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Agricultural non-point nitrogen pollution control function of dierent vegetation types in riparian wetlands: A case study in the Yellow River wetland in China

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Journal of environmental Sciences 2009年第7期21卷 933-939页

作者： ZHAO Tongqian XU Huashan HE Yuxiao TAI Chao MENG Hongqi ZENG Fanfu XING Menglin Institute of Resources and environment Henan Polytechnic University Jiaozuo 454003 China henan province environmental monitoring center Zhengzhou 450004 China

Riparian wetland is the major transition zone of matter, energy and information transfer between aquatic and terrestrial ecosystems and has important functions of water purification and non-point pollution control. Using the field experiment method and an isotope tracing technique, the agricultural non-point nitrogen pollution control function of different vegetation types in riparian wetland was studied in the Kouma Section of the Yellow River. The results showed that the retention of agricultural non-point nitrogen pollution by riparian wetland soil occurs mainly in top 0-10 cm layer. The amount of nitrogen retained by surface soils associated with three types of vegetation are 0.045 mg/g for Phragmites communis Trin Linn, 0.036 mg/g for Scirpus triqueter Linn, and 0.032 mg/g for Typha angustifolia Linn, which account for 59.21%, 56.25%, and 56.14% of the total nitrogen interception, respectively. Exogenous nitrogen in 0-10 cm soil layer changes more quickly than in other layers. One month after adding KISNO3 to the tested vegetation, nitrogen content was 77.78% for P communis Trin, 68.75% for T. angustifolia, and 8.33% for S. triqueter in the surface soil. After three months, nitrogen content was 93.33% for P. communis Trin, 72.22% for S. triqueter, and 37.50% for T. Angustifolia. There are large differences among vegetation communities respecting to purification of agricultural non-point nitrogen pollution. The nitrogen uptake amount decreases in the sequence： new shoots ofP. communis Trin （9.731 nag/g）〉 old P. communis Trin （4.939 mg/g）〉 S. triqueter （0.620 mg/g）〉 T. angustifolia （0.186 mg/g）. Observations indicated that the presence of riparian wetlands as buffers on and adjacent to stream banks could be recommended to control agricultural non-point pollution.

关键词： riparian wetland vegetation community agricultural non-point source nitrogen pollution

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Characteristics and source apportionment of ambient volatile organic compounds and ozone generation sensitivity in urban Jiaozuo,China

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Journal of environmental Sciences 2024年第4期138卷 607-625页

作者： Pengzhao Li Chun Chen Dan Liu Jie Lian Wei Li Chuanyi Fan Liangyu Yan Yue Gao Miao Wang Hang Liu Xiaole Pan Jing Mao State Centre for International Cooperation on Designer Low-Carbon and environmental Materials School of Materials Science and EngineeringZhengzhou UniversityZhengzhou 450001China henan Key Laboratory of environmental monitoring Technology Henan Ecological Environment Monitoring and Safety CenterZhengzhou 450046China Jiaozuo ecological environment monitoring center of henan province Jiaozuo 454003China State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

In recent years,many cities have taken measures to reduce volatile organic compounds(VOCs),an important precursor of ozone(O_(3)),to alleviate O_(3) pollution in China.116 VOC species were measured by online and offline methods in the urban area of Jiaozuo from May to October in 2021 to analyze the compositional *** sources were analyzed by a positive matrix factorization(PMF)model,and the sensitivity of ozone generation was determined by ozone isopleth plotting research(OZIPR)*** results showed that the average volume concentration of total VOCs was 30.54 ppbv and showed a bimodal feature due to the rush-hour traffic in the morning and at *** most dominant VOC groups were oxygenated VOCs(OVOCs,29.3%)and alkanes(26.7%),and the most abundant VOC species were acetone and ***,based on the maximum incremental reactivity(MIR)method,the major VOC groups in terms of ozone formation potential(OFP)contribution were OVOCs(68.09μg/m^(3),31.5%),aromatics(62.90μg/m^(3),29.1%)and alkene/alkynes(54.90μg/m^(3),25.4%).This indicates that the control of OVOCs,aromatics and alkene/alkynes should take *** sources of VOCs were quantified by PMF,including fixed sources of fossil fuel combustion(27.8%),industrial processes(25.9%),vehicle exhaust(19.7%),natural and secondary formation(13.9%)and solvent usage(12.7%).The empirical kinetic modeling approach(EKMA)curve obtained by OZIPR on O_(3) exceedance days indicated that the O_(3) sensitivity varied in different *** results provide theoretical support for O_(3) pollution prevention and control in Jiaozuo.

