A new mamenchisaurid dinosaur, Eomamenchisaurus yuanmouensis gen et sp. nov. is erected based on an incomplete skeleton from the Zhanghe Formation, the Middle Jurassic of Yuanmou, Yunnan Province. The new taxon is cha...A new mamenchisaurid dinosaur, Eomamenchisaurus yuanmouensis gen et sp. nov. is erected based on an incomplete skeleton from the Zhanghe Formation, the Middle Jurassic of Yuanmou, Yunnan Province. The new taxon is characterized by absence of pleurocoels in dorsal vertebrae and the dorsal verterbrae with slightly convex anterior articular surfaces, moderately concave posterior articular surfaces; the fourth trochanter is developed posteromedially on the femur; length ratio of the tibia to the femur is approximately 0.64; and the shaft of the ischium is rod-like. Two fused centra of the posterior dorsal vertebrae (the presumed 9th and the 10th dorsal vertebrae) are similar to those in other mamenchisaurid dinosaurs, including Mamenchisaurus hochuanesis, M. youngi and Chuanjiesaurus anaensis. Therefore, fusion of centra of the ninth and the tenth dorsal vertebrae can be recognized as a synapomorphic character of the Mamenchisauridae.展开更多
The tropic region of Yunnan is a treasurable land with rich resources and great development potentials. The natural environment and resources of the region are characterized by a complicated topography, great height d...The tropic region of Yunnan is a treasurable land with rich resources and great development potentials. The natural environment and resources of the region are characterized by a complicated topography, great height deviation, monsoon climate as well as abound biological resources. Therefore, the tropic region becomes an ideal place for developing agricultural production base, though it do exist such problems as adverse location, sparsely distributed land resources, poor traffic conditions and deterioration of ecological environment. In order to further exploit the tropical resources and to implement comprehensive harnessing, we should take the following countermeasures:Working out a comprehensive development planning; restoring ecological environment,establishing agricultural production base; tapping fully water resources; constructing the traffic line and developing the border ports and tourism spots.展开更多
Yuanmousaurusjiangyiensis gen. et sp. nov. is erected based on an incomplete skeleton. It is characterized by more complex structures of the neural arches in the dorsal vertebrae than those in Omeisaurus, but less com...Yuanmousaurusjiangyiensis gen. et sp. nov. is erected based on an incomplete skeleton. It is characterized by more complex structures of the neural arches in the dorsal vertebrae than those in Omeisaurus, but less complex than those of Euhelopus; the dorsal vertebra bears 9 laminae, forming three cavities on the lateral surface of the neural arch; the dorsal vertebral neural spines with dorsoventrally-oriented cavities are similar to those of Omeisaurus and Patagosaurus. Yuanmousaurus is more primitive than Euhelopus, but more derived than Omeisaurus. The similar dorsal vertebral structure between Yuanmousaurus and Patagosaurus may indicate that they have a close relationship to each other.展开更多
Supported by RS and GIS, the land use change from 1982 to 2003 were analyzed and the impacts of land use changes on pH value, organic matter, total N, total P, total K, available N, available P, and available K in soi...Supported by RS and GIS, the land use change from 1982 to 2003 were analyzed and the impacts of land use changes on pH value, organic matter, total N, total P, total K, available N, available P, and available K in soil of Xiaojiang watershed, a typical karst agricultural region of Yunnan Province, Southwest China were assessed. The following aspects are concluded. (1) The total land use converted during the past 20 years in Xiaojiang watershed covers an area of 610.12 km^2, of which 134.29 km^2 of forestland was converted into cultivated land, and 210 km^2 of.unused land was converted into cultivated land. (2) The rapid growth of population and the economic development were the main driving forces of land use change. (3) With the change in land use, the soil properties have been changed significantly. The pH, organic matter, total N, total P, total K, available N, available P and available K in soil in 1982 were 6.3, 38.02 g·kg^-1, 1.86 g·kg^-1, 1.63 g·kg^-1, 10.94 g·kg^-1, 114.42 g·kg^-1, 11.65 mg·kg^-1 and 64.69 mg·kg^-1g, respectively; and those in 2003 were 6.73, 25.26 g·kg^-1, 1.41 g·kg^-1, 0.99 g·kg^-1, 12.6 g·kg^-1, 113.43 mg·kg^-1, 11.11 mg·kg^-1 and 151.59 mg·kg^-1, respectively. Pared samples t-test of the tested indices of soil properties indicate that those indices have changed significantly during the last 20 years. But the soil properties changed differently, due to the differences in land use change. (4) Also, with the change in land use and management measures of soil, the modifications in soil properties which developed from carbonate rocks were more sensitive than those in the soil developed from sandstone.展开更多
The data of short-period (1~18 s) surface waves recorded by 23 stations belonging to the digital seismic network of Yunnan Province of China are used in this paper. From these data, the dispersion curves of phase velo...The data of short-period (1~18 s) surface waves recorded by 23 stations belonging to the digital seismic network of Yunnan Province of China are used in this paper. From these data, the dispersion curves of phase velocities of the fundamental mode Rayleigh wave along 209 paths are determined by using the two-station narrowband filtering cross-correlation method. Adopting tomography method, the distribution maps of phase velocities at various peri-ods in Yunnan region are inverted. The maps of phase velocities on profiles along 24N, 25N, 26N, 27N and 100.5E and the distribution maps of phase velocities at 3 periods in the study region are given. The results show that the phase velocity distribution in Yunnan region has strong variations in horizontal direction, and the phase velocity distribution in short-period range is closely related to the thickness of sedimentary layers in the shallow crust. The phase velocity in southern part of the Sichuan-Yunnan rhombic block encircled by the Honghe fault and Xiaojiang fault is obviously lower than that in surrounding areas. The epicentral locations of strong earthquakes in Yunnan region are mainly distributed in transitional zones between low and high phase velocities.展开更多
