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Impact of Sky Conditions on Net Ecosystem Productivity over a “Floating Blanket” wetland in Southwest China

Advances in Atmospheric Sciences 2024年第2期41卷 355-368页

作者： Yamei SHAO Huizhi LIU Qun DU Yang LIU Jihua SUN Yaohui LI Jinlian LI State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100029China Yunnan Meteorological Observatory Kunming 530100China College of Aviation Meteorology Civil Aviation Flight University of ChinaGuanghan 618307China Meteorological Bureau of Tengchong County Baoshan 679100China

Based on eddy covariance(EC) measurements during 2016–20, the effects of sky conditions on the net ecosystem productivity(NEP) over a subtropical “floating blanket ” wetland were investigated. Sky conditions were divided into overcast, cloudy, and sunny conditions. On the half-hourly timescale, the daytime NEP responded more rapidly to the changes in the total photosynthetic active radiation(PARt) under overcast and cloudy skies than that under sunny skies. The increase in the apparent quantum yield under overcast and cloudy conditions was the greatest in spring and the least in summer. Additionally, lower atmospheric vapor pressure deficit(VPD) and moderate air temperature were more conducive to enhancing the apparent quantum yield under cloudy skies. On the daily timescale, NEP and the gross primary production(GPP) were higher under cloudy or sunny conditions than those under overcast conditions across seasons. The daily NEP and GPP during the wet season peaked under cloudy skies. The daily ecosystem light use efficiency(LUE) and water use efficiency(WUE) during the wet season also changed with sky conditions and reached their maximum under overcast and cloudy skies, respectively. The diffuse photosynthetic active radiation(PAR_d) and air temperature were primarily responsible for the variation of daily NEP from half-hourly to monthly timescales, and the direct photosynthetic active radiation(PAR_b) had a secondary effect on NEP. Under sunny conditions, PAR_b and air temperature were the dominant factors controlling daily NEP. While daily NEP was mainly controlled by PAR_d under cloudy and overcast conditions.

关键词： diffuse radiation eddy covariance NEP controlling factors wetland path analysis

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Pattern of spatial variability in granulometric and mineralogical characteristics across an ecologically sensitive sub-tropical wetland(Bihar, India)

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International Journal of Sediment Research 2023年第4期38卷 516-529页

作者： Alvia Aslam Rajesh Kumar Ranjan Avinash Dass Department of Environmental Science Central University of South Bihar

Floodplain wetlands are dynamic systems undergoing frequent hydro-sedimentological changes. Tropical/subtropical wetlands have even more pronounced climatic and biological influences on the sediment dynamics. In the current study, a protected subtropical wetland in Bihar(India) has been assessed for its sedimentary and mineralogical status. Sediment characteristics and associated granulometric parameters are discussed to highlight the wetland’s hydrogeomorphic character, energy dimension, and the depositional processes taking place. Statistical grain size parameters like graphic mean, graphic skewness,graphic kurtosis, and their interrelations studies have helped in understanding the sources of deposited materials. Multivariate statistics have identified, sand fractions, measures of central tendencies(mean,median, and mode), percent organic matter(%OM) and percent carbonates(%carbonates) as primary factors explaining the maximum variance in the data. The non-parametric Kruskal-Wallis test has identified %sand, %clay, electrical conductivity(EC), and %carbonates as the major factors responsible for significant spatial variability. The grain texture analysis shows that the majority of samples fall in the brackets of clayey silt; silty sand; and sand, silt, and clay. Common mineral components associated with these are quartz, feldspar, clay minerals, etc. The range for the mean grain size lies between 3Φ to 9Φ(Φ is diameter of the sediments) where most of the grain size distributions are symmetrically to fine symmetrically skewed, indicating intermediate energy to adjust to environmental conditions. The granulometric and physicochemical characteristics of the sediment samples also indicate the directional distribution pattern of sediment along the hydrological pathway. Future studies concentrating on the fluvial discharges of water and sediment will be highly insightful in reconstructing the past net sediment accumulation processes in the Baraila wetland.