关键词： Volatile organic compounds(VOCs) Online and offline measurement Ozone formation potential(OFP) Positive matrix factorization(PMF) Ozone isopleth plotting research(OZIPR) Jiaozuo

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Lake regime shift from submerged macrophyte to phytoplankton affected phosphorus speciation in sediment and eutrophic state in Caohai Lake,Guizhou,China

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Journal of Oceanology and Limnology 2023年第6期41卷 2262-2275页

作者： Jixing DONG Yanmin GUO Pinhua XIA Yuanbin TIAN Feifei ZHENG Anyan LI Tao LIN Ruiwen LI Guizhou province Key Laboratory for Information System of Mountainous Areas and Protection of ecological environment Guizhou Normal UniversityGuiyang 550001China Yangtze River Basin ecological environment monitoring and Scientific Research center Yangtze River Basin Ecological Environment Supervision and Administration BureauMinistry of Ecological EnvironmentWuhan 430010China

To understand the effect of regime shift in Caohai Lake in Yunnan-Guizhou Plateau,SW China from submerged macrophyte dominance to phytoplankton dominance on the specification and distribution of phosphorus and on ecological and environmental states,changes in phosphorus specification in the sediments and water were *** form,composition,and distribution of phosphorus in sediment were sampled in July 2020(before regime shift)and July 2021(after regime shift)were *** reveal that phosphorus content in sediment was lower than that those of Erhai Lake and Dianchi Lake,Yunnan,SW China,on the same plateau,and was lower than those of Taihu Lake,Chaohu Lake,and Poyang Lake in the middle-lower Changjiang(Yangtze)River *** phosphorus(Or-P)was the main form(up to 60%),followed by inactive phosphorus(Ina-P),and the active phosphorus(Act-P),the least,which is opposite to those of Taihu Lake and Poyang Lake in the middle-lower Changjiang River Plain in the eastern ***-P content was high,indicating a high potential risk of phosphorous *** the regime shift,the total phosphorus in sediment decreased from 0.87±0.13 to 0.70±0.13 g/*** proportion of Or-P and Act-P decreased from 68.23% to 65.32% and from 5.35% to 4.69%,*** contrast,the proportion of Ina-P increased from 26.42% to 29.99%.The Moran’s I index revealed that the heterogeneity of the spatial distributions of the total phosphorus(S-TP)and Act-P in the sediments before regime shift was significant(P0.05).The regime shift aggravated the eutrophication of the lake,the trophic level index(TLI)increased from 48.42 to 54.49(P<0.01),and the previously mesotrophic lake became a mildly eutrophic *** results of this study revealed the impact of regime shift in the lake from submerged macrophyte dominance to phytoplankton dominanc

关键词： Caohai Lake sediment phosphorus specification regime shift

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A numerical study of hydrodynamic characteristics and hydrological processes in the coastal wetlands during extreme events

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Journal of Hydrodynamics 2023年第5期35卷 963-979页

作者： Ming-liang Zhang Xiao-sen Zhu Yu-jia Wang Heng-zhi Jiang Lei Cui College of Ocean Science and environment Dalian Ocean UniversityDalian116023China Technology Innovation center for Coastal ecological environment and Disaster Protection Liaoning ProvinceDalian116023China National Marine environmental monitoring center Dalian116023China

Providing accurate predictions of extreme water levels through numerical simulation has become essential for disaster prevention and damage mitigation in coastal wetland *** study applies the FVCOM model to simulate storm surges caused by several typhoons in the Bohai Sea and the North Huanghai *** vegetation drag force caused by salt marsh plants is inserted into the FVCOM model for model improvement with vegetation effect by integrating RS and GIS technologies.A parametric typhoon model is coupled with background wind fields derived to acquire the spatio-temporal variations of wind and pressure fields in the computational *** simulation results reproduce the extreme storm surges induced by typhoon events very *** modeling results are compared by validating with literature results to examine the effect of vegetation on tidal waves in tidal mud ***,the coupled model is also applied to explore storm surge attenuation and land intrusion during Typhoon Winnie in the wetlands of the Liao River *** simulation results indicate that salt marsh plants can reduce the flow current with little impact on tide flooding/ebbing in vegetated ***,the results show that typhoon presence increases the inundation depth and extendes the flood time in the tidal wetlands of the study *** FVCOM model incorporating the method with vegetation drag force can provide new insights to understand the comprehensive impact of tidal wetland plants on hydrodynamic characteristics in the Bohai Sea and other waters,hence presents a more accurate quantification of the hydrological process of storm surge in the tidal wetlands.

