Research on Leaf Decomposition Rate in Tamagawa River Basin

Abstract

The decomposition of litter is an important function in the regulating service of the river ecosystem. The decomposition of litter can not only provide energy and material for the ecosystem, but also evaluate the health of the ecosystem. Fallen leaves are the most common litter in the riparian zone. There are three main stages in the decomposition of leaves in rivers. In these three stages, there are many factors that affect the rate of decomposition of leaves. These factors are divided into three categories: the difference in the physical and chemical properties of the litter itself, the difference between the biological and non-biological characteristics in the river, and the feeding activity of the shredder. However, the previous scholars’ studies on leaf decomposition mostly focused on soil ecosystems, and there were few studies on leaf decomposition in aquatic ecosystems. And no one has studied the relationship between blade surface hardness and thickness and blade decomposition rate. In addition, previous studies were conducted at fixed locations in the river, and very few studies have been conducted on different areas of the same river. In this study, three sites in the upper, middle and lower reaches of the tamagawa river were selected for leaf decomposition experiments. And use the newly designed penetrometer and micrometer to measure the surface hardness and thickness of the leaves. After 25 days of decomposition experiments, the final results showed that the lower the hardness and thickness of the leaves, the higher the decomposition rate. But when the blade hardness and thickness are similar, the characteristics of the blade surface will also affect the decomposition speed of the blade. An `d human activities will affect the function of leaf decomposition in the river ecosystem.