[Population structure of endangered Monimopetalum chinense and its relationships with environmental factors]

Based on the field investigation data obtained from the typical plots of four community types, i. e. , secondary shrub, Phyllostachys edulis forest, Cunninghamia lanceolata forest, and Pinus massoniana forest, in the Zongli Village of Qimen County in Anhui Province, this paper studied the mean basal diameter and structure of Monimopetalum chinense population, and the effects of environmental factors on the population characteristics. The results showed that the mean basal diameter of M. chinense in the communities was in the order of P. edulis forest > P. massoniana forest > C. lanceolata forest > secondary shrub, and significantly larger in the two former forests than in the others (P < 0.05). The population structure of M. chinense also differed with habits. In secondary shrub and P. massoniana forest, the structure was a aptypical pyramid-like form, suggesting that the population was stable; in P. edulis forest, it was a spindle type, indicating that the population was at the early stage of declining; whereas in C. lanceolata forest, it was a typical pyramid-like form, with most young individuals in the population. The survival curve of the whole population belonged to Deevey II, suggesting that the population was in developing tendency with no declination. M. chinense preferred the sites with low altitude, high soil moisture and organic matter contents, gentle slope, and high coverage of tree layer; while frequent human disturbance decreased its natural regeneration and stability. Based on the results obtained, some preliminary protection suggestions were proposed.