【Introduction】

Land abandonment and changes in management measures have caused biodiversity declines in semi-natural grasslands worldwide. In this study, we aimed to examine the effects of abandonment and change in management practices on environmental factors which in turn, influence plant diversity to discuss the mechanisms explaining plant diversity declines in meadows.

【Methods】

The study was conducted in the Kaida Plateau, one of the most famous native-horse breeding sites, Nagano Prefecture. Traditionally, meadows had been maintained by both mowing and burning. Many meadows are now abandoned or maintained with only burning or mowing. We compared plant species diversity among meadows with different management practices. We set 17 study sites (sites with both burning and mowing, burning or mowing only, and abandoned sites. We established 6 plots at each site and investigated plant species diversity and environmental variables(plant height, biomass, soil pH and moisture) in early summer and autumn, 2011.

【Result & Discussion】

Species richness was highest in meadows with traditional practices and lowest in abandoned sites. Plant height, which was reduced by mowing and increased with burning, strongly influenced species richness and the effects were different between seasons. According to our results, we discuss effective management to keep meadows with high plant diversity.