Forests as environment for mankind as well as environment of forests per se are increasingly important to the progress of urbanization and regional development. The objective of these proceedings is to integrate many fields of related sciences to a concept of environmental forest science, which will be developing and promising in the 21st century. The book consists of 69 papers covering forests as environment from various aspects: forest ecosystems and biodiversity; forest hydrology; and natural disasters (landslides and debris flows et al) in mountains and their reduction. The publication will be of value to foresters, ecologists, hydrologists, landslide engineers and policy makers related to environments.