Tibetan spruce (Picea smithiana) is an endemic species of the Himalayas,and it distributes only in a re-stricted area with very low number.To address the lack of detailed distributional information,we used maximum en-...Tibetan spruce (Picea smithiana) is an endemic species of the Himalayas,and it distributes only in a re-stricted area with very low number.To address the lack of detailed distributional information,we used maximum en-tropy (Maxent) niche-based model to predict the species' potential distribution from limited occurrence-only records.The location data of P.smithiana,relative bioclimatic variables,vegetation data,digital elevation model (DEM),and the derived data were analyzed in Maxent.The receiver operating characteristic (ROC) curve was applied to assess the prediction accuracy.The Maxent jackknife test was performed to quantify the training gains from data layers and the response of P.smithiana distribution to four typical environmental variables was analyzed.Results show that the model performs well at the regional scale.There is a potential for continued expansion of P.smithiana population numbers and distribution in China.P.smithiana potentially distributes in the lower reaches of Gyirong Zangbo and Poiqu rivers in Gyirong and Nyalam counties in Qomolangma (Mount Everest) National Nature Preserve (QNNP),China.The species prefers warm temperate climate in mountain area and mainly distributes in needle-leaved evergreen closed to open forest and mixed forest along the river valley at relatively low altitudes of about 2000-3000 m.Model simulations suggest that distribution patterns of rare species with few species numbers can be well predicted by Max-ent.展开更多
Habitat evaluation constitutes an important and fundamental step in the management of wildlife populations and conservation policy planning. Geographic information system （GIS） and species presence data provide the ...Habitat evaluation constitutes an important and fundamental step in the management of wildlife populations and conservation policy planning. Geographic information system （GIS） and species presence data provide the means by which such evaluation can be done. Maximum Entropy （MaxEnt） is widely used in habitat suitability modeling due to its power of accuracy and additional descriptive properties To survey snow leopard populations in Qomolangma （Mt. Everest） National Nature Reserve （QNNR）, Xizang （Tibet）, China, we pooled 127 pugmarks, 415 scrape marks, and 127 non-invasive identifications of the animal along line transects and recorded 87 occurrences through camera traps from 2014-2017. We adopted the MaxEnt model to generate a map highlighting the extent of suitable snow leopard habitat in QNNR. Results showed that the accuracy of the MaxEnt model was excellent （mean AUC=0.921）. Precipitation in the driest quarter, ruggedness, elevation, maximum temperature of the warmest month, and annual mean temperature were the main environmental factors influencing habitat suitability for snow leopards, with contribution rates of 20.0%, 14.4%, 13.3%, 8.7%, and 8.2% respectively The suitable habitat area extended for 7 001.93 km^2, representing 22.72% of the whole reserve. The regions bordering Nepal were the main suitable snow leopard habitats and consisted of three separate habitat patches Our findings revealed that precipitation, temperature conditions, ruggedness, and elevations of around 4 000 m a.s.I, influenced snow leopard preferences at the landscape level in QNNR. We advocate further research and cooperation with Nepal to evaluate habitat connectivity and to explore possible proxies of population isolation among these patches. Furthermore, evaluation of subdivisions within the protection zones of QNNR is necessary to improve conservation strategies and enhance protection.展开更多
[Objective] The study aimed to analyze the changing characteristics of meteorological elements in Mount Qomolangma Nature Reserve.[Method] Based on the ground observation data of Nyalam and Tingri station in Mount Qom...[Objective] The study aimed to analyze the changing characteristics of meteorological elements in Mount Qomolangma Nature Reserve.[Method] Based on the ground observation data of Nyalam and Tingri station in Mount Qomolangma Nature Reserve,temperature,ground temperature,evaporation,precipitation and snow depth were analyzed.[Result] Annual average temperature of Nyalam and Tingri tended to increase since the 1960s,especially Tingri station.Annual mean ground temperature also increased since observational data was available in 1986,and was more prominent in Nyalam station,with growth rate of 0.9 ℃/10 a during recent 25 years.Average temperature in cold and warm season showed an increasing trend,but average temperature in cold season rose more fastly than that of warm season.There was a regional difference in annual average precipitation and evaporation.That is,annual average precipitation and evaporation of Tingri station enhanced since the early 1980s,but those of Nyalam station decreased slightly since the late 1980s.Annual snow depth in the two stations showed decreasing trend,but the variation of snow depth in Nyalam station was greater,that is,the snow depth increased from the 1960s to the late 1980s,while decreased since the 1990s.[Conclusion] The research could provide scientific references for the protection of ecological environment in Mount Qomolangma Nature Reserve in future.展开更多
