Vascular epiphyte diversity and the correlation analysis with host tree characteristics:A case in a mid-mountain moist evergreen broad-leaved forest,Ailao Mountains
Aims:Vascular epiphytes have a significant contribution to maintaining biodiversity,carbon storage,ecological hydrology and nutrient flux in a forest ecosystem.Assessing the diversity pattern of epiphytes thus can provide a basis for community assembly mechanism,conservation and resource utilization of epiphytes in the context of global change.In this context,we aimed to analyze the species and phylogenetic diversity including the phylogenetic structure of vascular epiphytes,and their correlations with host characteristics in the subtropical evergreen broad-leaved forest in the Ailao Mountains,Southwest China.Methods:Using a built-in canopy crane,we observed 311 individuals of dominant host trees in the 1.44 ha permanent plot and recorded the occurrence of vascular epiphytes including host tree identity,diameter at breast height(DBH)and tree height.Afterward,species richness(S),phylogenetic diversity(PD)and phylogenetic structure(net nearest taxa index(NTI)and net relatedness index(NRI))of vascular epiphytes and their correlation with DBH,height and species of host trees were evaluated.Results:A total of 62 species of vascular epiphytes belonging to 26 families and 44 genera were found.Remarkably,significant positive correlations were found between the epiphyte species richness and PD with the host DBH and height(P＜0.001).No significant correlations were detected between standard phylogenetic diversity(SES.PD)and species richness.The species richness and PD of epiphytes in Stewartia pteropetiolata were significantly lower than in other host species(P＜0.001).However,SES.PD significantly increased with the increase in host DBH(P＜0.05)and decreased with the increase in host height(P＜0.05).The phylogenetic structures of epiphytes on the Castanopsis wattii and Michelia floribunda were divergent,while epiphytes on the Lithocarpus xylocarpus and Stewartia pteropetiolata were clustered.Epiphytes on the other host trees did not show any phylogenetic structural pattern.Conclusion:Host tree characteristics,including host size and host species differences,are the key factors that maintain the diversity pattern of vascular epiphytes.These results can provide a solid foundation for future analysis of the pattern and maintenance mechanism of epiphyte diversity from multiple dimensions and perspectives.
NETL
NSTL
万方数据
