4. DISCUSSION
In this study, we investigated the elevational distribution of multi-plant groups in the Yatsugatake Mountains to determine whether pertinent elevation hypotheses could substantiate the existing elevational patterns of the plant groups occurring there. The plant groups showed different responses to the elevational gradients and climatic factors in the study site. Regarding the elevational changes in alpha diversity, none of the plant groups exhibited elevational patterns corresponding to those expected based on mass and mid-domain effects. The elevational range of all the plant groups did not increase with elevation, disproving the application of Rapoport’s elevational rule to the distribution of plant groups in the study site. In contrast, the alpha diversity of all the plant groups was significantly affected by the climatic factors.