The species composition of pine forests was studied in the eastern part of Shimane Prefecture. The changes on the species composition after the damage by pine wilting disease were discussed.
The species numbers of the overstory in heavy damaged pine forests was not different from that in no damaged forests. However, Symplocos lucida, Ilex integra and Castanopsis cuspidata have high occurrence rates as for evergreen broad-leaved trees, and Quercus serrata also has a high rate as for deciduous broad-leaved trees. 77 species appeared in the overstory of damaged pine forests and it was larger than the number in no damaged pine forests. The rate of deciduous broad-leaved species in both number and basal area became larger with the increase of damage rate. The deciduous broad-leaved species included many pioneer species. Furthermore, the species diversity of pine forests became higher with the recovery of vegetation after the damage.