Effects of landslides on vegetation with special reference to significance of studies from a geo-historical viewpoint

Abstract

This report reviews the advances in research regarding the relationship between landslides and vegetation, and offers suggestions for future studies to clarify the long-term effects of landslides on vegetation. A landslide area consists of a sliding scar and a displaced mass. Micro-landforms such as small scars, mounds, depressions, and block fields are formed within the displaced mass and behind the main sliding scar. The spatiotemporal distribution of landslide areas is heterogeneous, being affected by climatic conditions, bedrock, and the initial landforms. Because the landforms are modified, and new edaphic, microclimatic, and hydrological conditions are created by landslides, various types of vegetation occur in a landslide area. The trajectories of vegetation succession depend on age, elevation, slope aspect, and the bedrock of the landslide area, and are also affected by slope surface stability, soil texture, and the existence of biological legacies, which are spatially heterogeneous within a landslide area. Examining the long-term effects of landslides on the development of vegetation patterns and endemic flora in mountainous areas is important. These long-term effects should be clarified by making a comparative study of landslides of different ages. Landslides, as well as glacial and periglacial processes, appear to play a major role in forming the alpine landscape of Japan, and ridgetop depressions can provide good opportunities to investigate the long-term effects of landslides on alpine vegetation.