Effect of the Complexity in Environmental System on Survival of Monimopetalum chinense, an Endangered and Endemic Species in China

Monimopetalum chinense (Celastraceae), a rare, endangered and protected species, is a woody climber of monotypic and endemic genus in China. It is found only on the south bank of the mid-lower Yangtze River extending from 28deg30´ to 30deg10´N and 114deg30´ to 118deg10´E. This paper deals with the effect of the complexity in environmental system on survival of M. chinense, including the characters of community and population, soil environmental factor, breeding system, genetic diversity, etc. The results of investigation indicate that: (1) It is an accompanying element in forest communities, and its distribution can be affected by some dominant elements e.g. Cunninghamia lanceolate, Pinus massoniana, Phyllostachys pubscens, Alniphyllum fortunei, etc. (2) The optimum habitat is in a strong acid area (pH values are from 4.55 to 5.57), and contains plenty of organic matter and nitrogen. Soil pH and organic matter are two limiting factors for survival and multiply of this species. (3) M. chinense habituates the warm and humid climate environment, of which are benefit clonal reproduction. While the soils are short of P and K elements that are influence sexual reproduction of this species. (4) In this study, a low level of genetic variation and a high level of genetic differentiation were detected in M. chinense. The habitat fragmentation since the end of Tertiary period, genetic drift of small population and the form of inbreeding reproduction would have contributed to such genetic differentiation among populations of M. chinense. Based on these findings, It is suggested that: (1) these populations with relatively high genetic diversity should be protected in situ; (2) introduction among populations for this species should be adopted; then, the genetic diversity of M. chinense can be conservation effectively.