Taxus wallichiana Zucc.(Himalayan yew)is subject to international and national conservation measures because of its over-exploitation and decline over the last 30 years.Predicting the impact of climate change on T.wal...Taxus wallichiana Zucc.(Himalayan yew)is subject to international and national conservation measures because of its over-exploitation and decline over the last 30 years.Predicting the impact of climate change on T.wallichiana’s distribution might help protect the wild populations and plan effective ex situ measures or cultivate successfully.Considering the complexity of climates and the uncertainty inherent in climate modeling for mountainous regions,we integrated three Representative Concentration Pathways(RCPs)(i.e.,RCP2.6,RCP4.5,RCP8.5)based on datasets from 14 Global Climate Models of Coupled Model Intercomparison Project,Phase 5 to:(1)predict the potential distribution of T.wallichiana under recent past(1960–1990,hereafter‘‘current’’)and future(2050s and 2070s)scenarios with the species distribution model MaxEnt.;and(2)quantify the climatic factors influencing the distribution.In respond to the future warming climate scenarios,(1)highly suitable areas for T.wallichiana would decrease by 31–55%at a rate of 3–7%/10a;(2)moderately suitable areas would decrease by 20–30%at a rate of 2–4%/10a;(3)the average elevation of potential suitable sites for T.wallichiana would shift upslope by 390 m(15%)to 948 m(36%)at a rate of 42–100 m/10a.Average annual temperature(contribution rate ca.61%),isothermality and temperature seasonality(20%),and annual precipitation(17%)were the main climatic variables affecting T.wallichiana habitats.Prior protected areas and suitable planting areas must be delimited from the future potential distributions,especially the intersection areas at different suitability levels.It is helpful to promote the sustainable utilization of this precious resource by prohibiting exploitation and ex situ restoring wild resources,as well as artificially planting considering climate suitability.展开更多
Plants synthesize certain phytoconstituents for their protection, which, because they are not of primary need, are known as secondary metabolites. These secondary metabolites of plants, have often been found to have m...Plants synthesize certain phytoconstituents for their protection, which, because they are not of primary need, are known as secondary metabolites. These secondary metabolites of plants, have often been found to have medicinal uses for human beings. One such gymnosperm having secondary metabolites of medicinal potential for humans is Taxus wallichiana （Himalayan yew）. Besides being the source of taxol, this plant has been investigated for its essential oil, diterpenoids, lignans, steroids, sterols and biflavonoids. Traditionally, it is used to treat disorders of the digestive, respiratory, nervous and skeletal systems. Although pharmacologically underexplored, it has been used for antiepileptic, anti-inflammatory anticancer, antipyretic, analgesic, immunomodulatory and antimicrobial activities. The present review compiles traditional uses, phytochemical constituents （specifically the secondary metabolites） pharmacological activities and the toxicity of T. wallichiana.展开更多
文摘Taxus wallichiana Zucc.(Himalayan yew)is subject to international and national conservation measures because of its over-exploitation and decline over the last 30 years.Predicting the impact of climate change on T.wallichiana’s distribution might help protect the wild populations and plan effective ex situ measures or cultivate successfully.Considering the complexity of climates and the uncertainty inherent in climate modeling for mountainous regions,we integrated three Representative Concentration Pathways(RCPs)(i.e.,RCP2.6,RCP4.5,RCP8.5)based on datasets from 14 Global Climate Models of Coupled Model Intercomparison Project,Phase 5 to:(1)predict the potential distribution of T.wallichiana under recent past(1960–1990,hereafter‘‘current’’)and future(2050s and 2070s)scenarios with the species distribution model MaxEnt.;and(2)quantify the climatic factors influencing the distribution.In respond to the future warming climate scenarios,(1)highly suitable areas for T.wallichiana would decrease by 31–55%at a rate of 3–7%/10a;(2)moderately suitable areas would decrease by 20–30%at a rate of 2–4%/10a;(3)the average elevation of potential suitable sites for T.wallichiana would shift upslope by 390 m(15%)to 948 m(36%)at a rate of 42–100 m/10a.Average annual temperature(contribution rate ca.61%),isothermality and temperature seasonality(20%),and annual precipitation(17%)were the main climatic variables affecting T.wallichiana habitats.Prior protected areas and suitable planting areas must be delimited from the future potential distributions,especially the intersection areas at different suitability levels.It is helpful to promote the sustainable utilization of this precious resource by prohibiting exploitation and ex situ restoring wild resources,as well as artificially planting considering climate suitability.
文摘Plants synthesize certain phytoconstituents for their protection, which, because they are not of primary need, are known as secondary metabolites. These secondary metabolites of plants, have often been found to have medicinal uses for human beings. One such gymnosperm having secondary metabolites of medicinal potential for humans is Taxus wallichiana （Himalayan yew）. Besides being the source of taxol, this plant has been investigated for its essential oil, diterpenoids, lignans, steroids, sterols and biflavonoids. Traditionally, it is used to treat disorders of the digestive, respiratory, nervous and skeletal systems. Although pharmacologically underexplored, it has been used for antiepileptic, anti-inflammatory anticancer, antipyretic, analgesic, immunomodulatory and antimicrobial activities. The present review compiles traditional uses, phytochemical constituents （specifically the secondary metabolites） pharmacological activities and the toxicity of T. wallichiana.
