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Effects of Fe3+ and Ca2+ on sorption of phenanthrene by Humin in karst soil,Southwest China

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Acta Geochimica 2023年第1期42卷 125-135页

作者： Xianjin An Wei Li Xinyue Di Jiacheng Lan School of karst Science Guizhou Normal University550001 GuiyangChina State Engineering Technology Institute for karst Desertifi cation Control 550001 GuiyangChina Guiyang University 550005 GuiyangChina School of Geography and Environmental Engineering Gannan Normal University341000 GanzhouChina

Humin(HM) is the main organic matter component to af fect the migration and transformation of polycyclic aromatic hydrocarbons(PAHs) in soil. The study on infl uence of the morphology change of inorganic ions on the adsorption of PAHs in soil and its organic matter is still rare at microscopic scale. In this paper, yellow soil humin(YS-HM) and lime soil humin(LS-HM) were chosen as samples, then Fe^(3+) and Ca^(2+) were added into samples to facilitate the precipitation by changing the existing conditions of ions, and the mechanism by which inorganic precipitation changed adsorption capacity of karst soil was analyzed from the microscopic scale. The results showed that the adsorption capacity of HM reduced with the inorganic precipitation increasing. The precipitation of Ca^(2+)and Fe^(3+) both reduced the adsorption capacity of YS-HM and LS-HM by 61.71% and 71.83% on average, respectively. The results of scanning electron microscope-energy dispersive spectrometry(SEM-EDS) and pore analysis showed that the HM porosity decreased after formation of Ca^(2+) and Fe^(3+) precipitation. According to the value of Freundlich parameter n, it may be because the precipitation or colloid of Ca^(2+) and Fe^(3+) fi lled micropores and covers high-energy adsorption sites of the HM. This research provides theoretical support for studying the PAHs migration and bioavailability of Calcium-rich in karst soil.

关键词： Inorganic ions Humin Phenanthrene Adsorption Soil karst

Aquatic community structure and stream habitat in a karst agricultural landscape

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Ecological Processes 2022年第1期11卷 155-170页

作者： Neal D.Mundahl Erik D.Mundahl Department of Biology and Southeastern Minnesota Water Resources Center Winona State UniversityWinonaMN 55987USA Mundahl Nordic Services Glennallen/McCarthyP.O.Box MXYAlaska 99588USA

Background:Watersheds dominated by agriculture often have significant,negative impacts on local stream habitats and fauna.Our study examined stream biota and habitats within an entire stream in a karst agricultural landscape to determine if several decades of watershed conservation and management had reversed the severe degradation caused by poor land use and catastrophic soil erosion during the 1920s and 1930s.Results:Fish communities and stream habitats were degraded at over half of the 22 stream sites examined,and benthic macroinvertebrate communities were mostly poor throughout the entire stream.Poor fish communities were associated with missing or narrow riparian buffers,high percent fine sediments,high embeddedness of coarse sub-strates,and homogeneous run habitat.Invertebrate communities were dominated by filter-feeding taxa and those adapted to life on or within fine sediments.Stream sites with wide buffers and influenced by groundwater springs had higher fish community integrity and good to excellent instream habitat.Conclusions:Our results suggest that wide riparian buffers and karstic springs may have allowed recovery of some stream reaches,but more extensive buffers and additional soil conservation practices in upland areas likely are necessary to protect most stream segments and their biota from on-going agricultural activities.New state stream buffer laws instituted after this study resulted in establishment of vegetated buffers at all study sites,which may lead to improved stream habitat and biotic communities in future years.Benthic invertebrate community improvement also may require translocation of sensitive taxa from nearby watersheds due to limited dispersal abilities of many species currently absent from the study stream.Increased frequency and intensity of storm events and flooding may hinder future recovery of stream habitats and biota.

