VEGETATION PATTERNS IN RELATION TO MICROSCALE LANDFORMS IN HILLY LAND REGIONS

Spatial structures of landforms as constants affecting vegetation patterns are discussed based on analyses of hilly land regions, mostly in the vicinity of Sendai, northeast Japan. The lower part of a hillslope is characterized by relatively active processes of soil erosion, landslides and slope failure. It supports a plant community different from that on the upper part of the hillslope. These two parts are termed the lower hillslope and the upper hillslope, respectively. The upper hillslope consists of valley heads with no stream water nor stream channels. Since a valley head is comprised of several micro-scale landform units, an upper hillslope can be subdivided into these landform units. Plant communities vary in their species compositions and structures as well as in some other ecological characteristics paralleling changes in their respective micro-scale landform units. However, the variations in species composition within upper hillslopes are not as extreme as those between the upper and lower hillslopes.