南京灵谷寺森林动态变化的研究

利用1951、1981和1991年的定点样带资料,对南京灵谷寺森林植物区系、物种多样性、显著度和年龄结构的动态变化进行了研究。40年来,种数由75种骤减到50种,复又增加到56种,个体数由5097株骤增到20585株,复又下降到3344株。而其Simpson指数和Shannon-Wiener指数的变化很小。显著度的分布均为对数级数型,优势种的作用非常明显,前6个种的显著度分别占了群落总显著度的75.4％、96.2％和84.4%。先锋树种马尾松(Pinus massoniana Lamb.)因幼苗的成活率低,显现衰退迹象,而黄连木(Pistcia chinensis Bge.)的年龄结构则表示该种群有再次占据优势的可能。群落中增长型常绿树种种群的出现,既反映了群落环境的改善,又意味着群落向地带性植被发育的可能性。

DYNAMIC CHANGE OF THE FOREST IN SPIRIT VALLEY, NANJING

The Changes of flora, species diversity, predominance and age structure of the forest in Spirit Valley, Nanjing were studied, based on the data collected in 1951, 1981 and 1991 from the same plot. During the 40 years, the number of species has been changed from 75 to 56, being 50 in 1981. The number of individuals from 5 097 to 20 585 and then to 3 344. Meanwhile, little variation was shown in both Simpson index and Shannon-Wiener index. All the distribution curves of predominance fit log series type, indicating important function of the dominant species. In fact, the predominance of the first 6 species respectively accounted for 75.4% ,96.2% and 84.4% of the total . Population of the pioneer species, Pinus massoniana Lamb. , showed a declining trend owing to its low survival rate of its seedlings. Instead, the age structure of Pistacia, chinensis Bge. forcasted its potential dominance in the future. Occurrence of ever-green broadleaved tree populations with advancing age structures not only showed the improvement of the habitat, but also the possibility of community development to zonal vegetation.