Several ecological restoration projects have been carried out to prevent and restore alpine sandy land,mainly by reestablishing vegetation through planting woody plants and grasses.However,our understanding of how shr...Several ecological restoration projects have been carried out to prevent and restore alpine sandy land,mainly by reestablishing vegetation through planting woody plants and grasses.However,our understanding of how shrub and grass restoration measures affect soil multifunctionality(SMF)in alpine and semi-humid areas remains limited.This study examined the effects of three typical restoration methods—artificial grass plus shrub planting(AGS),artificial grass planting(AG),and artificial shrub planting(AS)-on plant-soil functions and soil multifunctionality,as well as the factors influencing SMF compared to natural grassland(NG).The results showed that vegetation restoration improved aboveground plant characteristics and soil nutrients.Species richness(R),herbaceous plant coverage(Cover),and aboveground biomass(AGB)were higher in AGS than in AS.Soil organic carbon,nitrogen,and phosphorus levels decreased across AGS,AG,and AS,respectively.Additionally,vegetation restoration on sandy land significantly increased soil multifunctionality,with the SMF of AGS reaching 83.92%of that in NG.The structural equation model indicated that plant communities with higher species richness could enhance soil multifunctionality by increasing plant productivity.Compared to NG,soil bulk density negatively affected SMF directly,while soil water content(SWC)directly influenced R and AGB,and indirectly improved SMF through artificial shrub and grass vegetation restoration.Therefore,AGS enhanced SMF more than both AG and AS,and may be a more effective strategy for restoring soil functions in alpine and semi-humid sandy lands.Our findings suggest that combining grasses and shrubs in vegetation restoration offers a more sustainable approach,helping to combat desertification and improve management strategies in the alpine sub-humid region.展开更多
The Hengduan Mountains,situated on the southeastern edge of the Qinghai-Tibet Plateau,are the longest and widest north-south-oriented mountain range in China,exerting a significant influence on the ecological and geog...The Hengduan Mountains,situated on the southeastern edge of the Qinghai-Tibet Plateau,are the longest and widest north-south-oriented mountain range in China,exerting a significant influence on the ecological and geographical pattern.Understanding the topographic and geomorphological characteristics of the Hengduan Mountains is fundamental and crucial for research in related fields such as ecology,geography,and sustainability.In this study,Digital Elevation Model(DEM)data were utilized to extract and analyze the topography and geomorphology(TG)pattern.TG maps have been developed to quantitatively classify the TG types in the Hengduan Mountains by combining the five factors of elevation,slope,aspect,relief and landform.The spatial distribution and quantitative characteristics of these factors were mapped and investigated using geographic information systems.The results revealed that:(1)The Hengduan Mountains exhibit an elongated north-south distribution,with an average elevation of approximately 3746 m,an average slope of around 25°,and an average relief of about 266 m.(2)The Hengduan Mountains display significant elevation differences,with an overall high elevation,characterized by a trend of lower elevation in the east and higher elevation in the west,as well as irregular orientations of various aspects.(3)The 19 landform types were identified,the landform types of the Hengduan Mountains are primarily composed of low-relief high-mountains(42.0618%),low-relief mid-mountains(22.4624%),and high-elevation hills(20.5839%).The results of the study can provide data and information support for the ecology,environmental protection and sustainable development of the Hengduan Mountains.展开更多
The formation potential of four trihalomethanes （THMFP） and seven haloacetic acids （HAA7FP） in 13 source waters taken from four major water basin areas in China was evaluated using the simulated distribution syst...The formation potential of four trihalomethanes （THMFP） and seven haloacetic acids （HAA7FP） in 13 source waters taken from four major water basin areas in China was evaluated using the simulated distribution system （SDS） chlorination method. The specific ultraviolet absorbance （SUVA254： the ratio of UV254 to dissolved organic carbon （DOC））, which ranged between 0.9 and 5.0 L/（mg.m）, showed that the organic compounds in different source waters exhibited different reactivities with chlorine. The HAA7FP of source waters ranged from 20 to 448 μg/L and the THMFP ranged from 29 to 259 μg/L. The HAA7FP concentrations were higher than the THMFP concentrations in all but one of the samples. Therefore, the risks of haloacetic acids （HAAs） should be of concern in some source waters. TCM （chloroform） and BDCM （bromodichloromethane） were the major THM constituents, while TCAA （trichloroacetic acid） and DCAA （dichloroacetic acid） were the major HAA species. Br-THM （brominated THM species） were much higher than Br- HAA （brominated HAA species）, and the formation of Br-DBP （Br-THM and Br-HAA） should be of concern when the bromide concentration is over 100 μg/L.展开更多
The continuous variations of dissolved oxygen （DO）, manganese （Mn）, pH, and their effect on manganese removal by different water treatment processes are investigated. The results show that the declined DO concentr...The continuous variations of dissolved oxygen （DO）, manganese （Mn）, pH, and their effect on manganese removal by different water treatment processes are investigated. The results show that the declined DO concentration and pH value in the bottom of reservoir results in the increasing release of Mn from sediment to source water. Manganese concentration increased from 0.1 to 0.4 mg. L i under the condition that DO concentration decreased from 12.0 to 2.0mg.LI in raw water. The different water treatment processes exhibited different efficiency on manganese removal. The processes with recycling of the suspended sludge, low elevation velocity in settling tank and slow filter rate, will benefit the manganese removal. During a high release of manganese in raw water, traditional coagulation-sedimentation and filtration could not completely remove Mn, although granular activated carbon filtration （GAC） had been applied. At that case, preoxidation with chlorine or potassium permanganate （KMnO4） was necessary to address the high manganese concentration.展开更多
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program of China(No.2019QZKK0307)the National Natural Science Foundation of China(No.42007057)+2 种基金the Sichuan Science and Technology Program(No.2024NSFSC0106)Key R&D project of Ministry of Science and Technology of China(No.2022YFD1601601)the Southwest Minzu University Double World-Class Project(No.CX2023012).
