Royer T V, Robinson C T, Minshall G W
Department of Biological Sciences, Idaho State University, Pocatello 83209-8007, USA.
Environ Manage. 2001 Apr;27(4):627-36. doi: 10.1007/s002670010175.
Theoretical constructs, such as the river continuum concept, predict that the composition of benthic fauna in rivers will be different from that of headwater streams. There exists a need to modify, for use on larger rivers, the bioassessment techniques commonly used on small streams. Using aquatic macroinvertebrates and the "reference condition" approach, we developed and tested a multimetric index for use on the rivers of Idaho. Reference sites were selected to represent the best current conditions (i.e., least impacted) among Idaho rivers. The index performed well in distinguishing reference sites from sites displaying some form of anthropogenic impairment. Individual metrics used in the index included: number of EPT taxa, total number of taxa, percent dominant taxon, percent Elmidae, and percent predators. The index we developed for Idaho rivers was essentially a modification of a framework designed for small streams, suggesting that techniques, including data analysis, currently used for streams can be adapted for use on larger rivers. Adapting these methods for use in rivers is primarily a matter of (1) selecting metrics relevant to the rivers of interest; (2) expanding the field sampling to encompass the greater habitat area and, potentially, heterogeneity of rivers; and (3) selecting an appropriate form of data analysis. The approach we describe here should be applicable to geographic regions other than Idaho.
理论构建，如河流连续体概念，预测河流中底栖动物的组成将与源头溪流不同。有必要对通常用于小溪流的生物评估技术进行修改，以便用于更大的河流。我们利用水生大型无脊椎动物和“参考条件”方法，开发并测试了一种用于爱达荷州河流的多指标指数。参考站点被选为代表爱达荷州河流中当前最佳状况（即受影响最小）的站点。该指数在区分参考站点和显示某种形式人为损害的站点方面表现良好。该指数中使用的个体指标包括：EPT分类单元数量、分类单元总数、优势分类单元百分比、埃尔米idae百分比和捕食者百分比。我们为爱达荷州河流开发的指数本质上是对为小溪流设计的框架的修改，这表明目前用于溪流的技术，包括数据分析，可以适用于更大的河流。将这些方法应用于河流主要涉及以下几点：（1）选择与感兴趣的河流相关的指标；（2）扩大实地采样范围，以涵盖河流更大的栖息地面积以及潜在的异质性；（3）选择合适的数据分析形式。我们在此描述的方法应适用于爱达荷州以外的地理区域。
