Plant Species Composition And Diversity Of Yunnan Rubber Plantations

Rubber plantation is an important plantation ecosystem in the tropical area with Hevea brasiliensis as the only dominant species. In recent years, as the planting area of rubber plantation continues to expand, its ecological benefit have also aroused the attention of scholars, especially in its impact on biodiversty when the economic benefit of rubber industry has been paid more attention. Nowadays, Yunnan province is the largest province of planting area of rubber plantation in China,so it is urgent and important to study the plant species composition and diversity in Yunnan rubber plantations. Based on the plant investigation of 56 rubber plantation plots (10m × 10m) in Honghe, Xishuangbanna,Puer, Lincang and Dehong, the plant species composition and diversity and the influencing factors of the distribution of main species were analyzed,and the plant diversity of rubber plantations in Yunnan, Guangdong and Hainan province were compared in this paper. The main results of this study are as follows:(1) Plant species were rich and plant composition was complicated in Yunnan rubber plantations. There were 114 families, 328 genera, and 472 species of vascular plants,including 57 species of trees, 123 species of shrubs, 241 species of herbs and 51 species of vines in the plantations. The plants of Papilionaceae, Compositae and Rubiaceae were dominant in the plantations because of the influence of natural environment and human interference, especially the direct human interference. The most common species were Eupatorium odoratum,Cyrtococcum patens,Paspalum conjugatum, Urena lobata,Centotheca lappacea in the plantations.(2) The plants uses were extensive and the plants were with high development and utilization value in the plantations. The species numbers of medicinal plants, industrial plants, ornamental plants, edible plants, forage plants and ecological plants were 356, 103,81, 80, 32 and 24 respectively in the plantations. There were lots of plants of high value,such as Ficus hirta, Plumbago zeylanica, Elephantopus scaber and Peperomia pellucida of medicinal plants, Ricinus communis, Manihot esculenta of industrial plants,Pseudodrynaria coronans, Caladium bicolor of ornamental plants, Coffea canephora,Hylocereus undatus of edible plants, Crotalaria ferruginea, Paspalum conjugatum of forage plants, Pueraria lobata, Calopogonium mucunoides of ecological plants, which can be exploited properly.(3) The property of tropical zone was evidently presented and the tropical Asia infinity and endemism existed in the plantations. The seed plants’ R / T of family level,genera level and species level were 7.14,10.74 and 15.38 respectively. Also, there were 46 genera and 211 species of tropical Asia. What’s more, 32 families of cosmopolitan and 59 Chinese endemic species were also included. The characteristics of tropical zone were slightly stronger than that of Guangdong and was sharply weaker than that of Hainan. And the tropical Asia infinity and endemism of Yunnan rubber plantations were both the strongest in the three communities. In addition, a certain similarity also existed in the families composition of three communities.(4) There were significant correlations between plant diversity and temperature,slope and other factors in Yunnan rubber plantations. The richness index, Shannon-Wiener index and Simpson index of the rubber plantations in Xishuangbanna were the highest and lowest in Honghe. The Shannon-Wiener index and Simpson index of period 8 to 10 years were lowest in all ages. The richness index,Shannon,Wiener index and Simpson index of altitude 500 to 700 m were highest. And the diversity of slope greater than 25° was obviously higher than it of slope between 2 to 15°.(5) The plant diversity was not low in Yunnan rubber plantations in general. There was little difference in plant diversity of the Yunnan rubber plantations and Hainan rubber plantations, which were higher than that of the Guangdong rubber plantations, and there was little difference in plant diversity of the rubber plantations and rubber plantations intercropping Camellia japonica in Yunnan, which were higher than that of the Eucalypt plantations. A certain similarity existed in the species composition of rubber plantations in Honghe, Xishuangbanna, Puer, Lincang and Dehong, and the coefficients of similarity between Lincang and Puer was 0.47 in species composition. When the coefficients of similarity were compared in rubber plantations, rubber plantations intercropping Camellia japonica and Eucalypt plantations, the coefficient of similarity between rubber plantations and rubber plantations intercropping Camellia japonica was highest. The temperature,precipitation, altitude and other five influencing factors totally explained 20.28% in main species distribution and the correlations between altitude and species distribution and between precipitation and species distribution were high.