关键词： FVCOM circulation model Parametric typhoon model coastal wetlands storm surge hydrological process

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Implications of 1.5 K climate warming on warm-season ozone exposure and atmospheric oxidation capacity in China

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Atmospheric and Oceanic Science Letters 2024年第6期17卷 53-61页

作者： Zhihao Shi Lin Huang Xiaodong Xie Momei Qin Jingyi Li Bingye Xu Lingling Jin Jianlin Hu College of environment Henan Normal UniversityXinxiangChina Jiangsu Key Laboratory of Atmospheric environment monitoring and Pollution Control Collaborative Innovation Center of Atmospheric Environment and Equipment TechnologyNanjing University of Information Science&TechnologyNanjingChina ecological and environmental monitoring center of Zhejiang province HangzhouChina

Surface ozone(O_(3))poses significant threats to public health,agricultural crops,and plants in natural *** warming is likely to increase future O_(3)mainly by altering atmospheric photochemical reactions and enhancing biogenic volatile organic compound(BVOC)*** assess the impacts of the future 1.5 K climate target on O_(3)concentrations and ecological O_(3)exposure in China,numerical simulations were conducted using the CMAQ(Community Multiscale Air Quality)model during April-October *** O_(3)exposure was estimated using six indices(i.e.,M7,M24,N100,SUM60,W126,and AOT40f).The results show that the temperature rise increases the MDA8 O_(3)(maximum daily eight-hour average O_(3))concentrations by∼3 ppb and the number of O_(3)exceedance days by 10-20 days in the North China Plain(NCP),Yangtze River Delta(YRD),and Sichuan Basin(SCB)*** O_(3)exposure indices show substantial increases.M24 and M7 in eastern and southern China will rise by 1-3 ppb and 2-4 ppb,respectively.N100 increases by more than 120 h in the surrounding regions of ***60 increases by greater than 9 ppm h^(−1),W126 increases by greater than 15 ppm h^(−1)in Shaanxi and SCB,and AOT40f increases by 6 ppm h^(−1)in NCP and *** temperature increase also promotes atmospheric oxidation capacity(AOC)levels,with the higher AOC contributed by OH radicals in southern China but by NO_(3)radicals in northern *** change in the reaction rate caused by the temperature increase has a greater influence on O_(3)exposure and AOC than the change in BVOC emissions.

关键词： Temperature increase Ozone exposure Biogenic emissions Atmospheric oxidation capacity

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Phyllosphere eukaryotic microalgal communities in rainforests:Drivers and diversity

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Plant Diversity 2023年第1期45卷 45-53页

作者： Ben-Wen Liu Shu-Yin Li Huan Zhu Guo-Xiang Liu Key Laboratory of Algal Biology Institute of HydrobiologyChinese Academy of SciencesWuhan 430072China Yangtze River Basin ecological environment monitoring and Scientific Research center Yangtze River Basin Ecological Environment Supervision and Administration BureauMinistry of Ecological EnvironmentWuhan 430072China

Phyllosphere algae are common in tropical rainforests,forming visible biofilms or spots on plant leaf ***,knowledge of phyllosphere algal diversity and the environmental factors that drive that diversity is *** aim of this study is to identify the environmental factors that drive phyllosphere algal community composition and diversity in *** this purpose,we used single molecule real-time sequencing of full-length 18S rDNA to characterize the composition of phyllosphere microalgal communities growing on four host tree species(Ficus tikoua,Caryota mitis,Arenga pinnata,and Musa acuminata) common to three types of forest over four months at the Xishuangbanna Tropical Botanical Garden,Yunnan province,*** 18S rDNA sequences revealed that the green algae orders Watanabeales and Trentepohliales were dominant in almost all algal communities and that phyllosphere algal species richness and biomass were lower in planted forest than in primeval and reserve *** addition,algal community composition differed significantly between planted forest and primeval *** also found that algal communities were affected by soluble reactive phosphorous,total nitrogen,and ammonium *** findings indicate that algal community structure is significantly related to forest type and host tree ***,this study is the first to identify environmental factors that affect phyllosphere algal communities,significantly contributing to future taxonomic research,especially for the green algae orders Watanabeales and *** research also serves as an important reference for molecular diversity analysis of algae in other specific habitats,such as epiphytic algae and soil algae.

