Origins and evolution of plant diversity in the Hengduan Mountains, China

1.Introduction The Hengduan Mountains region(HDM)in southwest China,one of the earth's 34 biodiversity hotspots,is characterized by its unique geology,dramatic topography,a climate where snow and below freezing temperatures can occur on any day of the year,by its location at elevations averaging between(1400e)2000 and4500(e5300)meters above sea level(m a.s.l.),and by one of

Phosphorus Biogeochemical Cycle Research in Mountainous Ecosystems

Phosphorus(P),as a limiting nutrient,plays a crucial role in the mountainous ecosystem development.Its biogeochemical cycle in mountainous ecosystems determines the bioavailability and sustainable supply of P,and thus becomes a crucial process which needs to be fully understood and described for ecological and environmental conservation.However,most of research about P biogeochemical processes has been carried out in aquatic environment and agronomic field,but rare researches have been done in mountain ecosystem.In the present review,we summarize researches on P biogeochemical cycle concerning mountain ecosystem in recent decades,including rock weathering,the release,transformation and bioavailability of P,interactions between the P biological cycle and microbial and plant life,as well as the development of models.Based on the state of art,we propose the future work on this direction,including the integration of all these research,the development of a practical model to understand the P biogeochemical cycle and its bioavailability,and to provide a reference for ecological and environmental conservation of mountainous ecosystems and lowland aquatic systems.

Phylogenetic conservatism in threatened species responses to climate change differs between functional types in the Gongga Mountains of China

Climate change has become one of the most critical threats to global biodiversity.However,whether phylogenetically related species respond to climate change in similar ways remains controversial.The answer to this question is crucial for understanding the impacts of climate change and the conservation on the tree of life.By integrating species distribution models with a molecular phylogeny of 50 threatened plant species from one of the global biodiversity hotspots,Gongga Mountains(Mt.Gongga)in southwest China,we evaluated the responses of threatened plant species to future climate change,and estimated whether species responses are phylogenetically conserved.Phylogenetic reconstruction was used to calculate the phylogenetic distance and null model to verify the reliability of the results.We found that correlations between responses of different species to future climate change decreased with the increase in their phylogenetic distance in the monocotyledonous or herbaceous species,but not in the dicotyledonous and woody species.Our results suggested that the responses of herbaceous and monocotyledonous threatened species in Mt.Gongga to future climate change tend to be phylogenetically conserved,while the responses of woody and dicotyledonous threatened species are not.Our study provides evidence for the existence of phylogenetically non-random extinction in the monocotyledonous herbs in Mt.Gongga and highlights the importance of integrating phylogenetic information and evolutionary history into conservation planning.We also provide theoretical basis and technical support for designing effective conservation schemes for the protection of biodiversity under anthropogenic climate change.