Permalink : http://hdl.handle.net/2115/47768

KEYWORDS : distribution;gymnosperms;Kurils;Sakhalin;S-K index

Distribution patterns of nine species of gymnosperms native to Sakhalin and the Kuril Islands are analyzed quantitatively based on the examination of main Japanese herbaria. Pinus pumila and Larix gmelinii represent the most abundant species of gymnosperms in the regions. The Sakhalin-Kurils index (S-K index) was newly proposed for the comparison of the abundance of the species between Sakhalin and the Kurils. All S-K indices of gymnosperms show positive numbers reflecting more predominant coniferous forests found in Sakhalin than in the Kurils. For most species of gymnosperms; especially subarctic species, such as Abies sachalinensis, Larix gmelinii, Picea jezoensis and Juniperus communis, Sakhalin has functioned as a more important migratory route than the Kurils. But the Kuril Archipelago has similarly functioned as an important migratory route for Pinus pumila and Taxus cuspidata characterized by comparatively low S-K indices.