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Parkland trees on smallholder farms ameliorate soil physical-chemical properties in the semi-arid area of Tigray,Ethiopia

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Journal of Arid Land 2024年第1期16卷 1-13页

作者： Selam LJALEM Emiru BIRHANE Kassa TEKA Daniel H BERHE Department of Land resources management and environmental Protection College of Dryland Agriculture and Natural ResourcesMekelle UniversityMekelle 231Ethiopia Institute of Climate and Society Mekelle UniversityMekelle 231Ethiopia Faculty of environmental Sciences and Natural resource management Norwegian University of Life Sciences(NMBU)Ås 1432Norway Department of Natural resources management Adigrat UniversityAdigrat 50Ethiopia

Proposed agroforestry options should begin with the species that farmers are most familiar with,which would be the native multipurpose trees that have evolved under smallholder farms and socioeconomic *** African birch(Anogeissus leiocarpa(DC.)Guill.&Perr.)and pink jacaranda(Stereospermum kunthianum Cham.)trees are the dominant species in the agroforestry parkland system in the drylands of Tigray,*** farmers highly value these trees for their multifunctional uses including timber,firewood,charcoal,medicine,*** trees also could improve soil ***,the amount of soil physical and chemical properties enhanced by the two species must be determined to maintain the sustainable conservation of the species in the parklands and to scale up to similar agroecological ***,we selected twelve isolated trees,six from each species that had similar dendrometric characteristics and were growing in similar environmental *** divided the canopy cover of each tree into three radial distances:mid-canopy,canopy edge,and canopy gap(control).At each distance,we took soil samples from three different *** collected 216 soil samples(half disturbed and the other half undisturbed)from each canopy position and soil *** density(BD),soil moisture content(SMC),soil organic carbon(SOC),total nitrogen(TN),available phosphorus(AP),available potassium(AK),p H,electrical conductivity(EC),and cation exchange capacity(CEC)were *** revealed that soil physical and chemical properties significantly improved except for soil texture and EC under both species,CEC under ***,and soil p H under ***,all the studied soils were improved under both species canopy as compared with canopy ***,TN,AP,and AK under canopy of these trees were respectively 24.1%,11.1%,55.0%,and 9.3% higher than those soils under *** two parkland agroforestry species significantly enhanced soil fertility near the canopy of top

关键词： agroforestry bulk density carbon stock dispersed tree soil texture tree canopy

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Application of plant DNA metabarcoding of lake sediments for monitoring vegetation compositions on the Tibetan Plateau

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Science China Earth Sciences 2024年第11期67卷 3594-3609页

作者： Kai WU Kai LI Weihan JIA Kathleen R.STOOF-LEICHSENRING Ulrike HERZSCHUH Jian NI Mengna LIAO Fang TIAN College of Life Sciences Zhejiang Normal University Polar Terrestrial environmental Systems Research Group Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research Institute of environmental Science and Geography University of Potsdam Institute of Biochemistry and Biology University of Potsdam College of resource Environment and Tourism Capital Normal University

Benefiting from the rapid development of environmental DNA(eDNA) technologies, sedimentary DNA(sedDNA)emerges as a promising tool for monitoring plant compositions in remote regions. The Tibetan Plateau(TP), renowned for its harsh environment and numerous ponds and lakes, presents a potentially demanding region for the application of sedDNA on vegetation investigations. Here, we used the g and h universal primers for the P6 loop region of the chloroplast trn L(UAA)intron to amplify plant DNA in surface sediments from 59 ponds and small lakes on the southwestern TP. The applicability and limitations of using plant DNA metabarcoding for modern vegetation monitoring and palaeo-vegetation reconstructions have been assessed by comparing sedDNA, pollen, and vegetation survey data. Our results showed that plant DNA metabarcoding recorded 186 terrestrial taxa, of which 30.1% can be identified at the species level. The plant sedDNA approach can effectively disclose the dominant plant taxa(including Asteraceae, Cyperaceae and Poaceae) and significant vegetation assemblages in the vicinity of the investigated sites. The number of taxa and taxonomic resolution of plant sedDNA exceeded that of pollen analysis(75 taxa detected, 5.3% can be identified at species level). Unlike pollen that retains a broad spectrum of regional plant signals(including Pinus and Artemisia), plant sedDNA mirrors very local plants, underscoring its utility in local vegetation monitoring and reconstructions. To conclude, plant DNA metabarcoding of(small) lake sediments warrant increased attention in the future for local vegetation monitoring and reconstructions on the TP.

