徐州市侧柏人工林主要树木种群种间联结性

Inter-specific Association between Dominant Tree Populations of Platycladus orientalis Plantations Growing in Xuzhou City

通过2×2联列表,运用总体方差比率、联结系数、种间共同出现百分率和χ2检验等指标对徐州市侧柏人工林主要树种的种间关系进行了研究.结果表明:现阶段侧柏人工群落乔灌两层主要树种间总体上呈负联结,绝大部分种群种间联结性不显著,独立分布的较多;侧柏除与灌木层中的朴树种群联结性显著外,与其它种群间的联结性均不显著,反映了侧柏较强的生态适应性;徐州侧柏人工林现阶段仍处于演替的初期阶段,其向天然次生群落演替的速度极为缓慢,树种选择与配置是加速其植被恢复和改造的关键.

Based on 2×2 contingency table, this paper conducts some analyses of the inter-speciflc association between dominant tree populations of Platycladus orientalis plantations growing in Xuzhou City, by employing some indices such as collectivity variance ration, association coefficient value and percentage co-occurrence value and Χ^2-test. The results show that the collectivity variance rations of the arbor and shrub populations of existing Platycladus orientalis communities are of a negative association; that the interspecific association is not significantly correlative in most of the species and most of the tree species distribute themselves independently; and that except the species of Zizyphus jujuba var. spinosa and Firmiana simplex in the shrub layer, Platycladus orientalis is not significantly associated with other species, which indicates that it has stronger ecological adaptability. Therefore, existing communities of Platycladus orientalis plantations are still unstable and changing slowly towards natural secondary forest ; it is critical to choose and set tree species for afforestation and reconstruction of actual Platycladus orientalis forests in Xuzhou City.