关键词： Agricultural stream Fish Macroinvertebrates Stream habitats karst

Effects of rainfall and rocky desertification on soil erosion in karst area of Southwest China

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Journal of Mountain Science 2022年第11期19卷 3118-3130页

作者： PAN Li-dong LI Rui SHU Dong-cai ZHAO Li-na CHEN Mei JING Jun School of karst Science Guizhou Normal UniversityGuiyang 550001China State Engineering Technology Institute for karst Desertification Control Guiyang 550001China College of Resources and Environment Southwest UniversityChongqing 400715China Guizhou Hydrology and Water Resources Bureau Guiyang 550002China

Monitoring and evaluating the evolution of rocky desertification timely and studying the characteristics of soil erosion under different rainfall patterns are of great scientific significance for regional soil and water conservation,rocky desertification control and ecological environment construction.Four periods of remote sensing image data from 2005 to 2020 were selected to study the evolution characteristics of rocky desertification and its impact on soil erosion in the controlled boundary area of Shibantang hydrological station of Yeji River Watershed,Guizhou Province,China.According to the 408 erosive rainfall events,the soil erosion under different rainfall patterns in the watershed was analyzed.The results showed that:erosive rainfall events in the study area were mainly pattern A,accounting for 57.4%of the total rainfall events;the second was pattern B,accounting for 28.9%of the total rainfall events;the rainfall pattern of C occurred occasionally.Among them,pattern A was the main rainfall pattern leading to soil and water loss and had the largest contribution rate to soil erosion in the watershed.From 2005 to 2020,the area of rocky desertification showed a decreasing trend,accounting for 72.2%from 87.9%.Spatially,rocky desertification has mainly concentrated in the middle south of the watershed since 2010,while the rocky desertification mainly concentrated in the middle and north before 2010.The effects of different grades of rocky desertification on soil erosion were different,and the soil erosion modulus in areas with the medium,severe and extremely severe rocky desertification was generally small.The soil erosion modulus estimated by the RUSLE(Revised Universal Soil Loss Equation)model was still much higher than that calculated by the data measured by the hydrological monitoring station.Therefore,the application of the RUSLE model in karst area needs to be further modified.These results can provide reference for rocky desertification control,soil erosion control and fragile ecosystem restoration in k

关键词： Erosive rainfall Rocky desertification Spatial-temporal evolution Soil erosion karst

Determining nitrogen fate by hydrological pathways and impact on carbonate weathering in an agricultural karst watershed

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International Soil and Water Conservation Research 2023年第2期11卷 327-338页

作者： Zhuo Hao Yang Gao Yang Yang Qingwen Zhang Agricultural Clean Watershed Research Group Institute of Environment and Sustainable Development in AgricultureCAASBeijing100081China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchCAsBejing10011 China Sierra Nevada Research Institute University of CalifomiaMercedCA95344USA

Identifying the nitrogen(N)fate is complicated and a great challenge in karst watersheds because of the co-existence of natural pools and anthropogenic sources.The objective of the study was to use stable isotopic composition of dual-isotope(δ^(15)NNitrate and δ^(18)O_(Nitrate))and LOADEST model approaches to trace N sources,pathways in karst watershed.The study was conducted in the Houzhai watershed,which is a typical agricultural karst watershed from July 2016 to August 2018,to reveal the N fate and the coupled carbon(C)-N processes occurring in the riverine-watershed with agricultural activities.We found that the wet deposition of total nitrogen(TN)flux was 33.50 kg hm^(-2)·a^(-1)and dissolved nitrogen(DN)flux was 21.66 kg hm^(-2)·a^(-1).The DN runoff loss was 2.10×10^(5)kg·a^(-1)and the loss of DN during the wet season accounted for 95.4%over a year.In the wet season,NO_(3)^(-)-N daily efflux was 977.62±516.66 kg ha^(-1)·day^(-1)and 248.77±57.83 kg ha^(-1)·day^(-1)in the dry season.The NH_(4)^(+)-N efflux was 29.17±10.50 kg ha^(-1)·day^(-1)and 4.42±3.07 kg ha^(-1)·day^(-1)in the wet and dry seasons,respectively.The main form output load of N was NO_(3)^(-)-N which was more than 30 times as much as NH_(4)^(+)-N output loss.The NO_(3)^(-)N caused by rainfall contributed11.82%-53.61%to the export load.Nitrate from soil contributed over 94%of the N to Houzhai river caused by N leaching.In addition,manure and farmland soil were the main sources of groundwater in the Houzhai watersheds,the contribution rates were 25.9%and 22.5%.The chemical N fertilizers affected carbonate weathering strongly,and the HCO_(3)^(-) flux caused by nitrifi-cation due to N fertilizers application in soil accounted for 23.5%of the entire watershed.This study suggested that carbonate weathering may be influenced by nitrogen nitrification in the karst watershed.