关键词： Sedimentary DNA (sedDNA) Metabarcoding Pollen Vegetation composition Tibetan Plateau

Effects of acid deposition control in China:a review based on responses of subtropical forests

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Frontiers of environmental Science & Engineering 2024年第6期18卷 115-126页

作者： Danni Xie Xiaodong Ge Lei Duan Jan Mulder School of Land Engineering Chang’an UniversityXi’an 710064China State Key Laboratory of environmental Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing 100084China State environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex Beijing 100084China Faculty of environmental Sciences and Natural resource management Norwegian University of Life SciencesBox 5003NO-1432ÅsNorway

For many decades,acid deposition used to pose a significant regional air pollution challenge in *** substantial emission control of anthropogenically derived sulfur and nitrogen containing gasses,both sulfur and nitrogen deposition,as well as the acid rain-affected area,have significantly decreased compared to their peak ***,particularly in the humid subtropics,are sensitive to acid deposition,as evidenced by soil acidification,sulfate and nitrate leaching in stream water,and elevated soil nitrous oxide *** in the total deposition of sulfur and nitrogen,caused a significant decline in sulfate and nitrate leaching from subtropical forest and subsequently in sulfate and nitrate concentrations in stream water,although there was about a 5-year *** delay may be attributed to the desorption of accumulated sulfate and continued elevated mineralization of accumulated nitrogen *** of nitrous oxide,a potent greenhouse gas,also declined in nitrogen-saturated subtropical forest soils,as soil water nitrate concentration ***,subtropical forests in China suffering from elevated acid deposition have begun to ***,the current levels of sulfur and nitrogen deposition continue to exceed the critical loads,i.e.,the assigned threshold levels in accordance with emission control policies,in more than 10%of the country’s land area,respectively,indicating remaining risks of acidification and ***,further emission reductions are urgently needed,also because they will help achieving goals related to air quality and nitrous oxide emissions.

关键词： Acidification Critical load Nitrous oxide Surface water chemistry Recovery

A probe into the acid deposition mitigation path in China over the last four decades and beyond

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National Science Review 2024年第4期11卷 84-92页

作者： Qian Yu Xiaodong Ge Haotian Zheng Jia Xing Lei Duan Dongwei Lv Dian Ding Zhaoxin Dong Yisheng Sun Posch Maximilian Danni Xie Yu Zhao Bin Zhao Shuxiao Wang Jan Mulder Thorj?rn Larssen Jiming Hao State Key Laboratory of environmental Simulation and Pollution Control School of EnvironmentTsinghua University State Key Laboratory of Pollution Control &resource Reuse and School of the Environment Nanjing University State environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex School of EnvironmentTsinghua University International Institute for Applied System Analysis(IIASA) School of Land Engineering Chang'an University Faculty of environmental Sciences and Natural resource management Norwegian University of Life Sciences Norwegian Institute for Water Research

China currently has the highest acid deposition globally, yet research on its status, impacts, causes and controls is lacking. Here, we compiled data and calculated critical loads regarding acid deposition. The results showed that the abatement measures in China have achieved a sharp decline in the emissions of acidifying pollutants and a continuous recovery of precipitation p H, despite the drastic growth in the economy and energy consumption. However, the risk of ecological acidification and eutrophication showed no significant decrease. With similar emission reductions, the decline in areas at risk of acidification in China(7.0%) lags behind those in Europe(20%) or the USA(15%). This was because, unlike Europe and the USA, China's abatement strategies primarily target air quality improvement rather than mitigating ecological impacts. Given that the area with the risk of eutrophication induced by nitrogen deposition remained at 13%of the country even under the scenario of achieving the dual targets of air quality and carbon dioxide mitigation in 2035, we explored an enhanced ammonia abatement pathway. With a further 27% reduction in ammonia by 2035, China could largely eliminate the impacts of acid deposition. This research serves as a valuable reference for China's future acid deposition control and for other nations facing similar challenges.

关键词： acid deposition critical loads acidification eutrophication ammonia abatement

Effect of relative humidity on the desulfurization performance of calcium-based desulfurizer

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Journal of environmental Sciences 2024年第4期138卷 179-188页

作者： Juan Lǖ Yu Fu Haiyan Yu HuanWang Zhe Wang Haiyan Chen School of Environment and resource Southwest University of Science and TechnologyMianyang 621010China Guangyuan Emergency management bureau Guangyuan 628000China