This paper illustrates the illegal trade of wild animals in China from 1996 to 2014 by referring to previously reported references and data. There have been83 species(22 families, 8 orders) of wild mammals illegally...This paper illustrates the illegal trade of wild animals in China from 1996 to 2014 by referring to previously reported references and data. There have been83 species(22 families, 8 orders) of wild mammals illegally traded and smuggled in China, mainly found in the southwest border, especially in Yunnan and Guangxi.Smuggling has seriously affected the ecological security of China, so it is necessary to intensify efforts to fight such crime, and enhance the people’s awareness of wildlife protection.展开更多
Background:Regional ecosystem health assessments are the basis for the sustainable development of society.However,an ecosystem is a complex integration of ecosystem mosaics and subsystems that influence each other,mak...Background:Regional ecosystem health assessments are the basis for the sustainable development of society.However,an ecosystem is a complex integration of ecosystem mosaics and subsystems that influence each other,making it difficult to evaluate them using traditional assessment methods of linear and explicit functions.We introduce a back-propagation neural network model optimized by a genetic algorithm to evaluate ecosystem health in 16 districts in Yunnan Province.Result:(1)The model required fewer inputs to evaluate complex and nonlinear systems,avoided the need for subjective weights,and performed well in this practical application to regional ecosystem health assessment.(2)The ecosystem health in Yunnan Province was increasing,and there was a significant positive spatial autocorrelation during 2000-2020,showing that districts with high Ecosystem Health cluster together and the ecological protection policy of the region has produced a diffusion effect,leading to continuous improvement of the ecological health of the surrounding areas.High-low outlier areas of ecosystem health should be paid more attention,because of the increasing instability of local health levels.Conclusion:This study provides a methodological exploration for assessing spatial mosaics of different ecosystems at a regional scale.展开更多
Following climate change,changes in precipitation patterns and food security are major challenges faced by humans.However,research on how these changes in precipitation pattern impacts food supply is limited.This stud...Following climate change,changes in precipitation patterns and food security are major challenges faced by humans.However,research on how these changes in precipitation pattern impacts food supply is limited.This study aims to elucidate this impact and response mechanisms using precipitation data of a climate change-sensitive confluence zone of the southwest and southeast monsoons in Yunnan Province from 1988 to 2018.The results revealed that the precipitation pattern could be divided into three periods:abundant precipitation(Stage I,from 1988 to 2004),decreased precipitation(Stage II,from 2005 to 2015),and drought recovery(Stage III,from 2016 to 2018).Following the transition from Stage I to Stage II and from Stage II to Stage III,the area of precipitation changed significantly,accounting for 15.07%,13.87%,and 16.53%of Yunnan’s total area,for Stages I,II,and III,respectively.At the provincial level,a significant positive correlation was observed between precipitation and food production(r=0.535,P<0.01),and the correlation coefficient between precipitation and grain yield was higher than that between precipitation and meat and milk production.Based on a precipitation–grain yield transect and breakpoint detection method,key precipitation thresholds affecting grain yield were estimated as 700 and 1500 mm,respectively;when precipitation was<700,700–1500,and≥1500 mm,the correlation coefficients between precipitation and grain yield were 0.448(P<0.01),0.370(P<0.01),and–0.229(P>0.05),respectively.Based on the precipitation thresholds,Yunnan Province can be divided into precipitation surplus,precipitation equilibrium,and precipitation deficit regions,corresponding countermeasures to stabilize grain yield were proposed for each of these regions.The threshold effect of precipitation on grain yield is controlled by molecular-level water–crop mechanisms,in which reactive oxygen species,a by-product of plant aerobic metabolism,plays a key regulatory role.展开更多
文摘A new mamenchisaurid dinosaur, Eomamenchisaurus yuanmouensis gen et sp. nov. is erected based on an incomplete skeleton from the Zhanghe Formation, the Middle Jurassic of Yuanmou, Yunnan Province. The new taxon is characterized by absence of pleurocoels in dorsal vertebrae and the dorsal verterbrae with slightly convex anterior articular surfaces, moderately concave posterior articular surfaces; the fourth trochanter is developed posteromedially on the femur; length ratio of the tibia to the femur is approximately 0.64; and the shaft of the ischium is rod-like. Two fused centra of the posterior dorsal vertebrae (the presumed 9th and the 10th dorsal vertebrae) are similar to those in other mamenchisaurid dinosaurs, including Mamenchisaurus hochuanesis, M. youngi and Chuanjiesaurus anaensis. Therefore, fusion of centra of the ninth and the tenth dorsal vertebrae can be recognized as a synapomorphic character of the Mamenchisauridae.
