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采用样地调查法对比研究了秦岭火地塘林区外来树种华北落叶松人工林与乡土树种华山松人工林及华山松天然次生林群落特征差异。结果表明:华北落叶松人工林群落与华山松天然次生林群落的相似性系数仅为0.11,华山松天然次生林与华山松人工林的物种数量均明显高于华北落叶松人工林(P<0.01);华山松天然次生林和华山松人工林乔、灌、草层的Margalef指数、Simpson指数、Shannon-Wiener指数和Pielou均匀度指数均显著高于华北落叶松人工林(P<0.001),而前两者之间灌木层和草本层的4个多样性指数的差异不显著(P>0.05);华北落叶松人工林的自然构成系数最低(0.3),华山松天然次生林的自然构成系数最高(5.2),华山松人工林的自然构成系数为3.5,三者存在极显著差异(P<0.001)。说明外来树种华北落叶松引种造成秦岭森林群落物种丰富度、植物多样性和林分自然化程度降低,自然次生演替或乡土树种人工林较外来树种人工林更有利于林下植被的恢复。
The characteristics of community differences between Pinus armandii plantations and native species of Pinus armandii forest and Huashan pine secondary natural forests were studied by means of plots survey in Huoditang forest region of Huoditang in the Qinling Mountains. The results showed that the similarity coefficient of Larix principis - rupprechtii plantation community and natural Pinus armandi community was only 0.11. The species numbers of both natural secondary forest and Pinus armandii plantation were significantly higher than those of Larix principis - rupprechtii plantation (P <0.01). Margalef index, Simpson index, Shannon-Wiener index and Pielou evenness index of the natural secondary forest and the Pinus armandii plantation were significantly higher than those of the Larix principis-rupprechtii plantation (P <0.001), while the former two (P> 0.05). The natural constituent coefficient of Larix principis-rupprechtii plantation was the lowest (0.3), and the natural constituent coefficient of Larix principis-rupprechtii natural forest was the highest (5.2) The natural composition coefficient of Pinus armandi plantation is 3.5, there is a very significant difference among the three (P <0.001). The introduction of exotic tree Larix principis-rupprechtii could lead to species richness, plant diversity and naturalization of the forest community in Qinling Mountains. Natural secondary succession or native species plantation was more beneficial to the restoration of understory vegetation than the native plantation.