キイチゴ属植物倍数体の地理的分布

II. 垂直分布について

抄録

1) The relation between the vertical distribution and the polyploidy of Rubus has been investigated in six mountains which are from about 1000 to 2000 meters above the sea-level in Ehime Prefecture in Japan, and as the result the following data have been obtained.
2) The upper limits of vertical distributions of the nine diploid species of Rubus are found at least more than 900 meters high, while those of four of the tetraploid and hexaploid species are less than 850 meters at the highest. Though the upper limit of vertical distributhion of R. pectinellus (6X) is 1250 meters high, yet this is much lower than those of most diploid species. The average altitude of upper limits of the diploids is 1524 meters, while that of the polyploids is 750 meters, with the ratio of two to one, and the average distance between the upper and the lower limits of vertical distributions of the former is 650 meters, while that of the latter only half as many.
3) When all these data are taken into account, it may be safely said that the diploid species are generally distributed from low to high regions of the mountains, while the ployploid species are confined to the lower. And one of the chief reasons of this phenomenon may be that many of the former pass the winter with the winter buds, while the latter evergreen, and so they are more apt to be affected by bad environment than the former.