Effects of forest floor cover and horizontal step works made from thin logs on the surface soil movement in sugi (Cryptomeria japonica (L.f.) D. Don) and hinoki (Chamaecyparis obtusa (Siebold et Zucc.) Endl.) plantations

Abstract

Effects of forest floor cover and horizontal step works made from thin logs on the surface soil movement were investigated based on sediment transport rates of the forest floors in three stands of sugi and hinoki plantations for 3 years. These plantations had different surface geologies. Exponential models based on the floor cover percentages (FCP) and the sediment transport rates that approximated separately for each stand (with/without horizontal step works) showed that sediment transport rates decreased as the FCP increased, regardless of the stand and the absence/presence of the horizontal step works. Sediment transport rates of the forest floors were lower in the presence of horizontal step works, and the differences between conditions in the absence or presence of horizontal step works increased as the FCP decreased.