Studies on the characteristics of sedimentation in mangrove forest (I) : On the grain size distribution of surface deposit in the mangrove forest on the Kesaji River (Department of Forestry)

摘要

In order to investigate grain size distributions of surface deposit in the mangrove forest, the sampling was performed in the mangrove forest on the Kesaji River in Okinawa island. From the results of grain-size analysis the followings were recognized. 1. The forms of grain size distribution curves of the samples from the plots in the mangrove forest and near the stream can be distinguished. 2. The samples form the plots in the mangrove forest contain silt, clay and colloid more than sixty parcentage. The parcentage of them increases with distance from the forest edge. 3. In the river bed, there is not apparent difference in the forms of grain size distribution curves among the plot No.1 of course I and course II. The intense dependences between the distinguishable differences inside and outside of the forest, and the density and the formation of the mangrove forest are conjectured.