A novel approach to assess the impact of landuse activity on chemical and biological parameters in river catchments

作者：Mason Johnson, Paul S. Giller, John O’Halloran, Kieran O’Gorman, Maeve Gallagher · 发表于：Freshwater Biology · 年份：2005 · DOI：10.1111/j.1365-2427.2005.01389.x · 被引用次数：19 · 研究领域：Freshwater macroinvertebrate diversity and ecology、Soil and Water Nutrient Dynamics、Fish Ecology and Management Studies

Summary 1. Natural variation in environmental parameters, as well as practical constraints in study design and sampling methodology, often pose difficulties in treating impact assessments in river catchments as controlled field experiments. It is frequently impossible to develop robust relationships between reference and test stations prior to the onset of an impact and the range of statistical tools which can be adopted in data analysis to detect a change or disturbance is limited. 2. In an attempt to overcome these problems we introduce a novel disturbance index to assess the impact of landuse activities on river systems. The index identifies differences in hydrochemical parameters and macroinvertebrate community metrics between reference and test stations (at a set level of significance). This approach allows for objective assessment of the occurrence and direction of change as well as the duration of an impact. The disturbance index can be applied at different scales – for a single stream, a catchment or a region. 3. In this paper we describe the derivation of the index and illustrate its utility through worked examples. We use the index to assess impact of clearfelling on hydrochemical parameters such as hydrogen ion concentration, total hardness, suspended solids, conductivity and nitrate concentration as well as on macroinvertebrate parameters including abundance, richness, reciprocal of Simpson's diversity index, evenness, Ephemeroptera/Plecoptera/Trichoptera (EPT) ri...