关键词： Grain size analysis Hydrodynamic energy Mineralogy Allogenic source Terrigenous input wetland

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The Synergism between Methanogens and Methanotrophs and the Nature of their Contributions to the Seasonal Variation of Methane Fluxes in a wetland:The Case of Dajiuhu Subalpine Peatland

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Advances in Atmospheric Sciences 2022年第8期39卷 1375-1385,I0017-I0023页

作者： Luwen WANG Jiwen GE Liang FENG Yaoyao LIU Yu LI Jiumei WANG Xiang XIAO Zhiqi ZHANG Laboratory of Basin Hydrology and wetland Eco-Restoration China University of GeosciencesWuhan 430074China Hubei Key Laboratory of wetland Evolution and Ecological Restoration China University of GeosciencesWuhan 430074China Institution of Ecology and Environmental Sciences China University of GeosciencesWuhan 430074China Shennongjia National Park Administration Bureau Shennongjia Forestry District 442417China

wetland ecosystems are the most important natural methane(CH_(4))sources,whose fluxes periodically fluctuate.Methanogens(methane producers)and methanotrophs(methane consumers)are considered key factors affecting CH_(4)fluxes in wetlands.However,the symbiotic relationship between methanogens and methanotrophs remains unclear.To help close this research gap,we collected and analyzed samples from four soil depths in the Dajiuhu subalpine peatland in January,April,July,and October 2019 and acquired seasonal methane flux data from an eddy covariance(EC)system,and investigated relationships.A phylogenetic molecular ecological networks(pMENs)analysis was used to identify keystone species and the seasonal variations of the co-occurrence patterns of methanogenic and methanotrophic communities.The results indicate that the seasonal variations of the interactions between methanogenic and methanotrophic communities contributed to CH_(4)emissions in wetlands.The keystone species discerned by the network analysis also showed their importance in mediating CH_(4)fluxes.Methane(CH_(4))emissions in wetlands were lowest in spring;during this period,the most complex interactions between microbes were observed,with intense competition among methanogens while methanotrophs demonstrated better cooperation.Reverse patterns manifested themselves in summer when the highest CH_(4)flux was observed.Methanoregula formicica was negatively correlated with CH_(4)fluxes and occupied the largest ecological niches in the spring network.In contrast,both Methanocella arvoryzae and Methylocystaceae demonstrated positive correlations with CH_(4)fluxes and were better adapted to the microbial community in the summer.In addition,soil temperature and nitrogen were regarded as significant environmental factors to CH_(4)fluxes.This study was successful in explaining the seasonal patterns and microbial driving mechanisms of CH_(4)emissions in wetlands.

关键词： CH_(4)fluxes wetland methanogens methanotrophs molecular ecological network

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wetland loss in Turkey over a hundred years:implications for conservation and management

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Ecosystem Health and Sustainability 2021年第1期7卷 174-186页

作者： Murat Ataol Ortaç Onmuş Department of Geography ÇankırıKaratekin UniversityÇankırıTurkey Natural History Museum Research and Application Centre and Department of BiologyEge UniversityIzmirTurkey

The aims of this study were to provide a complete inventory of wetlands in Turkey including their past status(1910-1930)in comparison to the present time(2014).The types of wetlands and their area sizes were determined by using cartographical maps of 1/200,000 in scale made between 1910s and 1920s vs.2006 CORINE Land Cover data,which were updated with Landsat 8 satellite images in 2014.The effect of possible climate change on wetlands sizes various local,national and regional rainfall datasets were analysed by correlation and regression analysis.A hundred years ago,the total number of natural wetlands was 1299 with a total surface area of 1,376,505 hectares.In 2014,the total number of natural wetlands had decreased to 900,with a total surface area of 1,085,936 hectares,so that 21.2%of the original wetlands were lost(291,339 hectares).The observed changes in the number of wetlands and their relative sizes cannot be attributed directly to changes in climate.wetland drainage was largely responsible for observed wetland losses,but local changes in precipitation regimes partially contributed to this loss.Urgent conservation and restoration of wetlands are recommended to avoid further loss of wetlands in Turkey.