关键词： karst Agricultural watershed Hydrological pathway Nitrogen Carbonate weathering

A new species of Bostrychus (Gobiiformes: Eleotridae) from the East China Sea

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Zoological Research(Diversity and Conservation) 2024年第1期1卷 82-85页

作者： Rong-Rong Zhang Kuan Yang Dian Luo Shao-Xiong Ding College of Ocean and Earth Sciences Xiamen UniversityXiamenFujian 361102China

DEAR EDITOR,Bostrychus,a genus in the family Eleotridae of the order Gobiiformes,was first established by Lacepède in 1801(Buffon,1801).Bostrychus currently contains seven recognized species,including two recent additions(B.microphthalmos and B.scalaris)described in 2005(Hoese&Kottelat,2005)and 2008(Larson,2008),respectively.The natural range of Bostrychus species extends from East Asia to Australia,with the exception of B.africanus,Steindachner,1879,which is distributed in West Africa(Herre,1946).Among the recognized species,B.sinensis,B.zonatus,and B.africanus are relatively widespread,inhabiting diverse areas from estuaries to freshwater streams,while B.scalaris is only found at a single mangrove site in the Selangor State of Malaysia(Larson,2008).The remaining three species exhibit a high degree of habitat specialization and are highly localized(Hoese&Kottelat,2005):B.microphthalmos inhabits a cave stream in the Maros karst of southern Sulawesi,B.aruensis is confined to freshwater environments in the Aru Islands of Indonesia,and B.strigogenys is found only in freshwater areas in southern Papua New Guinea and Irian Jaya.

关键词： East karst environments

Inland-coastal demographic transformations in a karst area:a case study of the surroundings of Krka National Park(Croatia)

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Journal of Mountain Science 2022年第2期19卷 305-321页

作者： TELBISZ Tamas RADELJAK KAUFMANN Petra BOCIC Neve Department of Physical Geography Eotvos Lorand UniversityPazmany Peter setany 1/CBudapest 1117Hungary Department of Geography Faculty of ScienceUniversity of ZagrebMarulicev trg 19/IIZagreb 10000Croatia

According to geographic possibilism,environment does not determine socio-economic development.However,the environment sets certain constraints and limitations for development.How do natural settings influence population dynamics?In this study,we examine this question using the example of?ibenik-Knin County,which includes Krka National Park(NP)with a GIS-based statistical approach.The following parameters represent natural factors:elevation,slope,distance from water,and proportion of karst areas.In addition,distance from Krka NP was also added as an independent seminatural factor(despite the fact that it is a social construction).The dependent social parameters are population density for selected historical dates,population change,year of maximum population,natural increase,migration,and age index.The analysis units are the 199 settlements found in the county,and the 20 local administrative units(LAU2).The study period can be divided into five phases:from the first census in 1857 to 1921,there was a slow increase in most settlements;then a relatively constant phase up to 1961(some settlements began shrinking in this period);a slow decrease until 1991;arapid decrease during the next decade;and relative stabilisation to present day.These processes were also accompanied by significant inner and outer migrations.As for the relationships between natural and demographic factors,we found that although the coastal-inland area dichotomy is dominant in the study area,elevation has the highest correlation with most population parameters.However,distance from water is also significantly correlated with population change and migration in certain periods.In the inland areas,there are statistically significant differences between the demographic processes of fully-karstic and partially-karstic areas,while in the coastal zone,the karst effect is overshadowed by other social processes.The impact of Krka NP on the demographic characteristics of the surrounding settlements was statistically not detectable.Our final conclusion is tha

关键词： Geographic possibilism karst National park Population density Migration

Filling of dolines with aeolian sediments in the high-mountain karst of the Dinarides(Mt.Durmitor,Montenegro)

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Journal of Mountain Science 2022年第7期19卷 1886-1900页