Low desulfurization efficiency impedes the wide application of dry desulfurization technology,which is a low-cost and simple process,and one significant solution is the development and manufacture of high-performance *** this study,firstly,a steam jet mill was used to digest quicklime;then,we utilized numerical simulation to study the flow field distribution and analyze the driving factors of quicklime digestion;and lastly,the desulfurization performance of the desulfurizer was evaluated under different relative *** results show that the desulfurizer prepared via the steam jet mill had better apparent activity than traditional ***,the entire jet flow field of the steam jet mill is in a supersonic and highly turbulent flow state,with high crushing intensity and good particle acceleration *** contact with the nascent surface maximizes the formation of slaked *** experiments demonstrated that the operating time with 100%desulfurization efficiency and the“break-through”time for the desulfurizer prepared via the steam jet mill is longer than that of traditional desulfurizers,and has significant advantages,especially at low flue gas relative *** with traditional desulfurizers,the desulfurizer prepared via steam jet mill expands the range of acceptable flue gas temperature,and the failure temperature is 1.625 times that of traditional *** work breaks through the technical bottleneck of low dry desulfurization efficiency,which is an important step in pushing forward the application of dry desulfurization.

关键词： Dry desulfurization Relative humidity Desulfurization efficiency High-efficiency desulfurizer Quicklime digestion

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Identification of rural courtyards’utilization status using deep learning and machine learning methods on unmanned aerial vehicle images in north China

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Building Simulation 2024年第5期17卷 799-818页

作者： Maojun Wang Wenyu Xu Guangzhong Cao Tao Liu College of resource Environment and Tourism Capital Normal UniversityBeijing 100048China College of Urban and environmental Sciences Peking UniversityBeijing 100871China

The issue of unoccupied or abandoned homesteads(courtyards)in China emerges given the increasing aging population,rapid urbanization and massive rural-urban *** the aspect of rural vitalization,land-use planning,and policy making,determining the number of unoccupied courtyards is *** and questionnaire-based surveys were currently the main approaches,but these traditional methods were often expensive and laborious.A new workflow is explored using deep learning and machine learning algorithms on unmanned aerial vehicle(UAV)***,features of the built environment were extracted using deep learning to evaluate the courtyard management,including extracting complete or collapsed farmhouses by Alexnet,detecting solar water heaters by YOLOv5s,calculating green looking ratio(GLR)by *** precisions exceeded 98%.Then,seven machine learning algorithms(Adaboost,binomial logistic regression,neural network,random forest,support vector machine,decision trees,and XGBoost algorithms)were applied to identify the rural courtyards’utilization *** Adaboost algorithm showed the best performance with the comprehensive consideration of most metrics(Accuracy:0.933,Precision:0.932,Recall:0.984,F1-score:0.957).Results showed that identifying the courtyards’utilization statuses based on the courtyard built environment is *** is transferable and cost-effective for large-scale village surveys,and may contribute to the intensive and sustainable approach to rural land use.

关键词： unoccupied homesteads courtyard built environment inner courtyard management GLR solar water heaters machine learning algorithms

Characteristics of rural domestic sewage discharge and their driving mechanisms: evidence from the Northern Region, China

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Frontiers of environmental Science & Engineering 2024年第7期18卷 47-58页

作者： Jianguo Liu Ziyu Zhou Pengyu Li Zixuan Wang Ying Yan Xuezheng Yu Wenkai Li Tianlong Zheng Yingnan Cao Wenjun Wu Wenqian Cai Zhining Shi Junxin Liu Key Laboratory of environmental Pollution Control and Remediation at Universities of Inner Mongolia Autonomous Region College of Resources and Environmental EngineeringInner Mongolia University of TechnologyHohhot 010051China State Key Laboratory of environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China SCEGC No.12 Construction Engineering Group Co. Ltd.Ankang 725000China State environmental Protection Key Laboratory of environmental Planning and Policy Simulation Chinese Academy of Environmental PlanningBeijing 100041China Technical centre for Soil Agriculture and Rural Ecology and EnvironmentMinistry of Ecology and EnvironmentBeijing 100012China Sustainable Infrastructure and resource management(SIRM) UniSA STEMUniversity of South AustraliaSouth AustraliaMawson LakesSA 5095Australia

The traits of rural domestic sewage emission are unclear,negatively affecting rural domestic sewage treatment and sewage *** study used data from the Second National Pollution Source Census Bulletin to establish a data *** spatial distribution characteristics and main factors influencing rural sewage discharge in the Northern Region were studied using spatial autocorrelation analysis and structural *** findings demonstrated that(l)a significant Spearman correlation between drainage water volume(DwV),chemical oxygen demand(COD),ammonia nitrogen(NH_(3)-N),total nitrogen(TN),and total phosphorus(TP)and that the correlation coefficients between DWV and COD,NH,-N,TNand TP were 0.87**,1.0**,0.99**,0.99**,respectively;(2)rural sewage discharge showed spatial autocorrelation,and rural domestic sewage discharge in the districts and counties with an administration was significantly higher than in the surrounding areas;and(3)social development was the main driver rural domestic sewage changes(path coefficient was 0.407**),and the main factors influencing rural domestic sewage discharge were the urbanization rate,years of education,and population age *** study obtained the spatial variation law and clarified the main influencing factors of rural domestic sewage to provide data support and a theoretical basis for subsequent rural sewage collection and *** of the Inner Mongolia Autonomous Region in northern China as a typical case,provides a theoretical foundation for scientific decision-making on rural domestic sewage treatment at the national and regional levels and offers new perspectives for managing pollutants.