基金Under the auspices of National Basic Research Program of China (No.2010CB951704)Institutional Consolidation for Coordinated and Integrated Monitoring of Natural Resources towards Sustainable Development and Environmental Conservation in the Hindu Kush-Karakoram-Himalaya Mountain Complex (No.76444-000)External Cooperation Program of Chinese Academy of Sciences (No.GJHZ0954)
文摘Tibetan spruce (Picea smithiana) is an endemic species of the Himalayas,and it distributes only in a re-stricted area with very low number.To address the lack of detailed distributional information,we used maximum en-tropy (Maxent) niche-based model to predict the species' potential distribution from limited occurrence-only records.The location data of P.smithiana,relative bioclimatic variables,vegetation data,digital elevation model (DEM),and the derived data were analyzed in Maxent.The receiver operating characteristic (ROC) curve was applied to assess the prediction accuracy.The Maxent jackknife test was performed to quantify the training gains from data layers and the response of P.smithiana distribution to four typical environmental variables was analyzed.Results show that the model performs well at the regional scale.There is a potential for continued expansion of P.smithiana population numbers and distribution in China.P.smithiana potentially distributes in the lower reaches of Gyirong Zangbo and Poiqu rivers in Gyirong and Nyalam counties in Qomolangma (Mount Everest) National Nature Preserve (QNNP),China.The species prefers warm temperate climate in mountain area and mainly distributes in needle-leaved evergreen closed to open forest and mixed forest along the river valley at relatively low altitudes of about 2000-3000 m.Model simulations suggest that distribution patterns of rare species with few species numbers can be well predicted by Max-ent.
基金funded primarily by the Everest Snow Leopard Conservation Center,a partnership initiative of Vanke Foundation and Qomolangma National Nature Reserve Administration
文摘Habitat evaluation constitutes an important and fundamental step in the management of wildlife populations and conservation policy planning. Geographic information system （GIS） and species presence data provide the means by which such evaluation can be done. Maximum Entropy （MaxEnt） is widely used in habitat suitability modeling due to its power of accuracy and additional descriptive properties To survey snow leopard populations in Qomolangma （Mt. Everest） National Nature Reserve （QNNR）, Xizang （Tibet）, China, we pooled 127 pugmarks, 415 scrape marks, and 127 non-invasive identifications of the animal along line transects and recorded 87 occurrences through camera traps from 2014-2017. We adopted the MaxEnt model to generate a map highlighting the extent of suitable snow leopard habitat in QNNR. Results showed that the accuracy of the MaxEnt model was excellent （mean AUC=0.921）. Precipitation in the driest quarter, ruggedness, elevation, maximum temperature of the warmest month, and annual mean temperature were the main environmental factors influencing habitat suitability for snow leopards, with contribution rates of 20.0%, 14.4%, 13.3%, 8.7%, and 8.2% respectively The suitable habitat area extended for 7 001.93 km^2, representing 22.72% of the whole reserve. The regions bordering Nepal were the main suitable snow leopard habitats and consisted of three separate habitat patches Our findings revealed that precipitation, temperature conditions, ruggedness, and elevations of around 4 000 m a.s.I, influenced snow leopard preferences at the landscape level in QNNR. We advocate further research and cooperation with Nepal to evaluate habitat connectivity and to explore possible proxies of population isolation among these patches. Furthermore, evaluation of subdivisions within the protection zones of QNNR is necessary to improve conservation strategies and enhance protection.
文摘[Objective] The study aimed to analyze the changing characteristics of meteorological elements in Mount Qomolangma Nature Reserve.[Method] Based on the ground observation data of Nyalam and Tingri station in Mount Qomolangma Nature Reserve,temperature,ground temperature,evaporation,precipitation and snow depth were analyzed.[Result] Annual average temperature of Nyalam and Tingri tended to increase since the 1960s,especially Tingri station.Annual mean ground temperature also increased since observational data was available in 1986,and was more prominent in Nyalam station,with growth rate of 0.9 ℃/10 a during recent 25 years.Average temperature in cold and warm season showed an increasing trend,but average temperature in cold season rose more fastly than that of warm season.There was a regional difference in annual average precipitation and evaporation.That is,annual average precipitation and evaporation of Tingri station enhanced since the early 1980s,but those of Nyalam station decreased slightly since the late 1980s.Annual snow depth in the two stations showed decreasing trend,but the variation of snow depth in Nyalam station was greater,that is,the snow depth increased from the 1960s to the late 1980s,while decreased since the 1990s.[Conclusion] The research could provide scientific references for the protection of ecological environment in Mount Qomolangma Nature Reserve in future.
