<div style="text-align:justify;"> With global warming and increased human activity, more and more ground surface areas have been affected, which leads to the creation of many problems. To understand th...<div style="text-align:justify;"> With global warming and increased human activity, more and more ground surface areas have been affected, which leads to the creation of many problems. To understand the ecological environment changes in a typical alpine region, information on landcovers changes in the study area from 2000 to 2020 was obtained by combining remote sensing, geographic information system, and traditional statistical analysis for the Sanjiangyuan National Nature Reserve on the Qinghai-Tibet Plateau, China. The results show that the changes of surface cover in Sanjiangyuan National Nature Reserve are relatively concentrated, mainly distributed in the sections of south, northwest, central, and northeast, with the area of the changed regions and the unchanged regions being 31,127.45 km<sup>2</sup> and 271,941.37 km<sup>2</sup>, respectively. The transformation between the various types of ground landcover is mainly characterized by a shift from other types to grassland and from grassland to bare land. And the regions of change are mostly concentrated between 3500 - 4600 m in elevation. </div>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
The forest community diversity along the altitudinal gradient was analyzed in the Cibagou National Nature Reserve. Results showed that the forest types of Cibagou Gorge could be divided into six types: Castanopsis hys...The forest community diversity along the altitudinal gradient was analyzed in the Cibagou National Nature Reserve. Results showed that the forest types of Cibagou Gorge could be divided into six types: Castanopsis hystrix forest;camphor and acer mixed forest, blue Japanese oak broad-leaved mixed forest, blue Japanese oak forest, Populus simonii mixed forest;Quercus aquifolioides forest. The total coverage of undergrowth vegetation altitude was the lowest at 1749 m, only 30%, and plant species numbers in the sample was only 5. The total coverage of the plant was the highest at 2327 m altitude, the value was 95%, and the number of species in experiment plot was 14. The species richness of Margalef increased first and then decreased with the increase of altitude gradient at 1749 m to 2880 m, and the Shannon-wiener species diversity index increased, but the difference was not significant, Pielou species evenness and Sheldon species evenness index decreased first and then increased with altitude.展开更多
文摘<div style="text-align:justify;"> With global warming and increased human activity, more and more ground surface areas have been affected, which leads to the creation of many problems. To understand the ecological environment changes in a typical alpine region, information on landcovers changes in the study area from 2000 to 2020 was obtained by combining remote sensing, geographic information system, and traditional statistical analysis for the Sanjiangyuan National Nature Reserve on the Qinghai-Tibet Plateau, China. The results show that the changes of surface cover in Sanjiangyuan National Nature Reserve are relatively concentrated, mainly distributed in the sections of south, northwest, central, and northeast, with the area of the changed regions and the unchanged regions being 31,127.45 km<sup>2</sup> and 271,941.37 km<sup>2</sup>, respectively. The transformation between the various types of ground landcover is mainly characterized by a shift from other types to grassland and from grassland to bare land. And the regions of change are mostly concentrated between 3500 - 4600 m in elevation. </div>
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The forest community diversity along the altitudinal gradient was analyzed in the Cibagou National Nature Reserve. Results showed that the forest types of Cibagou Gorge could be divided into six types: Castanopsis hystrix forest;camphor and acer mixed forest, blue Japanese oak broad-leaved mixed forest, blue Japanese oak forest, Populus simonii mixed forest;Quercus aquifolioides forest. The total coverage of undergrowth vegetation altitude was the lowest at 1749 m, only 30%, and plant species numbers in the sample was only 5. The total coverage of the plant was the highest at 2327 m altitude, the value was 95%, and the number of species in experiment plot was 14. The species richness of Margalef increased first and then decreased with the increase of altitude gradient at 1749 m to 2880 m, and the Shannon-wiener species diversity index increased, but the difference was not significant, Pielou species evenness and Sheldon species evenness index decreased first and then increased with altitude.
