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可观，而从凋落叶分解中产生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滤实验和野外测量，阐明在所调查河流河岸区占主导地位的常绿树种凋落叶的淋滤特征，并研究淋滤液对山溪水离子组成的影响。由此推断，并非所有在样地沉积的凋落物都在样地被分解，因为大部分从河岸林输入到湿地系统的凋落物在分解的同时被运送到下游，而与凋落物分解相关的DO饱和度的显著下降应该发生在满足促进凋落物保留条件的样地，如河道配置、河岸带面积、河流边缘的水文和基质特征，河流的排放特征，生物条件，如碎纸机密度，等等。泉水中岩石风化作用是离子的主要来源，水塘、水塘和边塘中同时存在多源离子负荷，凋落叶是溪流中K+、Mg2+和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.