Abstract
We investigated the effects of bamboo (Phyllostachys edulis) forest expansion on the soil physical properties, such as hydraulic conductivity, water retention, and water repellency. We also examined the pathways of water movement in soil using a dye tracer experiment. Moreover, we surveyed the effects of the expansion on snow accumulation and melt. Soil physical characteristics in the bamboo forest expansion and deciduous plots were quite different with respect to the soil surface; the bamboo forest has much more root mass and lower dry bulk density. As root mass increases, volumetric water content at the same matric potential decreases. Therefore, it can be concluded that water retention is reduced as the bamboo forest expands. Results of the dye tracer experiment indicate that water moves through roots and cracks, and the dye was observed in the soil from the surface to a depth of 30 cm. Moreover, soil water repellency was observed in the bamboo forest expansion and this contributed to the concentration of rainwater pathways. Snow period and snow depth in a bamboo expansion plot were less than those of deciduous plot by 14%, indicating that bamboo forest expansion has a significant effect on water resources in snowy areas.