文摘The tropic region of Yunnan is a treasurable land with rich resources and great development potentials. The natural environment and resources of the region are characterized by a complicated topography, great height deviation, monsoon climate as well as abound biological resources. Therefore, the tropic region becomes an ideal place for developing agricultural production base, though it do exist such problems as adverse location, sparsely distributed land resources, poor traffic conditions and deterioration of ecological environment. In order to further exploit the tropical resources and to implement comprehensive harnessing, we should take the following countermeasures:Working out a comprehensive development planning; restoring ecological environment,establishing agricultural production base; tapping fully water resources; constructing the traffic line and developing the border ports and tourism spots.
文摘Yuanmousaurusjiangyiensis gen. et sp. nov. is erected based on an incomplete skeleton. It is characterized by more complex structures of the neural arches in the dorsal vertebrae than those in Omeisaurus, but less complex than those of Euhelopus; the dorsal vertebra bears 9 laminae, forming three cavities on the lateral surface of the neural arch; the dorsal vertebral neural spines with dorsoventrally-oriented cavities are similar to those of Omeisaurus and Patagosaurus. Yuanmousaurus is more primitive than Euhelopus, but more derived than Omeisaurus. The similar dorsal vertebral structure between Yuanmousaurus and Patagosaurus may indicate that they have a close relationship to each other.
基金The open foundation of physical geography of Southwest University, No.250-411109 Foundation of Science and Technology Committee of Chongqing, No.20027534+1 种基金 No.20048258 Project of Ministry of Land and Resources, No.200310400024
文摘Supported by RS and GIS, the land use change from 1982 to 2003 were analyzed and the impacts of land use changes on pH value, organic matter, total N, total P, total K, available N, available P, and available K in soil of Xiaojiang watershed, a typical karst agricultural region of Yunnan Province, Southwest China were assessed. The following aspects are concluded. (1) The total land use converted during the past 20 years in Xiaojiang watershed covers an area of 610.12 km^2, of which 134.29 km^2 of forestland was converted into cultivated land, and 210 km^2 of.unused land was converted into cultivated land. (2) The rapid growth of population and the economic development were the main driving forces of land use change. (3) With the change in land use, the soil properties have been changed significantly. The pH, organic matter, total N, total P, total K, available N, available P and available K in soil in 1982 were 6.3, 38.02 g·kg^-1, 1.86 g·kg^-1, 1.63 g·kg^-1, 10.94 g·kg^-1, 114.42 g·kg^-1, 11.65 mg·kg^-1 and 64.69 mg·kg^-1g, respectively; and those in 2003 were 6.73, 25.26 g·kg^-1, 1.41 g·kg^-1, 0.99 g·kg^-1, 12.6 g·kg^-1, 113.43 mg·kg^-1, 11.11 mg·kg^-1 and 151.59 mg·kg^-1, respectively. Pared samples t-test of the tested indices of soil properties indicate that those indices have changed significantly during the last 20 years. But the soil properties changed differently, due to the differences in land use change. (4) Also, with the change in land use and management measures of soil, the modifications in soil properties which developed from carbonate rocks were more sensitive than those in the soil developed from sandstone.
基金Joint Seismological Science Foundation of China (101086) and the key project Digital Crustal and Mantle Structure of Chinese Mainland from China Earthquake Administration.
基金Joint Seismological Science Foundation of China (101086) and the key project "Digital Crustal and Mantle Structure of Chinese Mainland" from China Earthquake Administration.
