Lake Tanzawa and Mount Tanzawa Ōyama ― Nature Conservation Measures Mid-1990s

Lake Tanzawa and Mount Tanzawa Ōyama ― Nature Conservation Measures Mid-1990s

The natural environment conservation measures Kanagawa Prefecture sought to implement around Lake Tanzawa and Mount Tanzawa in the mid-1990s were a practical response to the contradiction between the pressure of use and environmental degradation facing nature in the Tokyo metropolitan area's suburbs. Designated as Tanzawa-Ōyama Quasi-National Park in 1965, the area saw expanding use for hiking and tourism. However, problems such as trail erosion, littering, and impacts from vehicle use had accumulated.

In response, Kanagawa Prefecture shifted its approach toward management-based conservation, centered on establishing a visitor center and conducting a comprehensive natural environment survey. The Tanzawa-Oyama Natural Environment Comprehensive Survey, conducted from 1993 to 1996, provided an integrated understanding of vegetation, wildlife, water environments, and actual usage patterns, laying the foundation for a scientifically grounded conservation plan.

The survey revealed serious issues: decline in understory vegetation due to increased Japanese deer populations, stagnation in forest regeneration, and soil erosion. These were complex problems not attributable to a single cause, clearly demonstrating the need to adjust human interaction rather than simply separating nature from use. The visitor center was positioned as a hub to change visitor behavior through nature interpretation and information provision. The concept of enhancing the quality of use to achieve conservation, rather than relying on access restrictions, symbolized the managed conservation approach that began spreading in the 1990s. The measures implemented at Lake Tanzawa and Mount Tanzawa-Ōyama are notable for translating the principle of protecting nature into concrete management techniques. The choice to control human use while accepting it as a given, in order to sustain nature near urban areas, was a representative example of the shift in environmental p
olicy during the mid-1990s.