不同林龄马尾松人工林优势种径级结构及物种多样性分析

Analysis on Diameter Class Structure of Dominant Species and Species Diversity of Pinus massoniana Plantation at the Different Ages

采用空间代替时间的方法,以黔中山地孟关林场10a、20a、30a和36a的马尾松人工林为研究对象,通过设置12块20 m×20 m的典型样地,分析了马尾松人工林发育过程中径级结构与物种多样性的动态特征。结果表明:(1)马尾松人工林不同林龄阶段,优势种径级结构存在一定差异,10a林分呈单峰型结构,20a、30a、36a林分呈多峰型结构。(2)林下共有植物种类35科53属53种,其中灌木16科24属24种,草本20科29属29种,物种较丰富;不同林龄林分物种组成种类为:20a林分>10a林分>30a林分>36a林分。(3)随林龄增加,马尾松人工林物种丰富度指数先增大后减小,Shannon-Wiener指数和Simpson指数以及Pielou均匀度指数和Alatalo均匀度指数在10a～30a之间变化趋势相反,30a～36a之间变化趋势一致。

Taking the masson pine plantation 10a, 20a, 30a and 36a of mengguan forest farm in central Guizhou as the research object, by adopting the method of replacing time change with space change, we analyzed the dynamic characteristics of diameter scale structure and species diversity in the development process of masson pine plantation by setting 12 typical 20m by 20m plots. The results showed that:(1) the diameter grade structure of masson pine plantation was different at different age stages, with single-peak structure at 10a stand and multi-peak structure at 20a, 30a and 36a stands.(2) There are a total of 53 species in 53 genera and 35 families of plants under the forest, including 24 species in 24 genera and 16 families of shrubs, 29 species in 29 genera and 20 families of herbs, with relatively rich species. Species composition of stands of different ages: 20a stands > 10a stands > 30a stands > 36 a stands.(3) Species richness index of masson pine firstly increased and then decreased with the increase of forest age. Shannn-wiener index, Simpson index, Pielou evenness index and Alatalo evenness index showed the opposite trend between 10 a and 30 a, and the same trend between 30 a and 36 a.