Study on the distribution and the population expansion of Ailanthus altissima, an alien tree species, in Japan.

阐明了外来树种Ailanthus altissima在日本的分布和种群扩展情况。在日本47个县均有分布，山梨县口府盆地每平方公里900目占29.8%，其生长位置由土地利用决定。在日本，主要建议将两种遗传上不同的品系引入每个种植区。寇府盆地各小居群之间存在遗传分化，表明寇府盆地各小居群的创立者都是少数个体。在顺南市山口县，该树种通过吸根无性繁殖不到50 m。

The distribution and the population expansion of Ailanthus altissima, an alien tree species, in Japan were clarified. This species is distributed all 47 prefectures in Japan and 29.8% of 900 meshes of one square km in Kofu basin, Yamanashi Pref. Its growing location was defined by land utilization. Mainly two genetically different lineages were suggested to be introduced to each growing area, in Japan. The little populations in Kofu basin were genetically differentiated from each other and it suggests that small number of individuals were founder of each population in Kofu basin. In Shunan-city, Yamaguchi Pref, this tree species clonally propagated less than 50 m by root sucker.