To assess the effective vegetation management focusing on the conservation of Phengaris teleius habitats in Iwate Prefecture, we monitored plots adjacent to stands of P. teleius habitat since 2010. All of the plants in half of the all plots were mowed in June 2011. In same plots, all of the plants except Sanguisorba tenuifolia, a food plant of P. teleius, were mowed in June 2012 (experimental plots). The remaining half of the plots was not mowed (control plots). Plots were also established in P. teleius habitat; these plots had been mowed every November since 2006 (conservation plots). We surveyed the vegetation and environmental conditions in the experimental, control, and conservation plots. The results showed that photon densities of inside of plant communities in experimental plots were higher than in control and conservation plots. In addition, the incidence of shading the food plant was lower in experimental plots than in control and conservation plots. Mowing all plants in June of the last year and while leaving the food plant in June of this year considered to be an effective vegetation management approach, as this treatment improved photoenvironment and reduced competition.
