Stand structure of a broadleaved forest with sasa-type floor after mass mortality by oak wilt disease

The current status of a broadleaved forest after mass mortality caused by oak wilt disease was investigated in the Tango Peninsula in central Japan. Sasa palmata, a species of dwarf bamboo, dominated the forest floor and had been supposed to inhibit the regeneration of tree species, including Quercus crispula. Small stems and saplings of tree species were, in fact, not abundant. While the small stems whose diameter at breast height was less than 10 cm were very abundant, most were Clethra barbinervis, Viburnum furcatum, Benthamidia japonica, Lindera umbellata, Rhododendron lagopus var. niphophilum or Cephalotaxus harringtonia var. nana; all these species except B. japonica were subtree or shrub species. Tree species were not abundant in the layer below breast height. The stand structure suggested that the regeneration of tree species including Q. crispula was difficult, and that the current status would last at least until simultaneous death of S. palmata.