Analysis of mass transfer processes derived from leaf litter among sabo r eachesin mountain streams.

据估计，外来物质的数量相当大，从落叶分解而来的物质被认为对溪流水质有重要影响。本研究的目的是通过室内淋洗实验和野外测量，弄清所调查河流河岸带主要常绿树种凋落物的淋溶特征，并研究渗滤液对山溪水离子组成的影响。由此推断，并非所有样地的凋落物都被分解，因为从河岸森林输入到热带系统的大部分凋落物在分解时被运往下游，与凋落物分解相关的DO饱和度的显著下降应发生在满足促进凋落物保留的条件的地点，如河道形状、河岸带面积、河缘的水文和底质特征、溪流的排放特征和生物条件，如碎纸机密度等。春季离子的主要来源是岩石风化，冲沟、水池和侧池同时存在多种来源的离子负荷，枯枝落叶层是溪水K+、Mg2+、Ca2+的主要来源之一。

The amount of allochthonous material is estimated to be considerable, and substances derived from the decomposition of leaf litter are thought to have an important impact on stream water quality. The purpose of the present study is to clarify the leaching characteristics of leaf litter of the evergreen species that are dominant in the riparian zone of the investigated stream and to examine the influence of leachates on mountain stream water ionic composition by laboratory leaching experiments and field measurements. It was infered that not all of the litter deposited at a sample site was decomposed in the site, as most litter input from riparian forests into lotic systems is transported downstream while being decomposed and that the marked decrease in the DO saturations in relation to the litter decomposition should occur in a site satisfing the conditions for promoting litter retention such channel configuration, the area of the riparian zone, the hydrological and substrate characteristics along the stream margin, the discharge characteristics of the stream, biological conditions such as shredder density, and so on. It was also indicated that the primarily source of ions is rock weathering in the spring and simultaneous ion loading from multiple sources occurs in the riffle, pool and side-pool and that leaf litter is one of the primary sources of K+, Mg2+and Ca2+in the stream water.