秦岭火地塘林区华山松人工林与天然次生林群落特征比较

Comparison of Community Characteristics of Plantation and Secondary Forest of Pinus armandii in Huoditang Forest Region of Qinling Mountain

采用样地调查法对秦岭火地塘林区处于中龄阶段的华山松人工林与天然次生林群落特征进行比较研究。结果表明:(1)华山松天然次生林群落有维管束植物38科64属82种,人工林群落有维管束植物30科55属71种,两个群落共有种为53种,相似系数为0.55。(2)华山松人工林群落灌木层和草本层的Maglef指数、Simpson指数、Shanon-Wiener指数和Pielou均匀度指数与天然次生林群落无显著差异,但人工林乔木层的4个多样性指数显著低于次生林。人工林的4个多样性指数表现为灌木层>草本层>乔木层的规律,天然次生林表现出灌木层>乔木层>草本层的规律。(3)在生活型谱上,人工林与次生林的高位芽、地上芽、地面芽、地下芽和一年生草本的差异均不显著,但是天然次生林的中小高位芽植物比例显著高于人工林,矮高位芽植物相反。(4)在垂直结构上,天然次生林乔木层的树种组成和灌木层的天然更新幼苗量较人工林丰富,两个群落乔木层华山松种群的平均高度以及乔灌草三层的盖度无显著差异。(5)在水平结构上,人工林华山松种群的空间分布格局为均匀分布,胸径一致,为纯林;天然次生林华山松种群空间分布格局为聚集分布,与华椴和锐齿栎等树种水平镶嵌,形成异龄混交林。(6)天然次生林群落的自然构成系数为3.20,顶极树种比例为34.7%,人工林群落的自然构成系数为1.49,顶极树种比例为22.7%,两个群落差异极显著,且天然次生林群落处于先锋群落的中后期阶段,人工林群落尚处于先锋群落的初期阶段。研究表明,经过40年的恢复,两个群落整体上已具有一定程度的相似性,物种组成已比较接近,灌木层和草本层已无显著差异,两者主要差异在乔木层和演替状态上,天然次生林乔木层树种丰富,群落演替速度较人工林快。

The community characteristics of the Pinus armandii plantation and the secondary forest were comparatively studied by standard quadrat method in Huoditang Forest Region.The results were shown as follows：（1）Secondary forest consisted of 82 vascular species in 38 families and 64 genera,whereas the plantation included 71vascular species in 30 families and 55 genera.A similarity index of 0.55 was obtained with 70 co-occurring species.（2）The maglef index,simpson index,Shanon-Wiener index and pielou evenness index of shrub and herb were not significant difference between the plantation and secondary forest.Which in arbor layer of plantation were significant lower than that of secondary forest.In the plantation,the four diversity indexes were in the order shrub layer〉herb layer〉arbor layer,which in secondary forest were in the order shrub layer〉arbor layer〉herb layer.（3）In life form spectrum,phanerophyte,chamaephyte,hemicryptophyte,geocryptophyte and therophyte were not significant difference between the plantation and secondary forest,but mesophanerophyte and microphanerophyte of secondary forest were significant higher than that of the Plantation by contrast of nanophanerophyte.（4）In the vertical structure,tree species composes in the arbor layer and number of generation in the shrub layer of secondary forest were richer than that of plantation.Mean height of Pinus armandii and cover of arbor layer,shrub layer and herb layer were not significant difference between plantation and secondary forest.（5）In the horizontal structure,the spatial pattern distribution of Pinus armandii population in the plantation was uniformly distributed,which was aggregate distribution in secondary forest.In the secondary forest,Pinus armandii was different aged population mixed with Tsuga chinensis,Tilia chinensis,Quercus aliena var.acuteserrata and so on.While in the plantation,DBH class of Pinus armandii was uniform and tree species were simple.（6）The compose index of secondary forest community was 3.20,higher than that of plantation of 1.49.The ratio of the climax tree in the secondary forest was 34.7%,higher than that of plantation of 22.7%,which indicated that secondary forest was on the late stage of the pioneer community,while plantation was on the early stage of the pioneer community.After 40 a recovery,two communities had high similarity and their distinction was in the arbor layer and succession stage.The tree species of secondary forest were richer in the arbor layer and succession speed was faster than that of plantation.