The Coupling Relationship Between Tree Species and Size Differentiation Diversity of Three Types of Natural Broadleaf Mixed Forests and Terrain
Based on the continuous forest resource inventory data of Zhejiang Province in 2021,this study selected 969 sample plots of natural broadleaf mixed forests,categorized as young and middle-aged forests.The plots were divided into three vegetation types:evergreen broadleaf forest,deciduous broadleaf forest,and evergreen-deciduous broadleaf forest.Vari-ance analysis and Pearson correlation analysis were used to examine the relationship between terrain and tree species diver-sity and size differentiation in these forests.The results showed that:(1)There were significant differences in species di-versity indices among the three vegetation types(P＜0.05).The coefficient of variation in diameter at breast height(DBH)and DBH evenness of deciduous broadleaf forests were significantly higher than those of evergreen broadleaf forests(P＜0.05),while the Shannon-Wiener index of DBH for evergreen broadleaf forests was significantly higher than that of decidu-ous broadleaf and evergreen-deciduous broadleaf forests(P＜0.05).(2)With increasing altitude or slope,richness,Shan-non-Wiener index,and Simpson diversity index of the three vegetation types exhibited a significant increase(P＜0.05),while the Pielou evenness index showed no significant difference in deciduous broadleaf and evergreen-deciduous broadleaf forests.Aspect had no significant effect on tree species diversity.(3)As elevation increased,overall trends showed a de-crease in the coefficient of variation for DBH and DBH evenness across the three vegetation types,while the Shannon-Wie-ner index for DBH showed the opposite trend.From sunny slopes to shady slopes,the DBH evenness index of evergreen broadleaf and evergreen-deciduous broadleaf forests generally increased.With increasing slope,the coefficient of variation in DBH for deciduous broadleaf forests and the DBH evenness for the three vegetation types decreased,while the Shannon-Wiener index for DBH in deciduous broadleaf forests showed the opposite trend.Altitude and slope had significant effects on the number of tree species and DBH evenness in the three vegetation types.However,they had no significant effects on the species evenness of deciduous broadleaf and evergreen-deciduous broadleaf forests,nor on the coefficient of variation for DBH in evergreen broadleaf forests.Aspect mainly affected the DBH evenness of evergreen broadleaf and evergreen-de-ciduous broadleaf forests.
万方数据
维普
