黄土丘陵区人工和天然油松林物种多样性比较

以甘肃省正宁县中湾林场为研究点,采用标准样地调查法,应用物种丰富度、Simpson指数、Shannon-Wiener指数、Pielou均匀度指数分析了人工油松林和天然油松林群落α多样性动态特征、群落结构特征及群落相似性。结果表明,人工油松林和天然油松林均具有比较丰富的物种组成,分别为69种和57种,两种群落多样性指数变化规律一致,依次为灌木层、草本层和乔木层。群落总体的多样性除Pielou指数的最大值出现在阴坡的天然林外,群落总体的物种丰富度、Simpson指数、Shannon指数均在阴坡的人工林达到最高峰,表明生长在阴坡的人工油松林,其群落总体的多样性指数较大。不同坡向的天然林群落相似性显著高于处于不同坡向的人工林,无论在物种组成还是在多样性及群落空间结构上,天然林和人工林均具有较高的相似性。在黄土丘陵区通过适当人工抚育措施可以有效地增加林下植被的种类和盖度,促进人工林的生长发育。

Comparison of the Species Diversity of Natural and Artificial Pinus tabulaeformis in Hilly Loess Regions

The feature of the community diversity not only gives insight to evaluate the quality of the forest,but also plays a crucial role in increasing the productivity of the forest.The community diversity and the comparability indices of the natural Pinus tabulaeformis and artificial Pinus tabulaeformis in Ziwuling region were comparatively studied by standard quadratic method and using the methods of species abundance,Simpson index,Shannon-Wienner index,Pielou's evenness index.The results showed that the artificial Pinus tabulaeformis and natural Pinus tabulaeformis both had the quite rich species composition,they are 69 and 57,respectively.This two forest types had similar trends of the community diversity as shrubs >herbs> trees.In order to measure the whole community diversity,the average of the relative thickness of the leaf layer and the relative coverage of each living form were used as weighting parameters.The results showed that the artificial Pinus tabulaeformis in shade slope had the highest community diversity.The result of similarity comparison indicated that there had the highest comparability indices of natural Pinus tabulaeformis forests in different slopes.Regardless of the species composition and the community spatial structure of the natural forest and the artificial forest,this two forest types had the high similarity.It was proved that the proper artificial measures can increase both the quantity and the coverage of the forestland and the development of the artificial forest.