Traditional Ecological Knowledge Maintains Useful Plant Diversity in Semi-natural Grasslands in the Kiso Region, Japan

Wild plant species provide a variety of ecosystem services that contribute to human well-being. However, much of the legacy of traditional ecological knowledge (TEK) in Japan is rapidly being lost because of environmental changes; therefore, it is important to study the relationship between TEK of ecosystem management practices and plant diversity. Our study area is located in the southwest of Nagano Prefecture, Japan. We compared plant diversity among three land management types including traditional, labor-saving, and land abandonment sites, where we recorded 103 useful plant species based on interviews concerning the traditional use of local ecological resources; among them, 45 species are used for horse livestock, 32 for agriculture, 16 as edible plants, and 19 for manufacture of diverse every-day life goods. Data analyses demonstrated that useful plant diversity was significantly higher in the traditional sites than in other sites. We found highly diverse traditional uses of plant species (e.g., edible plants, horse feed, and rainwear) provided by TEK of local management. These results imply that when local farmers perform traditional management practices, they increase plant species diversity. With our work we investigated the effect of the loss of cultural values and the impact of biodiversity changes on the opportunities that people have to use ecosystem resources in Japan. This aspect particularly highlights the urgency of reconnecting nature and people. Conservation planning based on TEK has been and will be vital in addressing the goal of reducing biodiversity loss on a global scale.