Alluvial fans possess diverse geomorphological features and have a significant impact on soil characteristics and variations in ecological stoichiometry.However,it remains unclear how alluvial fans in arid mountainous...Alluvial fans possess diverse geomorphological features and have a significant impact on soil characteristics and variations in ecological stoichiometry.However,it remains unclear how alluvial fans in arid mountainous areas influence the changes in ecological chemical stoichiometry and,consequently,indirectly affect ecosystem function.Alluvial fan,with its diverse topographical features,exerts a multifaceted influence on soil formation and characteristics.Limited information exists regarding the ecological stoichiometric characteristics of the alluvial fan in arid mountainous areas.This study investigated the soil physical-chemical characteristics,enzyme activities,soil ecological stoichiometries,and its driving factors of four types of micro-topographies(alluvial mesas,high floodplain,groove beach,and striated groove)in the foothills of eastern Helan Mountains,China.Results showed that soil physical and chemical properties in the 0–20 cm soil depth was consistently higher than those in the 20–40 cm soil depth,with no changes in pH,total nitrogen,and total potassium.C:P and N:P ratios in alluvial mesas,high floodplain,and striated groove were significantly higher than those in groove beach.Redundancy analysis showed that soil nutrients played the most significant role in the variation of soil ecological stoichiometry characteristics.Topography influenced soil stoichiometry indirectly,primarily through impacts on enzyme activity and soil nutrient elements.These findings elucidate the intricate interplay between soil ecological stoichiometric characteristics and environmental factors across diverse micro-topographies in alluvial fan,contributing to our understanding of the formation and development of soil in dryland.展开更多
It is of great significance to study the effects of desert plants on soil enzyme activities and soil organic carbon(SOC)for maintaining the stability of the desert ecosystem.In this study,we studied the responses of s...It is of great significance to study the effects of desert plants on soil enzyme activities and soil organic carbon(SOC)for maintaining the stability of the desert ecosystem.In this study,we studied the responses of soil enzyme activities and SOC fractions(particulate organic carbon(POC)and mineral-associated organic carbon(MAOC))to five typical desert plant communities(Convolvulus tragacanthoides,Ephedra rhytidosperma,Stipa breviflora,Stipa tianschanica var.gobica,and Salsola laricifolia communities)in the proluvial fan in the eastern foothills of the Helan Mountain in Ningxia Hui Autonomous Region,China.We recorded the plant community information mainly including the plant coverage and herb and shrub species,and obtained the aboveground biomass and plant species diversity through sample surveys in late July 2023.Soil samples were also collected at depths of 0–10 cm(topsoil)and 10–20 cm(subsoil)to determine the soil physicochemical properties and enzyme activities.The results showed that the plant coverage and aboveground biomass of S.laricifolia community were significantly higher than those of C.tragacanthoides,S.breviflora,and S.tianschanica var.gobica communities(P<0.05).Soil enzyme activities varied among different plant communities.In the topsoil,the enzyme activities of alkaline phosphatase(ALP)andβ-1,4-glucosidas(βG)were significantly higher in E.rhytidosperma and S.tianschanica var.gobica communities than in other plant communities(P<0.05).The topsoil had higher POC and MAOC contents than the subsoil.Specifically,the content of POC in the topsoil was 18.17%–42.73%higher than that in the subsoil.The structural equation model(SEM)indicated that plant species diversity,soil pH,and soil water content(SWC)were the main factors influencing POC and MAOC.The soil pH inhibited the formation of POC and promoted the formation of MAOC.Conversely,SWC stimulated POC production and hindered MAOC formation.Our study aimed to gain insight into the effects of desert plant communities on soil enzyme activities and SOC fractions,as well as the drivers of SOC fractions in the proluvial fan in the eastern foothills of the Helan Mountain and other desert ecosystems.展开更多
