2016 Volume 98 Issue 5 Pages 193-198
We measured surface soil (fine soil, gravel, and litter) movement in three types of plantation about 40 years old, namely Japanese cypress (Chamaecyparis obtusa), Japanese cedar (Cryptomeria japonica), and Japanese red pine (Pinus densiflora). All of the stands were growing under the same conditions on a steep slope and differed only in terms of the planted species. We also clarified the differences in surface soil movement among the planted species. Movement of fine soil, gravel, and litter per 1 mm precipitation (i.e. the transport rate) was higher in the C. obtusa stand than in the others. The floors of the C. japonica and P. densiflora stands were almost covered with either litter or undergrowth all year around, whereas on the floor of the C. obtusa stand the cover of undergrowth and litter was poorer. A higher floor cover percentage led to a lower rate of transport of fine soil. Consequently, the C. obtusa stand was characterized by easily lost undergrowth and litter, which in turn influenced surface soil movement. Because of the low litter cover, in C. obtusa stands with poor vegetation cover, control of light conditions by tree thinning and maintenance of undergrowth are needed to minimize surface soil movement.