关键词： Rural domestic sewage Emission characteristics Spatial autocorrelation analysis Influencing factors

Spatial Heterogeneity of Embedded Water Consumption from the Perspective of Virtual Water Surplus and Deficit in the Yellow River Basin,China

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Chinese Geographical Science 2024年第2期34卷 311-326页

作者： MA Weijing LI Xiangjie KOU Jingwen LI Chengyi College of Earth and environmental Sciences Lanzhou UniversityLanzhou 730000China State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu 610065China School of Economics and management Ningxia UniversityYinchuan 750021China

Virtual water trade(VWT)provides a new perspective for alleviating water crisis and has thus attracted widespread ***,the heterogeneity of virtual water trade inside and outside the river basin and its influencing factors remains further *** this study,for better investigating the pattern and heterogeneity of virtual water trade inside and outside provincial regions along the Yellow River Basin in 2015 using the input-output model(MRIO),we proposed two new concepts,i.e.,virtual water surplus and virtual water deficit,and then used the Logarithmic Mean Divisia Index(LMDI)model to identify the inherent mechanism of the imbalance of virtual water trade between provincial regions along the Yellow River Basin and the other four regions in *** results show that:1)in provincial regions along the Yellow River Basin,the less developed the economy was,the larger the contribution of the agricultural sector in virtual water trade,while the smaller the contribution of the industrial sector.2)Due to the large output of agricultural products,the upstream and midstream provincial regions of the Yellow River Basin had a virtual water surplus,with a net outflow of virtual water of 2.7×10^(8) m^(3) and 0.9×10^(8) m^(3),respectively.3)provincial regions along the Yellow River Basin were in a virtual water deficit with the rest of China,and the decisive factor was the active degree of trade with the *** study would be beneficial to illuminate the trade-related water use issues in provincial regions along the Yellow River Basin,which has farreaching practical signific-ance for alleviating water scarcity.

关键词： virtual water trade(VWT) input-output model(MRIO) virtual water surplus virtual water deficit Yellow River Basin,China

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Exploring the complex trade-offs and synergies of global ecosystem services

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environmental Science and Ecotechnology 2024年第5期21卷 141-148页

作者： Jinnan Wang Wenjun Wu Meng Yang Yueming Gao Jiacheng Shao Weishan Yang Guoxia Ma Fang Yu Nan Yao Hongqiang Jiang State environmental Protection Key Laboratory of environmental Planning and Policy Simulation Chinese Academy of Environmental PlanningBeijing100041China The Center for Eco-environmental Accounting Chinese Academy of Environmental PlanningBeijing100041China The Innovation Center for Eco-environment-Oriented Development Chinese Academy of Environmental PlanningBeijing100041China School of Environment Beijing Normal UniversityBeijing100875China College of environmental&resource Sciences Zhejiang UniversityHangzhou310058China College of Economics&management Northwest A&F UniversityYangling712100China

The trade-off and synergy relationship of ecosystem services is an important topic in the current *** value of each service provided by the ecosystem is substantially affected by human activities,and conversely,its changes will also affect the relevant human *** to varying tradeoffs among ecosystem services and synergies between them that can either increase or decrease,it is difficult to optimize multiple ecosystem services simultaneously,making it a huge challenge for ecosystem *** study firstly develops a global Gross Ecosystem Product(GEP)accounting *** uses remote sensing data with a spatial resolution of 1 km to estimate the ecosystem services of forests,wetlands,grasslands,deserts,and farmlands in 179 major countries in *** results show that the range of global GEP values is USD 112e197 trillion,with an average value of USD 155 trillion(the constant price),and the ratio of GEP to gross domestic product(GDP)is *** tradeoffs and the synergies among different ecosystem services in each continent and income group have been further *** found a correspondence between the income levels and the synergy among ecosystem services within each *** specific ecosystem services,there are strong synergies between oxygen release,climate regulation,and carbon sequestration services.A trade-off relationship has been observed between flood regulation and other services,such as water conservation and soil retention services in low-income *** results will help clarify the roles and the feedback mechanisms between different stakeholders and provide a scientific basis for optimizing ecosystem management and implementing ecological compensation schemes to enhance human well-being.

关键词： Ecosystem services Biophysical quantity Monetary value Trade-off Synergy