Inter-specific Association And Vertical Distribution Among Key Medicinal Plants Of Three Countries In Southwest Of Hainan Island

Hainan southwest region including three counties: Le-dong, Dong-fang. Chang-jiang, they are near by North Bay and the coastline of371.35km. In this paper,220kinds of the medicine plants of the key medicinal plants prescribed by The Fourth National Medicine Resources survey in China were studied in Hainan southwest region. The vertical distribution, ecological niche, inter-specific association and ecological association of sequences of medicinal plants were also studied. The results are as follows:(1) There were233kinds of medicinal plants in Le-dong country, which were94kinds of key medicinal plants and139kinds of common medicinal plants; There were196kinds of medicinal plants belong to Dong-fang city which were89kinds of key medicinal plants and107kinds of common medicinal plants; There were222kinds of medicinal plants in Chang-jiang country, which were92kinds of key medicinal plants and130kinds of common medicinal plants. In short, the different medicinal plants species have different distributions with altitude gradient different degrees.(2) The results showed that the niche breadth and ecological adaptability at different altitudes of different key medicinal plants were quite different.(3) There were50kinds of key medicinal plants which frequency greater than0.05in the three counties. The1225species pairs were consisted of50kinds of key medicinal plants. Among the1225species pairs, there were436pairs showed positive correlation and789pairs showed negative correlation and positive and negative association ratio were0.552in Le-dong country; There were420pairs showed positive correlation and805pairs showed negative correlation and positive and negative correlation ratio was0.522in Dong-fang city; There were358pairs showed positive correlation and867pairs showed negative correlation and positive and negative association ratio were0.413in Chang-jiang country. The study of Inter-specific association results indicate that the key medicinal plants pairs showed out more loosely inter-specific association between two medicinal plants species and independent distribution of medicinal plants.(4) The de-trended correspondence analysis (DCA) based on2X2contingency tables of species presence/absence and quadrat data. According to the de-trended correspondence analysis (DCA), the50kinds of key medicinal plant species were divided into three ecological species groups:Group â… , the high-altitude species; Group â…¡, the Mid-elevation species; Group â…¢, the low altitude species. The division of ecological species groups basically reflects the distribution of plants and the relationship between plants species and environment in these countries. The species of Group II and Group III which were mostly distributed in the secondary environment; The species of groups I were shade-tolerant type species which were mostly distributed in the natural forest region. Coefficient of community of two countries among three counties for the same ecological species group as follows: in Group I, Le-dong-Dong-fang was0.56, Le-dong-Chang-jiang was0.54, Chang-jiang-Dong-fang was0.45; In group II, Le-dong-Dong-fang was0.40, Le-dong-hang-jiang was0.35, Chang-jiang-ong-fang was0.57; In group â…¢, Le-dong-Dong-fang was0.44,Le-dong-Chang-jiang was0.29, Dong-fang-Chang-jiang county was0.56.The ecological characteristics of the wild medicinal plants were revealed by the results of these studies in these counties of Hainan southwest region. Each species has its own specific distribution area, ecological adaptability and a certain similarity. These results can provide a scientific basis for protection and artificial cultivation of medicinal plants in future.