multiple linear regression (MLR) techniques with models developed using three relatively new techniques: classification and regression trees (CART), random forest (RF), and boosted regression trees (BRT). We used tolerance of taxa based on richness (RICHTOL) and ratio of observed to expected taxa (O/E) as response variables and land use/land cover as explanatory variables. Responses were generally linear; therefore, there was little improvement to the MLR models when compared to models using CART and RF. In general, the four modeling techniques (MLR, CART, RF, and BRT) consistently selected the same primary explanatory variables for each region. However, results from the BRT models showed significant improvement over the MLR models for each region; increases in R2 from 0.09 to 0.20. The O/E metric that was derived from models specifically calibrated for Oregon consistently had lower R2 values than RICHTOL for the two regions tested. Modeled O/E R2 values were between 0.06 and 0.10 lower for each of the four modeling methods applied in the Willamette Valley and were between 0.19 and 0.36 points lower for the Blue Mountains. As a result, BRT models may indeed represent a good alternative to MLR for modeling species distribution relative to environmental variables.

Geospatial Extents

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Comparison of stream invertebrate response models for bioassessment metric
Series title:
Journal of the American Water Resources Association
DOI:
10.1111/j.1752-1688.2011.00632.x
Volume
48
Issue:
3
Year Published:
2012
Language:
English
Publisher:
American Water Resources Association
Publisher location:
Herndon, VA
Contributing office(s):
Oregon Water Science Center
Description:
14 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Journal of the American Water Resources Association
First page:
570
Last page:
583
Country:
United States
State:
California;Oregon
Other Geospatial:
Blue Mountains;Willamette Valley