鄂西南五种野生荚蒾属植物种群结构与动态特征研究

o explore the population quantitative characteristics and regional distribution of wild Viburnum plants in southwest Hubei, and reveal the survival status and development trend of the following five Viburnum species: V. erosum, V. betulifolium, V. sympodiale, V. setigerum and V. dilatatum. A total of 27 hm2 permanent monitoring stands were set up in Jinzishan National Forest Farm, Mulinzi National Nature Reserve and Qizimei Mountain National Nature Reserve in southwest Hubei. The age structure, dynamic quantitative analysis and static life table of five Viburnum species were used to explore the population structure, dynamic characteristics and future development potential of Viburnum plants. The results were as follows: (1) The distribution area and population size of Viburnum plants in southwest Hubei are significantly different. (2) The age structure of the five Viburnum species displays as the pyramidal type summarized from population structure and dynamic analysis.. The number of individuals of each population is large at the young stage (89.48% of V. erosum in Jinzi Mountains, 76.38% of V. betulifolium, 67.24% of V. erosum in Mulinz, 62.11% of V. dilatatum, 56.53% of V. sympodiale, 58.44% of V. setigerum), and only a small proportion of individuals (0.18% of V. erosum in Jinzi Mountains, 0.85% of V. betulifolium, 3.29% of V. erosum in Mulinz, 3.97% of V. dilatatum, 8.37% of V. sympodiale, 2.79% of V. setigerum) in the older stage. The young stage plants of five Viburnum species all have strong growth potential but are sensitive to external disturbances. (3) The survival quantity of the five Viburnum species is decreasing monotonically with increasing age class presented by static life tables. Except for V. setigerum, the life expectancy reaches peak at the younger age, all other Viburnum species populations reach the peak at the middle age. The change trend of mortality rate and disappearance rate are similar, but the fluctuation of disappearance rate and mortality curve are different among different species. The survival curves are tended to be Deevey- type. (4) The four survival function curves show that all five Viburnum species populations exhibited a substantial decrease in the early stage, stabilization in the middle stage, and decline in the late stage. To sum up, Viburnum species are abundant plant resources in southwest Hubei. Therefore, it is scientific and feasible to exploit Viburnum plants rationally. In the young stage, artificial thinning can be carried out appropriately to improve the preserving rate. During the stable middle stage, the dominant and species which have good ornamental characters can be selected for appropriate development and utilization. However, some species need to be protected to maintain biodiversity in this area.