Habitat conditions and regeneration regime of Betula schmidtii （Schmidt birch） forest on the steep ridges of the Jobu Mountains in central Japan

Abstract

Betula schmidtii （Schmidt birch） is a broadleaved tree similar to Betula platyphylla var. japonica and is mainly distributed on the steep rocky ridges of the Jobu Mountains in central Japan.　This study elucidates the habitat conditions and regenerations of Betula schmidtii stands, focusing on the forest structure and tree population establishment.　On the steep rocky ridges, Betula schmidtii grows on poor soils and gently inclined surfaces in contrast to the local dominant species Quercus serrata.　Under these conditions, the local dominant species （Quercus serrata） lost its complete dominance.　Betula schmidtii stands were composed of seedlings, saplings, and young and mature low-statured trees.　In summary, we conclude that Betula schmidtii trees are maintained by successive regeneration and that they represent a local climax forest spreading across the Jobu Mountain’s steep rocky ridges.