森林景观对区域生物多样性的影响

森林资源减少是区域生物多样性下降的重要原因之一,明确影响区域生物多样性变化的关键森林景观因子对深入了解森林景观对区域生物多样性的影响机制具有重要意义。以鄱阳湖生态经济区为研究对象,从森林景观的数量、质量、分布等方面选取11个指标,通过相关分析、弹性分析和线性回归分析研究森林景观指标与区域生物多样性的关系。结果表明,所选用的表征森林景观的指标,除平均树高外,均与区域生物多样性显著相关(显著水平0.05),与森林密度(每公顷株数)的相关性最好;区域生物多样性对平均胸径变动的敏感程度最强,森林景观分布均衡度次之,有林地面积最弱;采用逐步回归法,建立了多元回归方程,表明在多因素综合影响下,影响区域生物多样性的主要指标作用大小为:活立木蓄积量每公顷株数平均胸径森林景观分布均衡度林地面积。研究结论为科学管理森林景观,提高区域生物多样性提供了一定依据。

Effect of forest landscape on regional biodiversity

Reduction of forest resources is one of the important reasons for the regional biodiversity.Therefore,identification of factors affecting regional biodiversity in the forest landscape is crucial.Taking Poyang Lake Eco-economic Zone as a case study area,11 indices pertaining to the aspects of forest landscape quantity,quality and distribution were selected for evaluation.Correlation analysis,linear regression analysis and flexibility analysis were used to investigate the relationship between forest landscape indices and regional biodiversity.The results indicated that the indices chosen to represent forest landscapes were significantly correlated with the regional biodiversity (P＜0.05) except the average tree height.The forest density (the number per hectare) showed the highest correlation with regional biodiversity.Regional biodiversity was most sensitive to the average diameter at breast height,followed by forest landscape distribution equilibrium degree.The area of forestland had the lowest sensitivity to regional biodiversity.Multiple regression equation was established using the stepwise regression method and it showed that the sequence of indices affecting regional biodiversity follows by the growing stock volume,number per hectare,average diameter at breast height,forest landscape distribution equilibrium degree,and the area of forestland.