关键词： wetland wetland loss drainage dams and reservoirs turkey conservation and management areal extent

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Performance of different macrophytes in the decontamination of and electricity generation from swine wastewater via an integrated constructed wetland-microbial fuel cell process

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Journal of Environmental Sciences 2020年第3期32卷 252-263页

作者： Feng Liu Lei Sun Jinbao Wan Liang Shen Yanhong Yu Lingling Hu Ying Zhou School of Resources Environmental&Chemical Engineering Nanchang UniversityJiangxi 330031China School of Chemistry and Chemical Engineering Jiangxi Science and Technology Normal UniversityJiangxi 330013China Jiangxi Engineering Laboratory of Waterborne Coating School of Chemistry and Chemical EngineeringJiangxi Science and Technology Normal UniversityJiangxi 330013China School of Materials and Mechanical&Electrical Engineering Jiangxi Science and Technology Normal UniversityJiangxi 330013China

Plants constitute a major element of constructed wetlands(CWs).In this study,a coupled system comprising an integrated vertical flow CW(IVCW) and a microbial fuel cell(MFC) for swine wastewater tre atment was developed to research the effects of macrophytes commonly employed in CWs,Canna indica,Acorus calamus,and Ipomoea aquatica,on decontamination and electricity production in the system.Because of the different root types and amounts of oxygen released by the roots,the rates of chemical oxygen demand(COD) and ammonium nitrogen(NH4^+-N) removal from the swine wastewater differed as well.In the unplanted,Canna indica,Acorus calamus,and Ipomoea aquatica systems,the COD removal rates were 80.20%,88.07%,84.70%,and 82.20%,respectively,and the NH4+-N removal rates were 49.96%,75.02%,70.25%,and 68.47%,respectively.The decontamination capability of the Canna indica system was better than those of the other systems.The average output voltages were 520±42,715±20,660±27,and 752±26 mV for the unplanted,Canna indica,Acorus calamus,and Ipomoea aquatica systems,respectively,and the maximum power densities were 0.2230,0.4136,0.3614,and0.4964 W/m^3,respectively.Ipomoea aquatica had the largest effect on bioelectricity generation promotion.In addition,electrochemically active bacteria,Geobacter and Desulfuromonas,were detected in the anodic biofilm by high-throughput sequencing analysis,and Comamonas(Proteobacteria),which is widely found in MFCs,was also detected in the anodic biofilm.These results confirmed the important role of plants in IVCW-MFCs.

关键词： Integrated vertical flow constructed wetland Microbial fuel cell Swine wastewater Dissolved oxygen(DO)

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Environmental degradation through mining for energy resources:The case of the shrinking Laguna Santa Rosa wetland in the Atacama Region of Chile

Energy Geoscience

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Energy Geoscience 2022年第2期3卷 182-190页

作者： Mohammad Ayaz Alam Rosa Sepúlveda Departamento de Geología Facultad de IngenieríaUniversidad de AtacamaAvenida Copayapu 485CopiapoRegion de AtacamaChile

As the world strives to replace fossil fuels with clean energy e reflected by global surge in the number of electric vehicles e the environmental impact of mining all the lithium(Li)needed to enable such a transformation has become a problem in its own right.In South America,the biggest problem is the excessive use of water in Li extraction process in one of the driest areas in the world.Apart from causing severe friction over water rights between local communities and mining companies,it puts enormous pressure on the region's fragile and poorly understood wetland ecosystems.wetlands are one of the most threatened ecosystems on the Earth,despite their great importance as habitats for a vast number of species and corresponding to one of the most productive environments.Present work is the outcome of an investigation on Laguna Santa Rosa's(LSR)vulnerability resulting from ongoing metal mining operations in its surroundings that require a large volume of water extracted from local aquifers,in addition to a high evaporation rate in the area.This groundwater-dependent wetland will soon be further vulnerable with the commencement of water-intensive Li mining at Salar de Maricunga,with the extraction project already having an environmental impact study approved.Sustainability of this wetland protected under the Ramsar Convention and home to numerous wildlife species habiting this highland sector of the Andean Cordillera is vital for the associated ecosystems.The variation in the water surface area of LSR has been deciphered through the application of a Landsat-5 Thematic Mapper(TM)satellite image collection.This has been done both for the hydrological year 2016e2017 and 1993-2014 period.A decreasing trend in the water surface area of LSR,a hypersaline lake at the southern extreme of Salar de Maricunga,a salt flat in the Atacama Region of Chile,was observed through the study of satellite images between 1993 and 2014,showing shrinking of this wetland.However,this shrinking trend was punctuated by extreme rainfall and cons