为了研究旅游经济发展与生态环境系统之间的空间错位程度,定量分析其空间错位关系,以宁夏为研究对象,基于空间错位理论与模型,综合利用熵权法、TOPSIS(Technique for order prefer⁃ence by similarity to ideal solution)模型、重力模...为了研究旅游经济发展与生态环境系统之间的空间错位程度,定量分析其空间错位关系,以宁夏为研究对象,基于空间错位理论与模型,综合利用熵权法、TOPSIS(Technique for order prefer⁃ence by similarity to ideal solution)模型、重力模型以及ArcGIS空间可视化表达方法对研究区2011-2018年旅游经济与生态环境系统空间错位程度进行综合分析。结果表明:2011-2018年宁夏旅游经济发展水平与生态环境发展水平分别由0.2868和0.2395增加至0.4716和0.3525,旅游经济实力不断提升,生态环境质量不断改善;从重心转移来看,旅游经济系统重心转移差异不大,而生态环境由南向北发生转移趋势,且两者之间存在比较明显的空间异质性特征;从空间错位程度来看,研究区各地市空间错位程度均较高,且呈现逐年增加的态势。整体来看,宁夏旅游经济与生态环境系统空间错位主要是因旅游区位和旅游资源差异造成的,各地市应结合自身特点,发挥资源优势,挖掘潜力,通过采取差异化的空间矫正策略达到区域旅游产业协调可持续发展的目标。展开更多
Ningxia lies in the midland of China, along the upper and middle of the Yellow River.The south of the region belongs to the Loess Plateau and the north of it is Part of theMongolian plateau. The main feature of the cl...Ningxia lies in the midland of China, along the upper and middle of the Yellow River.The south of the region belongs to the Loess Plateau and the north of it is Part of theMongolian plateau. The main feature of the climate in the whole region is dry or half dry.The ecological enviroment is in a very delicate state and human activities have made itworse. The severe consequences are widely-spread various types of ecological disasters.展开更多
While Yinchuan is not a typical city in China,the process by which its environment,culture and policies have affected its development is typical.The process of urban expansion in Yinchuan reflects the urban developmen...While Yinchuan is not a typical city in China,the process by which its environment,culture and policies have affected its development is typical.The process of urban expansion in Yinchuan reflects the urban development of China in general (or a mirror can reflect China’s development history and policies evolution).Industrial development,local policy orientation,the natural environment,and other factors have both accelerated and restrained the direction and rate of expansion experienced by Yinchuan.The future urban development of Yinchuan can be conducted from three perspectives,including its city planning,and from regional and international perspectives.These perspectives should be applied to encourage city betterment and ecological restoration,new-type urbanization and rural revitalization,regional coordination and cooperation,healthy,livable,intelligent development,and a culturally inclusive atmosphere.展开更多
Spatial models are effective in obtaining local details on grassland biomass,and their accuracy has important practical significance for the stable management of grasses and livestock.To this end,the present study uti...Spatial models are effective in obtaining local details on grassland biomass,and their accuracy has important practical significance for the stable management of grasses and livestock.To this end,the present study utilized measured quadrat data of grass yield across different regions in the main growing season of temperate grasslands in Ningxia of China(August 2020),combined with hydrometeorology,elevation,net primary productivity(NPP),and other auxiliary data over the same period.Accordingly,non-stationary characteristics of the spatial scale,and the effects of influencing factors on grass yield were analyzed using a mixed geographically weighted regression(MGWR)model.The results showed that the model was suitable for correlation analysis.The spatial scale of ratio resident-area index(PRI)was the largest,followed by the digital elevation model,NPP,distance from gully,distance from river,average July rainfall,and daily temperature range;whereas the spatial scales of night light,distance from roads,and relative humidity(RH)were the most limited.All influencing factors maintained positive and negative effects on grass yield,save for the strictly negative effect of RH.The regression results revealed a multiscale differential spatial response regularity of different influencing factors on grass yield.Regression parameters revealed that the results of Ordinary least squares(OLS)(Adjusted R^(2)=0.642)and geographically weighted regression(GWR)(Adjusted R^(2)=0.797)models were worse than those of MGWR(Adjusted R^(2)=0.889)models.Based on the results of the RMSE and radius index,the simulation effect also was MGWR>GWR>OLS models.Ultimately,the MGWR model held the strongest prediction performance(R^(2)=0.8306).Spatially,the grass yield was high in the south and west,and low in the north and east of the study area.The results of this study provide a new technical support for rapid and accurate estimation of grassland yield to dynamically adjust grazing decision in the semi-arid loess hilly region.展开更多
基金funded by the Key Project of Natural Science Foundation of the Ningxia Hui Autonomous Region(2022AAC02020)the Chinese Academy of Engineering and Local Cooperation(2021NXZD8)the Yinchuan Natural Resources Bureau Research Project(022204129004).
