浙南高山森林空间结构分析

Spatial Structure of Alpine Forests in Southern Zhejiang

以浙江南部景宁畲族自治县高山森林的乔木林为研究对象,设置标准地39个,包括针叶林、针阔混交林、常绿阔叶林和常绿落叶阔叶混交林4类森林,应用V_Hegyi竞争指数、全混交度和聚集指数,分析4类森林的空间结构特征及其差异。结果表明:1)4类森林的径级与竞争指数均符合幂函数分布,随径级增大,各森林类型的竞争指数减小;针叶林、针阔混交林、常绿阔叶林和常绿落叶阔叶混交林的竞争指数分别为6.96、7.07、7.35和7.22,均呈现低度竞争态势,且4类森林的竞争指数均无显著差异;2)针叶林、针阔混交林、常绿阔叶林和常绿落叶阔叶混交林的全混交度分别为0.31、0.46、0.43和0.50,均呈现低度混交状态,常绿落叶阔叶混交林、常绿阔叶林和针阔混交林的全混交度均显著高于针叶林;3)4类森林的聚集指数均小于1,呈现聚集分布格局,不同森林类型的聚集指数无显著差异。在制定浙南高山森林的空间结构调控措施时,应综合考虑各森林类型的竞争、混交和分布格局状态,以达到精准决策和合理制定经营措施的目的。

The alpine forests occurring in Jingning She Autonomous County in southern Zhejiang were used as the research objects,and 39 standard sample plots were set up,including four forest types:coniferous forest,coniferous and broad-leaved mixed forest,evergreen broad-leaved forest,evergreen deciduous broadleaved mixed forest.The spatial structure characteristics of the four forest types and their differences were analyzed by applying the V_Hegyi competition index,complete mingling and aggregation index.The results showed that 1)the forest diameter at breast height and the competition index(CI)of four forest types conformed to a power function distribution,and the CI of each forest type decreased with the increase of the diameter level.The values of CI of four forest types(in the order of above mentioned)were 6.96,7.07,7.35 and 7.22,respectively.All four forest types showed low competition and there were no significant differences in CI among the four forest types.2)The complete mingling of four forest types were 0.31,0.46,0.43 and 0.50,all four forest types showed low degree of mingling.The degree of complete mingling of coniferous forest was significantly lower than the other three forest types.3)The spatial distribution of the four forest types showed aggregated distribution pattern,and there was no significant difference in aggregation index among different forest types.When formulating the spatial structure regulation measures for the alpine forests in southern Zhejiang,the state of competition,mingling and distribution pattern of each forest type should be considered comprehensively in order to achieve the purpose of accurate decision-making and formulation of management measures.