茂兰喀斯特森林不同地形木本植物物种多样性和系统发育多样性OA

To study the variations of phylogenetic diversity and species diversity of woody plant communities in Karst areas under different terrains and their influencing factors,woody plants in different terrains within the Maolan Dynamic Plot of Karst Forest Eco-system in South China were selected as the research objects.Utilizing the hierarchical partitioning(HP)method and Pearson correlation analysis,it examined the changing trends of diversity indices under different terrains(depression,valley,hillside,saddle,ridge and summit),the key terrain factors driving the diversity indices,and the interrelationship between species diversity and phylogenetic diversity.The results demonstrate that:1)There is a significant difference in the community species richness index between depressions and saddles(P＜0.05),while there is no significant difference in the community Pielou evenness index and Simpson dominance index among the six terrains.The Faith's phylogenetic diversity index and the mean nearest taxon phylogenetic distance show significant differences between depressions and saddles.The mean pair phylogenetic distance shows a significant difference between hillsides and depressions,valleys.2)The relative influence of aspect on the diversity indices is the largest and plays a leading role,followed by slope,and the influence of four topographic factors on the diversity indices is not significant.3)Species richness index is significantly positively correlated with Faith's phylogenetic diversity index(P＜0.000 1),significantly negatively correlated with mean nearest taxon phylogenetic distance and Simpson dominance index.Faith's phylogenetic diversity index is significantly negatively correlated with mean nearest taxon phylogenetic distance.This study reveals that different terrains in the Maolan Karst area have different effects on species diversity and phylogenetic diversity,and the correlation between species diversity and phylogenetic diversity is not high.The aspect and slope jointly drive the variations of species diversity and phylogenetic diversity.