文摘Alluvial fans possess diverse geomorphological features and have a significant impact on soil characteristics and variations in ecological stoichiometry.However,it remains unclear how alluvial fans in arid mountainous areas influence the changes in ecological chemical stoichiometry and,consequently,indirectly affect ecosystem function.Alluvial fan,with its diverse topographical features,exerts a multifaceted influence on soil formation and characteristics.Limited information exists regarding the ecological stoichiometric characteristics of the alluvial fan in arid mountainous areas.This study investigated the soil physical-chemical characteristics,enzyme activities,soil ecological stoichiometries,and its driving factors of four types of micro-topographies(alluvial mesas,high floodplain,groove beach,and striated groove)in the foothills of eastern Helan Mountains,China.Results showed that soil physical and chemical properties in the 0–20 cm soil depth was consistently higher than those in the 20–40 cm soil depth,with no changes in pH,total nitrogen,and total potassium.C:P and N:P ratios in alluvial mesas,high floodplain,and striated groove were significantly higher than those in groove beach.Redundancy analysis showed that soil nutrients played the most significant role in the variation of soil ecological stoichiometry characteristics.Topography influenced soil stoichiometry indirectly,primarily through impacts on enzyme activity and soil nutrient elements.These findings elucidate the intricate interplay between soil ecological stoichiometric characteristics and environmental factors across diverse micro-topographies in alluvial fan,contributing to our understanding of the formation and development of soil in dryland.
基金the Key Project of the Natural Science Foundation of Ningxia Hui Autonomous Region,China(2022AAC02020)the Major Strategic Research Project of the Chinese Academy of Engineering and Local Cooperation(2021NXZD8)the Key Research and Development Plan Project of Ningxia Hui Autonomous Region,China(2022004129003).We are grateful to the editors and anonymous reviewers for their insightful comments and suggestions in improving this manuscript.
文摘It is of great significance to study the effects of desert plants on soil enzyme activities and soil organic carbon(SOC)for maintaining the stability of the desert ecosystem.In this study,we studied the responses of soil enzyme activities and SOC fractions(particulate organic carbon(POC)and mineral-associated organic carbon(MAOC))to five typical desert plant communities(Convolvulus tragacanthoides,Ephedra rhytidosperma,Stipa breviflora,Stipa tianschanica var.gobica,and Salsola laricifolia communities)in the proluvial fan in the eastern foothills of the Helan Mountain in Ningxia Hui Autonomous Region,China.We recorded the plant community information mainly including the plant coverage and herb and shrub species,and obtained the aboveground biomass and plant species diversity through sample surveys in late July 2023.Soil samples were also collected at depths of 0–10 cm(topsoil)and 10–20 cm(subsoil)to determine the soil physicochemical properties and enzyme activities.The results showed that the plant coverage and aboveground biomass of S.laricifolia community were significantly higher than those of C.tragacanthoides,S.breviflora,and S.tianschanica var.gobica communities(P<0.05).Soil enzyme activities varied among different plant communities.In the topsoil,the enzyme activities of alkaline phosphatase(ALP)andβ-1,4-glucosidas(βG)were significantly higher in E.rhytidosperma and S.tianschanica var.gobica communities than in other plant communities(P<0.05).The topsoil had higher POC and MAOC contents than the subsoil.Specifically,the content of POC in the topsoil was 18.17%–42.73%higher than that in the subsoil.The structural equation model(SEM)indicated that plant species diversity,soil pH,and soil water content(SWC)were the main factors influencing POC and MAOC.The soil pH inhibited the formation of POC and promoted the formation of MAOC.Conversely,SWC stimulated POC production and hindered MAOC formation.Our study aimed to gain insight into the effects of desert plant communities on soil enzyme activities and SOC fractions,as well as the drivers of SOC fractions in the proluvial fan in the eastern foothills of the Helan Mountain and other desert ecosystems.