关键词： Laguna Santa Rosa Salar de Maricunga Lithium Water wetland Ecosystem

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Dynamic Response of Phragmites australis and Suaeda salsa to Climate Change in the Liaohe Delta wetland

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Journal of Meteorological Research 2021年第1期35卷 157-171页

作者： Yushu ZHANG Wenying YU Ruipeng JI Yijun ZHAO Rui FENG Qingyu JIA Jinwen WU Institute of Atmospheric Environment China Meteorological AdministrationShenyang 110166 Key Laboratory of Agrometeorological Disasters of Liaoning Province Shenyang 110166 Panjin Meteorological Service Center Liaoning Meteorological BureauPanjin 124010

Because of its unique geographical location and ecological function, the Liaohe Delta wetland is important in maintaining regional ecological balance and security. Monitoring and evaluating changes in the wetland are therefore of great importance. We used medium-and high-resolution satellite data, meteorological station data, and site measurement data to analyze changes in the area and spatial distribution of Phragmites australis and Suaeda salsa in the Liaohe Delta wetland from 1998 to 2017, as well as their growth response to the climate change. The results showed that during 1998–2017, the areas of both P. australis and S. salsa wetlands alternated through periods of decreasing,increasing, and then decreasing trends. The annual change in the area and spatial distribution range of S. salsa fluctuated more than that of P. australis. The annual variation of normalized difference vegetation index(NDVI) in P. australis wetland showed an upward trend from 1998 to 2017. The area of P. australis cover that was improved, unchanged, and decreased accounted for 81.8%, 12.3%, and 5.9%, respectively, of the total area;evaporation and wind speed were the main meteorological factors affecting the NDVI;and contribution rates of the climate change and human activities to the NDVI were 73.2% and 26.8%, respectively. The area with vegetation cover being mainly S.salsa that was improved, unchanged, and decreased accounted for 63.3%, 18.3%, and 18.4%, respectively, of the total area;and no meteorological factors significantly affected the NDVI of S. salsa in the region. The interaction between vegetation growth and meteorological factors may help to explain the increasing trend in vegetation cover.The improvement in wetland vegetation also led to carbon sequestration and an increase in sequestration capacity.

关键词： Liaohe Delta wetland Phragmites australis Suaeda salsa climate change

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Nitrate removal to its fate in wetland mesocosm filled with sponge iron:Impact of influent COD/N ratio

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Frontiers of Environmental Science & Engineering 2020年第1期14卷 77-85页

作者： Zhihao Si Xinshan Song Xin Cao Yuhui Wang Yifei Wang Yufeng Zhao Xiaoyan Ge Awet Arefe Tesfahunegn College of Environmental Science and Engineering State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile IndustryDonghua UniversityShanghai 201620China