关键词： Full-length 18S rDNA sequences Cryptic diversity environmental factors High-throughput sequence Phyllosphere algae Tropical rainforest

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Effects of the conversion of natural tropical rainforest to monoculture rubber plantations on soil hydrological processes

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Journal of Plant Ecology 2024年第2期17卷 122-133页

作者： Qiaoyan Chen Ruiyu Fu Siyuan Cheng Dong Qiao Zhongmin Hu Zijia Zhang Licong Dai Hainan Baoting Tropical Rainforest Ecosystem Observation and Research Station School of Ecology and EnvironmentHainan UniversityHaikou 570228China center for Eco-environment Restoration Engineering of Hainan province Hainan UniversityHaikou 570228China Hainan ecological environment monitoring center Haikou 570100China

Rubber plantations have increased signifcantly under unprecedented economic growth in tropical areas,which leads to soil degradation and thereby alters soil hydrological ***,our understanding of how forest conversion affects soil hydrological processes remains ***,we collected soil samples from secondary forests(SF)and rubber plantations(RP)to determine the soil hydrological *** found the topsoil(0-20 cm)water retention in SF was higher than that of RP but displayed the contrast pattern in a deeper soil layer(20-60 cm).Meanwhile,the soil infltration rates among the two vegetation types decreased signifcantly with infltration time,with higher stable soil infltration rates in SF than those in ***,soil properties were also impacted by the forest conversion,such as the topsoil capillary porosity(CP)and total porosity(TP)in SF were higher than those of RP but contrasted in a deep soil *** comparison,the topsoil bulk density(BD)in SF was lower than that of RP,but contrasted in the deep soil layer and reached a signifcant level in the 0-10 and 40-50 cm(P<0.05).Overall,the soil water retention was mainly determined by the CP,which could explain 31.56%of the total variance in soil water retention,followed by TP(26.57%)and soil BD(26.47%),whereas soil texture exerts a weak effect on soil water ***,we can conclude that the conversion of tropical rainforest into rubber plantations may accelerate soil erosion owing to its lower topsoil water retention and soil infltration rates.

关键词： soil water retention soil infltration soil physicochemical properties rubber plantations secondary forest

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Cooling and wetting of soil decelerated ground freezingethawing processes of the active layer in Xing'an permafrost regions in Northeast China

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Advances in Climate Change Research 2023年第1期14卷 126-135页

作者： Bo-Quan LU Shu-Ying ZANG Li-Quan SONG Li SUN Miao LI Di BING Heilongjiang province Key Laboratory of Geographical environment monitoring and Spatial Information Service in Cold Regions Harbin Normal UniversityHarbin 150025China Heilongjiang province Collaborative Innovation center of Cold Region ecological Safety Harbin 150025China

The accelerated or decelerated freezingethawing processes of the active layer in Xing'an permafrost regions are crucial for the protection of *** better understand the freezingethawing processes of the active layer and its driving factors,according to the observation from 2017 to 2020 of soil temperature and water content in the active layer of forest and peatland in two representative hemiboreal ecosystems in the Da Xing'anling Mountains,Northeast China,the study explored in detail the effects of climatic conditions and local factors on the hydrothermal and freezingethawing processes of active layer *** results showed that during the freezingethawing cycles of 2017-2020,freezing and thawing start times in the peatland and forest ecosystems soils were generally delayed,and it took longer for the active layer soil to completely thaw than to *** annual average soil temperature in the peatland's active layer(5-80 cm)was 0.7-2.0℃ lower than that in the forest,and the annual average soil moisture content on the peatland was 5.5%-26.7%higher than that in the *** with the forest ecosystem soils,the ground surface freezing time of the peatland was delayed by 3e10 d,and the freezing rate decreased by 1.1-1.5 cm d1,while the beginning time of thawing was advanced by 22-27 d,and the thawing rate decreased by 1.3-1.4 cm d^(-1).In the process of decreasing soil temperature and increasing soil moisture content,the freezing and thawing rate of the active layer would be reduced,decelerating the freezingethawing processes of the active layer in the process of decreasing soil temperature and increasing soil moisture *** results provide the key original data for studying the formation and evolution of active layer and permafrost in the Xing'an permafrost regions in Northeast China and can be used to validate the prediction of ecosystem succession under the combined influences of climate change and permafrost degradation.

