Patterns of sediment production and outflow required for creation and maintenance of stream habitat structure

在一组不同历史的森林砍伐和泥石流的山区溪流的栖息地结构和底栖无脊椎动物群落结构的产沙量和流出量的关系进行了研究。小生境多样性在最后一次森林砍伐和/或泥石流后的特定时期表现出最大值。底质上苔藓垫的覆盖度和裸露石块与部分掩埋石块的比例可以通过产沙量和河床宽度的综合因素来解释。此外，通过对水库尾水河段的现场观测和室内松花粉示踪试验，发现桑迪结构的发育提高了悬浮颗粒有机物（SPOM）的截留效率。

Relations of habitat structure and benthic invertebrate community structure to the amount of sediment production and outflow were studied in a set of mountain streams different in histories of deforestation and debris flow. Microhabitat diversity showed the maximum values in a specific period after the last deforestation and/or the last debris flow. Coverage of moss mat on substrates and ratio of exposed stones to partially buried stones could be explained by combined factors of sediment production and the riverbed width. Furthermore, we found that development of sandy bar structure enhanced the trapping efficiency of suspended particulate organic matter (SPOM) by the field observation in the tailwater reaches of dam reservoir and by the laboratory experiment using pine pollens as an SPOM tracer.