抄録
In the previous paper, the authors carried out identification of C3 and C4 species of the grass family in Japan, then investigated the geographical distribution of them with special reference to climatic conditions. In the present paper, by means of the same method, we tried to investigate the geographical distribution of C3 and C4 species of the grass family occurred in Korea and Taiwan which are located at near Japan, Hainan and Java which are located at the subtropics or tropics of South East Asia. As to the distribution of C3 and C4 species along altitudinal gradient in Java, special analysis was carried out. Obtained results are as follows : 1) The districts concerened with the present study exclusively belong to the South East monsoon regions, especially Taiwan, Hainan and Java belong to the wet-subtropics or tropics. These districts are comparatively poor in no. of species belonging to subfamily Eragrostoideae, in contrast, abundant in that of Panicoideae. It is noted that the proportion of species of tribe Andropogoneae in subamily Panicoideae are comparatively abundant, and also it should be noted that no. of C3 species of Panicoideae are rather abundant. 2) In general, increases in percent C4 with latitudinal descension occurred. The latitude of Java is lower than that of Hainan. However, in spite of lower latitude, Percent C4 of Java (66%) is lower than that of Hainan (81%). In Java, there are many high mountains (3000-4000 m), but Hainan is not so high, its only 1800 m at the highest. This fact drops percent C4 of Java under that of Hainan. The same situation is applied to the case of comparison between Taiwan (60%, 22-25°N) and Ishigaki (70%, 24°N). 3) In Java, percent C4 decreases markedly with ascension of altitude. This fact is caused by the increase of no. of species belonging to Festucoideae. It is considered that climatic temperature falls down with ascension of altitude, and the no. of species belonging to Festucoideae which agree with cool climatic conditions increase rapidly at higher latitude. In spite of their latitudinal sites. Java and Taiwan have so many species belonging to Festucoideae. This fact supports the above mentioned deduction.
