Grasslands and Shrublands of Japan

Abstract

Abstract Natural or semi-natural grasslands and shrublands are small but widely distributed throughout Japan, although the forest vegetation is the potential climatic climax under the humid climates in the most parts of the county. Grasslands and shrublands have been formed by natural and anthropogenic disturbances and/or specific soil conditions in the Japanese archipelago. Since the last century, however, grasslands, especially semi-natural ones, have decreased in the area continuously, mostly due to land-use changes (abandonment, intensified use, afforestation and urban development) driven by socioeconomic growth in Japan. The rapid declines, along with fragmentation and degradation, of semi-natural grasslands have caused significant biodiversity loss as in the other Palaearctic regions but most of those grasslands and shrublands are not well protected. Natural grasslands and shrublands, on the other hand, have been protected from anthropogenic developments in general, but their area may decrease by climate changes in the future. The anti-disaster development, such as dams and embankments, reduced natural disturbances and have caused reduction and degradation of grasslands and shrublands in riparian and coastal areas. In some oceanic islands, feral goats have had significant negative impacts on grassland and shrubland vegetation. Some grasslands and shrublands on limestone and serpentine soils and on oceanic islands are often hotspots of endemic species whereas semi-natural, riparian and coastal grasslands harbor many plant and animal species which used to be found throughout Japan but now at high risk of extinction. Thus, in Japan, recent human activities largely degraded and reduced Japanese grasslands and shrublands which have high conservation values. To protect these invaluable ecosystems, a suite of activities have been initiated to promote biodiversity conservation and restoration in Japanese grasslands and shrublands.