文摘The data of short-period (1~18 s) surface waves recorded by 23 stations belonging to the digital seismic network of Yunnan Province of China are used in this paper. From these data, the dispersion curves of phase velocities of the fundamental mode Rayleigh wave along 209 paths are determined by using the two-station narrowband filtering cross-correlation method. Adopting tomography method, the distribution maps of phase velocities at various peri-ods in Yunnan region are inverted. The maps of phase velocities on profiles along 24N, 25N, 26N, 27N and 100.5E and the distribution maps of phase velocities at 3 periods in the study region are given. The results show that the phase velocity distribution in Yunnan region has strong variations in horizontal direction, and the phase velocity distribution in short-period range is closely related to the thickness of sedimentary layers in the shallow crust. The phase velocity in southern part of the Sichuan-Yunnan rhombic block encircled by the Honghe fault and Xiaojiang fault is obviously lower than that in surrounding areas. The epicentral locations of strong earthquakes in Yunnan region are mainly distributed in transitional zones between low and high phase velocities.
基金Supported by National Natural Science Foundation of China(31470570)Natural Science Foundation of Chongqing(cstc2014jcyj A80013)+1 种基金Science Foundation of Chongqing Education Commission(kj1400534)Chongqing Creative Program for Graduate Students(CYS15155)~~
文摘This paper illustrates the illegal trade of wild animals in China from 1996 to 2014 by referring to previously reported references and data. There have been83 species(22 families, 8 orders) of wild mammals illegally traded and smuggled in China, mainly found in the southwest border, especially in Yunnan and Guangxi.Smuggling has seriously affected the ecological security of China, so it is necessary to intensify efforts to fight such crime, and enhance the people’s awareness of wildlife protection.
基金This work was supported by the National Natural Science Foundation of China[52078160]。
文摘Background:Regional ecosystem health assessments are the basis for the sustainable development of society.However,an ecosystem is a complex integration of ecosystem mosaics and subsystems that influence each other,making it difficult to evaluate them using traditional assessment methods of linear and explicit functions.We introduce a back-propagation neural network model optimized by a genetic algorithm to evaluate ecosystem health in 16 districts in Yunnan Province.Result:(1)The model required fewer inputs to evaluate complex and nonlinear systems,avoided the need for subjective weights,and performed well in this practical application to regional ecosystem health assessment.(2)The ecosystem health in Yunnan Province was increasing,and there was a significant positive spatial autocorrelation during 2000-2020,showing that districts with high Ecosystem Health cluster together and the ecological protection policy of the region has produced a diffusion effect,leading to continuous improvement of the ecological health of the surrounding areas.High-low outlier areas of ecosystem health should be paid more attention,because of the increasing instability of local health levels.Conclusion:This study provides a methodological exploration for assessing spatial mosaics of different ecosystems at a regional scale.
基金National Key Research and Development Program of China,No.2018YFE0184300National Natural Science Foundation of China,No.41761115,No.41271203Key Research Projects of Graduate Students in Yunnan Normal University,No.ysdyjs2019166。
文摘Following climate change,changes in precipitation patterns and food security are major challenges faced by humans.However,research on how these changes in precipitation pattern impacts food supply is limited.This study aims to elucidate this impact and response mechanisms using precipitation data of a climate change-sensitive confluence zone of the southwest and southeast monsoons in Yunnan Province from 1988 to 2018.The results revealed that the precipitation pattern could be divided into three periods:abundant precipitation(Stage I,from 1988 to 2004),decreased precipitation(Stage II,from 2005 to 2015),and drought recovery(Stage III,from 2016 to 2018).Following the transition from Stage I to Stage II and from Stage II to Stage III,the area of precipitation changed significantly,accounting for 15.07%,13.87%,and 16.53%of Yunnan’s total area,for Stages I,II,and III,respectively.At the provincial level,a significant positive correlation was observed between precipitation and food production(r=0.535,P<0.01),and the correlation coefficient between precipitation and grain yield was higher than that between precipitation and meat and milk production.Based on a precipitation–grain yield transect and breakpoint detection method,key precipitation thresholds affecting grain yield were estimated as 700 and 1500 mm,respectively;when precipitation was<700,700–1500,and≥1500 mm,the correlation coefficients between precipitation and grain yield were 0.448(P<0.01),0.370(P<0.01),and–0.229(P>0.05),respectively.Based on the precipitation thresholds,Yunnan Province can be divided into precipitation surplus,precipitation equilibrium,and precipitation deficit regions,corresponding countermeasures to stabilize grain yield were proposed for each of these regions.The threshold effect of precipitation on grain yield is controlled by molecular-level water–crop mechanisms,in which reactive oxygen species,a by-product of plant aerobic metabolism,plays a key regulatory role.