文摘为了研究旅游经济发展与生态环境系统之间的空间错位程度,定量分析其空间错位关系,以宁夏为研究对象,基于空间错位理论与模型,综合利用熵权法、TOPSIS(Technique for order prefer⁃ence by similarity to ideal solution)模型、重力模型以及ArcGIS空间可视化表达方法对研究区2011-2018年旅游经济与生态环境系统空间错位程度进行综合分析。结果表明:2011-2018年宁夏旅游经济发展水平与生态环境发展水平分别由0.2868和0.2395增加至0.4716和0.3525,旅游经济实力不断提升,生态环境质量不断改善;从重心转移来看,旅游经济系统重心转移差异不大,而生态环境由南向北发生转移趋势,且两者之间存在比较明显的空间异质性特征;从空间错位程度来看,研究区各地市空间错位程度均较高,且呈现逐年增加的态势。整体来看,宁夏旅游经济与生态环境系统空间错位主要是因旅游区位和旅游资源差异造成的,各地市应结合自身特点,发挥资源优势,挖掘潜力,通过采取差异化的空间矫正策略达到区域旅游产业协调可持续发展的目标。
文摘Ningxia lies in the midland of China, along the upper and middle of the Yellow River.The south of the region belongs to the Loess Plateau and the north of it is Part of theMongolian plateau. The main feature of the climate in the whole region is dry or half dry.The ecological enviroment is in a very delicate state and human activities have made itworse. The severe consequences are widely-spread various types of ecological disasters.
基金Supported by Major Innovation Projects for Building First-class Universities in China’s Western Region(ZKZD2017004)Ningxia Natural Science Foundation(2019AAC03051)
文摘While Yinchuan is not a typical city in China,the process by which its environment,culture and policies have affected its development is typical.The process of urban expansion in Yinchuan reflects the urban development of China in general (or a mirror can reflect China’s development history and policies evolution).Industrial development,local policy orientation,the natural environment,and other factors have both accelerated and restrained the direction and rate of expansion experienced by Yinchuan.The future urban development of Yinchuan can be conducted from three perspectives,including its city planning,and from regional and international perspectives.These perspectives should be applied to encourage city betterment and ecological restoration,new-type urbanization and rural revitalization,regional coordination and cooperation,healthy,livable,intelligent development,and a culturally inclusive atmosphere.
文摘Spatial models are effective in obtaining local details on grassland biomass,and their accuracy has important practical significance for the stable management of grasses and livestock.To this end,the present study utilized measured quadrat data of grass yield across different regions in the main growing season of temperate grasslands in Ningxia of China(August 2020),combined with hydrometeorology,elevation,net primary productivity(NPP),and other auxiliary data over the same period.Accordingly,non-stationary characteristics of the spatial scale,and the effects of influencing factors on grass yield were analyzed using a mixed geographically weighted regression(MGWR)model.The results showed that the model was suitable for correlation analysis.The spatial scale of ratio resident-area index(PRI)was the largest,followed by the digital elevation model,NPP,distance from gully,distance from river,average July rainfall,and daily temperature range;whereas the spatial scales of night light,distance from roads,and relative humidity(RH)were the most limited.All influencing factors maintained positive and negative effects on grass yield,save for the strictly negative effect of RH.The regression results revealed a multiscale differential spatial response regularity of different influencing factors on grass yield.Regression parameters revealed that the results of Ordinary least squares(OLS)(Adjusted R^(2)=0.642)and geographically weighted regression(GWR)(Adjusted R^(2)=0.797)models were worse than those of MGWR(Adjusted R^(2)=0.889)models.Based on the results of the RMSE and radius index,the simulation effect also was MGWR>GWR>OLS models.Ultimately,the MGWR model held the strongest prediction performance(R^(2)=0.8306).Spatially,the grass yield was high in the south and west,and low in the north and east of the study area.The results of this study provide a new technical support for rapid and accurate estimation of grassland yield to dynamically adjust grazing decision in the semi-arid loess hilly region.
