A Study Of Community Assembly Along Gradients In North Slope Of Qinling Mountains

Community assembly is a core ecological process for maintaining biodiversity.The deterministic process based on niche theory deem that community assembly process is dominated by environmental filtering in harsh habitat or wider scale,while this process is dominated by limiting similarity in mild habitat or smaller scale.The environmental filtering process may lead to show a similar performance among co-occurring species,whereas the limiting similarity may lead to show a dissimilar phenomenon.Meanwhile,the neutral theory which do not consider these environmental factors deem that community assembly is related to geographical factors,rather than other factors.In this study area,Qinling Mountains is a high mountains which has a lot of environmental gradients.It is necessary to study community assembly along these gradients for understanding the relative role in biodiversity maintenance mechanism in this region.This study would provide evidence in plants' response to environment change.In this study,we selected Taibai Mountain,Guanshan Mountain,Guangtoushan Mountain,Wangshunshan Mountain,Qingfengxia Valley and Zhuque Park for study sites.We detected the phylogenetic structure,functional structure,phylogenetic signal among different gradients,species pools,growth types and scales.We also studied the species diversity,phylogenetic diversity,functional diversity and trait-trait trade-offs along gradients,for understanding the community assembly mechanism in this region.We found that:[1] Elevation is the main factor which dominated the assembly patterns in this region.[2] The woody species is filtered by harsh environment in high altitude area.The community structures based on phylogenetic and functional methods show inconsistent pattern in low-middle altitude area.However,the deterministic process dominated community assembly in that area.[3] The phylogenetic signal would not show significant tendency along gradients on most traits,except Hmax.The relationship between phylogeny and trait may change along environmental gradients.[4] Species among growth types may show similar patterns that response to environment factors.However,the community assembly patterns may be different among growth types.Herbaceous species has independent ecological strategies which is different to woody species.[5] The ? diversity based on phylogenetic and taxonomic methods show different patterns to functional ? diversity.Elevation and soil may influence the ? diversity patterns.Species? diversity is related to elevation and geographic distance.Woody species' community assembly is affected by environmental filtering and dispersal limitation.[6] Community assembly show different patterns among different scales.The different assembly patterns among sites at local scale is caused by different colonized history.Elevation is the main factor leading to community assembly at regional scale.Environment filter species in high altitude area.All in all,there is different performances of biodiversity and assembly patterns among different scales,species pools,growth types and environmental gradients.Using taxonomic,phylogenetic and functional methods to understand community assembly process,is a novel insight to explain biodiversity maintenance mechanism.