小兴安岭典型林分空间结构特征及其对灌草多样性的影响OA

Based on the measured data of 5 fixed plots,the relationship between plant diversity and stand spatial struc-ture in five forest types of Betula platyphylla forest,Pinus koraiensis-Abies-Picea forest,Pinus koraiensis-broadleaved mixed forest,Hard broad-leaved forest and Picea-Abies forest in Langxiang National Nature Reserve of Xiaoxing'an Mountains was studied.Three indexes of uniform angle index,size ratio index and mingling index were used to describe the stand spatial structure,and three indexes of Simpson diversity index,Shannon-Wiener diversity index and Pielou evenness index were used to describe the plant diversity.On this basis,the correlation analysis was used to explore the influence of different stand spatial structures on plant diversity,and the domain structure factors affecting plant diversity were found out.The results showed that there was no significant difference in the uniform angle index and size ratio index among the five forests.There was a significant difference in the mingling index between Pinus koraiensis-Abies-Picea for-est and hard broad-leaved forest(P<0.05),but the five forests all formed a mixed,aggregated and competitive growth state.The species composition of woody plants in each stand was rich.The tree layer of the Pinus koraiensis-broadleaved mixed forest has the highest Shannon-Wiener index,Simpson index,and Pielou index,while the shrub layer of the Picea-Abies forest has the highest Shannon-Wiener index.and the Pielou index of the shrub layer of Pinus koraiensis-Abies-Picea forest was the highest.The Shannon-Wiener index and Simpson index of the tree layer in the Betula platy-phylla forest were significantly negatively correlated with the Pielou index of the shrub layer.The Shannon-Wiener index of the tree layer in Pinus koraiensis-Abies-Picea forest was significantly positively correlated with the Simpson index of the herb layer.The Pielou index of the tree layer in Pinus koraiensis-broadleaved mixed forest,was significantly negatively correlated with the Shannon-Wiener index of the shrub layer.The Simpson index of the tree layer in the hard broad-leaved forest was significantly positively correlated with the Pielou index of the herb layer.There was a significant posi-tive correlation between Shannon-Wiener and Pielou index in shrub layer of Picea-Abies forest.Different stand spatial structure indexes have different effects on plant diversity,and the most important factor is mingling index.The higher the mingling index,the richer the diversity.Through this study,we hope to provide guidance for the diversity protection of protected areas.