Sponge iron(s-Fe°)is a porous metal with the potential to be an electron donor for denitrification.This study aims to evaluate the feasibility of using s-Fe as the substrate of wetland mesocosms.Here,wetland mesocosms with the addition of s-Fe"particles(CW-Fc)and a blank control group(CW-CK)were established.The NOj-N reduction property and water quality parameters(pH.DO.and ORP)were examined at three COD/N ratios(0.***.and 10).Results showed that the NO3--N removal efficiencies were significantly increased by 6.6 to 58.9%in the presence of s-Fe NH4+-N was mainly produced by chemical denitrification,and approximately 50% of the NO3--N was reduced to N4+-N,at the COD ratio of 0.An increase of the influent COD/N ratio resulted in lower chemical denitrification and higher bio-dcnitrification.Although chemical denitrification mediated by s-Fe led to an accumulation of NH4+-N at COD/N ratios of 0 and 5.the TIN removal efficiencies increased by 4.5#12.4#.Moreover,the effluent pll,DO.and ORP values showed a significant negative correlation with total Fe and Fe(II)(Pwetland mcsocosm.

关键词： Sponge iron wetland mesocosm Electronic donor Denitrification COD/N ratio

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Prediction of spatial land use changes based on LCM in a GIS environment for Desert wetlands-A case study: Meighan wetland,Iran

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International Soil and Water Conservation Research 2019年第1期7卷 64-70页

作者： Amir Ansari Mohammad H.Golabi Department of Environmental Sciences Faculty of Agriculture and Natural ResourcesArak UniversityArak 38156-8-8349Iran College of Natural and Applied Sciences University of Guam MangilaoGuam 96923United States

Meighan wetland and its surroundings have undergone many changes in recent years.This study aims to monitor and predict land use changes using the land change model (LCM) module in the Meighan wetland.Land Sat images of years 2000,2007 and 2015 were used to produce digital land use maps.The images were classified into seven classes including;Salt lake,Agriculture,Rangeland,Manmade,Wastewater,wetland and Mine areas.The LCM module in Idrisi GIS software was used to analyze the land use changes for predicting the land uses status in 2015,based on artificial neural network (ANN) and Markov Chain analysis.The ANN was trained with various influencing factors including;distance from road,distance from manmade areas,distance from land changed edge,distance from stream,elevation and slope.The results indicated that 1663.88 ha of the rangeland cover and 715.68 ha of the salt lake cover have been degraded during the 2000-2015 period.Furthermore,the wetland,mine,wastewater and manmade degradation are increased to 724 ha,335 ha,37 ha and 270 ha in comparison to initial land conditions.Also,the result shows that rangeland and salt lake areas will decrease in the year 2030 compare to 2015,while,wetland,mine and manmade land changes may increase.

关键词： LCM Prediction Meighan wetland Land use changes Artificial Neural Network

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OBH-RSI:Object-Based Hierarchical Classification Using Remote Sensing Indices for Coastal wetland

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Journal of Beijing Institute of Technology 2021年第2期30卷 159-171页

作者： Zhaoyang Lin Jianbu Wang Wei Li Xiangyang Jiang Wenbo Zhu Yuanqing Ma Andong Wang Beijing Key Laboratory of Fractional Signals and Systems Beijing Institute of TechnologyBeijing 100081China Laboratory of Marine Physics and Remote Sensing First Institute of OceanographyMinistry of Natural ResourcesQingdao 266061China Shandong Provincial Key Laboratory of Restoration for Marine Ecology Shandong Marine Resources and Environment Research InstituteYantai 264006China Shandong Yellow River Delta National Nature Reserve Administration Committee Dongying 257091China

With the deterioration of the environment,it is imperative to protect coastal wetlands.Using multi-source remote sensing data and object-based hierarchical classification to classify coastal wetlands is an effective method.The object-based hierarchical classification using remote sensing indices(OBH-RSI)for coastal wetland is proposed to achieve fine classification of coastal wetland.First,the original categories are divided into four groups according to the category characteristics.Second,the training and test maps of each group are extracted according to the remote sensing indices.Third,four groups are passed through the classifier in order.Finally,the results of the four groups are combined to get the final classification result map.The experimental results demonstrate that the overall accuracy,average accuracy and kappa coefficient of the proposed strategy are over 94%using the Yellow River Delta dataset.

关键词： Yellow River Delta vegetation index object-based hierarchical classification wetland multi-source remote sensing

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