Agricultural disturbance response models for invertebrate and algal metrics from streams at two spatial scales within the U.S.
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- 作者：Ian R. Waite (1)
- 关键词：Scale ; Stream bioassessment ; Predictive models ; Riparian ; Invertebrates ; Algae
- 刊名：Hydrobiologia
- 出版年：2014
- 出版时间：March 2014
- 年：2014
- 卷：726
- 期：1
- 页码：285-303
- 全文大小：477 KB
- 作者单位：Ian R. Waite (1)
1. Oregon Water Science Center, U.S. Geological Survey, 2130 SW 5th Ave, Portland, OR, 97211, USA - ISSN：1573-5117
文摘
As part of the USGS study of nutrient enrichment of streams in agricultural regions throughout the United States, about 30 sites within each of eight study areas were selected to capture a gradient of nutrient conditions. The objective was to develop watershed disturbance predictive models for macroinvertebrate and algal metrics at national and three regional landscape scales to obtain a better understanding of important explanatory variables. Explanatory variables in models were generated from landscape data, habitat, and chemistry. Instream nutrient concentration and variables assessing the amount of disturbance to the riparian zone (e.g., percent row crops or percent agriculture) were selected as most important explanatory variable in almost all boosted regression tree models regardless of landscape scale or assemblage. Frequently, TN and TP concentration and riparian agricultural land use variables showed a threshold type response at relatively low values to biotic metrics modeled. Some measure of habitat condition was also commonly selected in the final invertebrate models, though the variable(s) varied across regions. Results suggest national models tended to account for more general landscape/climate differences, while regional models incorporated both broad landscape scale and more specific local-scale variables.