Effects of fluvial processes and human activities on stream macro-invertebrates  

作　　者：Xue-hua DUAN Zhao-Yin WANG Meng-zhen XU 

机构地区：[1]State Key Laboratory of Hydroscience and Engineering, Tsinghua University, Beijing 100084, China [2]Doctoral candidate, State Key Laboratory of Hydroscience and Engineering, Tsinghua University, Beijing 100084, China

出　　处：《International Journal of Sediment Research》2011年第4期416-430,共15页国际泥沙研究（英文版）

基　　金：supposed by the Ministry of Water Resources of China(Grant No.200901078);Tsinghua University(Grant No.2009THZ02234);the Natural Science Foundation of Jiangsu Province of China (Grant No.BK2010168);the Environmental Monitoring Center of Jiangsu Province of China(Grant No.1002)

摘　　要：Benthic macro-invertebrates are vital components of river ecosystems. The effects of fluvial processes and human activities on the distribution of macro-invertebrates were studied through field investigations and experiment. Sixty-one sampling sites on 31 rivers in China were selected to investigate the structures of macro-invertebrate assemblages. The rivers, according to their fluvial conditions, are classified as streams with a stable channel bed, degrading channel bed, aggrading channel bed, and intensive bed load motion. The structures of macro-invertebrate fauna for the four types of rivers are very different. Stable rivers have a large number of individuals, abundant fauna, and high biodiversity; while the density and taxa richness for degrading rivers are small, and those for aggrading rivers are much less; whereas the ecology of rivers with intensive bed load motion are the worst. This paper proposes that streambed stability is the primary influential factor shaping the structure of benthic macro-invertebrate communities. Organic pollution can obviously result in the decrease of biodiversity, in the simplification of macro-invertebrate structures, and in the distortion of functional feeding group composition. In a river with high total nitrogen content, the relative abundance of collector-gatherers is high, and that of collector-filterers, scrapers, shredders, and predators are low. Scrapers, shredders, and predators disappear in severely polluted rivers. The isolation of aquatic habitat results in a distinct decrease of individual numbers and taxa richness. This result demonstrates that the connectivity of aquatic habitat significantly affects macro-invertebrate assemblages. A practical method to calculate a Habitat Suitability Index （HSI） is proposed, integrating the effects of the primary physical （including biotic and abiotic） and chemical factors. The biodiversity and taxa richness increase non-linearly with HSI.Benthic macro-invertebrates are vital components of river ecosystems. The effects of fluvial processes and human activities on the distribution of macro-invertebrates were studied through field investigations and experiment. Sixty-one sampling sites on 31 rivers in China were selected to investigate the structures of macro-invertebrate assemblages. The rivers, according to their fluvial conditions, are classified as streams with a stable channel bed, degrading channel bed, aggrading channel bed, and intensive bed load motion. The structures of macro-invertebrate fauna for the four types of rivers are very different. Stable rivers have a large number of individuals, abundant fauna, and high biodiversity; while the density and taxa richness for degrading rivers are small, and those for aggrading rivers are much less; whereas the ecology of rivers with intensive bed load motion are the worst. This paper proposes that streambed stability is the primary influential factor shaping the structure of benthic macro-invertebrate communities. Organic pollution can obviously result in the decrease of biodiversity, in the simplification of macro-invertebrate structures, and in the distortion of functional feeding group composition. In a river with high total nitrogen content, the relative abundance of collector-gatherers is high, and that of collector-filterers, scrapers, shredders, and predators are low. Scrapers, shredders, and predators disappear in severely polluted rivers. The isolation of aquatic habitat results in a distinct decrease of individual numbers and taxa richness. This result demonstrates that the connectivity of aquatic habitat significantly affects macro-invertebrate assemblages. A practical method to calculate a Habitat Suitability Index （HSI） is proposed, integrating the effects of the primary physical （including biotic and abiotic） and chemical factors. The biodiversity and taxa richness increase non-linearly with HSI.

关 键 词：Macro-invertebrate Streambed stability SUBSTRATUM Isolation Habitat suitability Water pollution 

分 类 号：X171.5[环境科学与工程—环境科学] TV147[水利工程—水力学及河流动力学]