关键词： Freezingethawing processes Hydrothermal dynamics Active layer Hemiboreal ecosystems Xing'an permafrost

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Detecting surface freeze/thaw states in Northeast China with passive microwave data using an improved standard deviation method

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Advances in Climate Change Research 2023年第2期14卷 190-199页

作者： Hao-Ran MAN Yang XIAO Shu-Ying ZANG Miao LI Xing-Feng DONG Heilongjiang province Key Laboratory of Geographical environment monitoring and Spatial Information Service in Cold Regions Harbin Normal UniversityHarbin 150025China Heilongjiang province Collaborative Innovation center of Cold Region ecological Safety Harbin 150025China

Passive microwave remote sensing datasets are widely used to observe surface freeze/thaw(F/T)***,current algorithms are highly affected by snow cover and complex land cover types,compromising their ***,this study proposes an improved algorithm for daytime detection of diurnal F/T states by using Advanced Microwave Scanning Radiometer 2 *** the daytime F/T discrimination algorithm,a microwave spectral gradient index is applied to divide the surface into snow-covered and snow-free *** the snow-free area,the surface temperature index is optimised to improve the accuracy of the standard deviation method(SDM)in evaluating the accuracy of the F/T *** the nighttime dataset,the microwave standard deviation index difference values between day and night are used to detect the F/T states based on the daytime *** accuracy of the improved algorithm reaches 88.6%and 84.5%in the daytime and at nighttime,*** with the SDM,the accuracy is improved by 10.2%in the daytime and 5.4%at *** results demonstrate that the proposed model is able to effectively distinguish the F/T states of snow-covered *** the surface temperature index can significantly improve the accuracy of the *** results reveal that the proposed surface F/T detection algorithm can be applied to regions with complex land cover types.

关键词： Microwave remote sensing Surface F/T algorithm improvement Seasonal snow areas Classification Northeast China

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Assessing the Connectivity of a Regional Fractured Aquifer Based on a Hydraulic Conductivity Field Reversed by Multi-Well Pumping Tests and Numerical Groundwater Flow Modeling

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Journal of Earth Science 2023年第6期34卷 1926-1939页

作者： Jingjing Lin Rui Ma Ziyong Sun Liansong Tang School of environmental Studies State Key Laboratory of Biogeology and Environmental GeologyChina University of GeosciencesWuhan 430078China Yangtze River Basin ecological environment monitoring and Scientific Research center Yangtze River Basin Ecological Environment Supervision and Administration BureauMinistry of Ecological EnvironmentWuhan 430010China

Aquifer connectivity could greatly affect groundwater flow and further control the contaminant transport in fractured ***,assessing connectivity of fractured aquifer at regional scales is still a challenge because such connectivity is difficult to be measured *** study proposes a framework for assessing connectivity of a fractured aquifer,with Qitaihe area,Heilongjiang province,northeastern China as an illustrating study *** 3-D finite difference numerical models were established to interpret the results of three multi-well pumping tests and inversely estimate the distribution of hydraulic conductivity(K)in the fractured aquifer.A static connectivity metric of the minimum hydraulic resistance(MHR)was calculated,based on the optimized K-field,to evaluate the hydraulic connectivity in the aquifer,and the corresponding least resistance paths(LRPs)were *** results indicate a better horizontal connectivity in the fractured aquifer in the northeastern and middle parts than in the southwestern part of the study *** identified LRP indicated that the preferential flow channels at regional scales were controlled mainly by aquifer connectivity instead of local high-K *** results of this study can provide a method for aquifer connectivity estimation at regional scales.

关键词： numerical modeling aquifer connectivity groundwater flow hydraulic conductivity minimum hydraulic resistance least resistance paths

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