文摘Several ecological restoration projects have been carried out to prevent and restore alpine sandy land,mainly by reestablishing vegetation through planting woody plants and grasses.However,our understanding of how shrub and grass restoration measures affect soil multifunctionality(SMF)in alpine and semi-humid areas remains limited.This study examined the effects of three typical restoration methods—artificial grass plus shrub planting(AGS),artificial grass planting(AG),and artificial shrub planting(AS)-on plant-soil functions and soil multifunctionality,as well as the factors influencing SMF compared to natural grassland(NG).The results showed that vegetation restoration improved aboveground plant characteristics and soil nutrients.Species richness(R),herbaceous plant coverage(Cover),and aboveground biomass(AGB)were higher in AGS than in AS.Soil organic carbon,nitrogen,and phosphorus levels decreased across AGS,AG,and AS,respectively.Additionally,vegetation restoration on sandy land significantly increased soil multifunctionality,with the SMF of AGS reaching 83.92%of that in NG.The structural equation model indicated that plant communities with higher species richness could enhance soil multifunctionality by increasing plant productivity.Compared to NG,soil bulk density negatively affected SMF directly,while soil water content(SWC)directly influenced R and AGB,and indirectly improved SMF through artificial shrub and grass vegetation restoration.Therefore,AGS enhanced SMF more than both AG and AS,and may be a more effective strategy for restoring soil functions in alpine and semi-humid sandy lands.Our findings suggest that combining grasses and shrubs in vegetation restoration offers a more sustainable approach,helping to combat desertification and improve management strategies in the alpine sub-humid region.
基金funded by the Yunnan Provincial Basic Research Joint Special Fund Project(2019FH001(-052))Cangshan Mountain Synthetic Scientific Expeditions Fund.
文摘The Hengduan Mountains,situated on the southeastern edge of the Qinghai-Tibet Plateau,are the longest and widest north-south-oriented mountain range in China,exerting a significant influence on the ecological and geographical pattern.Understanding the topographic and geomorphological characteristics of the Hengduan Mountains is fundamental and crucial for research in related fields such as ecology,geography,and sustainability.In this study,Digital Elevation Model(DEM)data were utilized to extract and analyze the topography and geomorphology(TG)pattern.TG maps have been developed to quantitatively classify the TG types in the Hengduan Mountains by combining the five factors of elevation,slope,aspect,relief and landform.The spatial distribution and quantitative characteristics of these factors were mapped and investigated using geographic information systems.The results revealed that:(1)The Hengduan Mountains exhibit an elongated north-south distribution,with an average elevation of approximately 3746 m,an average slope of around 25°,and an average relief of about 266 m.(2)The Hengduan Mountains display significant elevation differences,with an overall high elevation,characterized by a trend of lower elevation in the east and higher elevation in the west,as well as irregular orientations of various aspects.(3)The 19 landform types were identified,the landform types of the Hengduan Mountains are primarily composed of low-relief high-mountains(42.0618%),low-relief mid-mountains(22.4624%),and high-elevation hills(20.5839%).The results of the study can provide data and information support for the ecology,environmental protection and sustainable development of the Hengduan Mountains.
基金supported by the High-Tech Research and Development Program (863) of China(No.2007AA06A414)the National Basic Research Development Program (973) of China(No. 2006CB403306)the Chinese Academy of Sciences Major Projects of Knowledge Innovation Program(No. KZCX1-YW-06)
文摘The formation potential of four trihalomethanes （THMFP） and seven haloacetic acids （HAA7FP） in 13 source waters taken from four major water basin areas in China was evaluated using the simulated distribution system （SDS） chlorination method. The specific ultraviolet absorbance （SUVA254： the ratio of UV254 to dissolved organic carbon （DOC））, which ranged between 0.9 and 5.0 L/（mg.m）, showed that the organic compounds in different source waters exhibited different reactivities with chlorine. The HAA7FP of source waters ranged from 20 to 448 μg/L and the THMFP ranged from 29 to 259 μg/L. The HAA7FP concentrations were higher than the THMFP concentrations in all but one of the samples. Therefore, the risks of haloacetic acids （HAAs） should be of concern in some source waters. TCM （chloroform） and BDCM （bromodichloromethane） were the major THM constituents, while TCAA （trichloroacetic acid） and DCAA （dichloroacetic acid） were the major HAA species. Br-THM （brominated THM species） were much higher than Br- HAA （brominated HAA species）, and the formation of Br-DBP （Br-THM and Br-HAA） should be of concern when the bromide concentration is over 100 μg/L.
文摘The continuous variations of dissolved oxygen （DO）, manganese （Mn）, pH, and their effect on manganese removal by different water treatment processes are investigated. The results show that the declined DO concentration and pH value in the bottom of reservoir results in the increasing release of Mn from sediment to source water. Manganese concentration increased from 0.1 to 0.4 mg. L i under the condition that DO concentration decreased from 12.0 to 2.0mg.LI in raw water. The different water treatment processes exhibited different efficiency on manganese removal. The processes with recycling of the suspended sludge, low elevation velocity in settling tank and slow filter rate, will benefit the manganese removal. During a high release of manganese in raw water, traditional coagulation-sedimentation and filtration could not completely remove Mn, although granular activated carbon filtration （GAC） had been applied. At that case, preoxidation with chlorine or potassium permanganate （KMnO4） was necessary to address the high manganese concentration.