作者： DJUROVIC Mirela GAJIC Violeta DJUROVIC Predrag University of Belgrade Faculty of PhilosophyDepartment of ArcheologyCika Ljubina 18-20Belgrade11000Serbia University of Belgrade Faculty of Mining and GeologyDepartment of MineralogyCrystallographyPetrology and GeochemistryDjusina 7Belgrade11000Serbia University of Belgrade Faculty of GeographyStudentski trg 3/ⅢBelgrade11000Serbia

Filling of dolines with aeolian sediments,one of the less frequently described ways in which they are filled,is analysed in the present study on an example of a doline in the high-mountain karst of the Dinarides.There is a series of deep dolines on a broad ridge(about 2450 m a.s.l.)on Mt.Durmitor(Montenegro)in the southeastern part of the Dinarides.The accumulation of very fine-grained sand that almost completely fills one of the dolines was analysed.More than 99% of the accumulation was found to be composed of well-sorted quartz grains with an average size of 89μm and no vertical differences in granulometric or textural characteristics.With respect to mineral composition,the accumulation differs significantly from that prevalent in this part of the Dinarides,in which different kinds of carbonate rocks are dominant.The conducted analyses indicated an aeolian origin of the sediments.Significant aridification that began in the Middle Holocene made the area of North Africa a source of sediments that were transported by the aeolian process to neighbouring regions.Geomorphological-sedimentological research on Mt.Durmitor and earlier investigations of the wider Mediterranean region indicate that dolines in highmountain karst can be filled with aeolian sediments.The sediments originated from territory of the northern Sahara,and the filling occurred in the Late Holocene,at the close of the African humid period.The present study shows that apart from the influence of local factors,regional geomorphological processes such as aeolian transport can also exert significant influence on the filling of dolines.It also indicates a high intensity and strongly expressed dynamics of aeolian sediment transport from the territory of Africa to this part of Southern Europe.

关键词： Doline Filling Aeolian sediments karst Dinarides Montenegro

Scaling and clogging treatment of aging tunnel drainage pipes in karst areas using eco-friendly acid agent

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第4期15卷 896-910页

作者： Zhipeng Xu Xuemei Wang Chunfang Zhang Dejian Zeng Changwu Liu College of Water Resource and Hydropower Sichuan UniversityChengdu610065China State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan UniversityChengdu610065China College of Chemistry Sichuan UniversityChengdu610065China College of Chemistry and Environment Science Hebei UniversityBaoding071002China China Railway Eryuan Engineering Group Co.Ltd. Chengdu610031China

In karst areas,the drainage pipes of aging tunnels are prone to be clogged by precipitated carbonates,resulting in lining cracking and tunnel leaking.As a result,not only the driving safety will be deteriorated,but also the water pressure on the lining might also be elevated significantly.For the structural stability and service lifespan of old tunnels,it is of great importance to remove these precipitated carbonates in time.Traditional treatment methods are often destructive to some extent or not efficient enough.This study aims to experimentally develop an eco-friendly acid-based chemical cleaning method to remove carbonate precipitations efficiently.The proposed chemical cleaning agent is an aqueous solution with strong acidity,consisting of sulfamic acid,water,and additives.The factors affecting the cleaning efficiency include the acid solubility,temperature and flow rate of the cleaning agent,as well as additives.Elevating the solution temperature to 50C or a flow rate of no less than 0.2 m/s can improve cleaning efficiency.Although the salt effect cannot work,1 wt%of polymaleic acid as a surfactant could further promote the cleaning rate.The cleaning efficiency will increase with the flow rate in a power function.The relatively low flow rate that improves the cleaning rate considerably can avoid highpressure-induced mechanical damage to tunnel drainpipes.The waste could be easily treated to acceptable levels using commercial sewage treatment products and can also be recycled in agriculture.With the chemical cleaning,the water pressure at the arch springing of the lining will reduce with the increased radius of transverse drainpipes in a power function.The proposed acid-based cleaning method,which is highly efficient,non-or low-destructive to aging tunnels,sufficiently safe for humans,and friendly enough to the environment,will offer a promising alternative to remove the precipitated carbonates in tunnel drainpipes efficiently.

关键词： Clogging Scaling Carbonate precipitation Acid treatment Water pressure on the lining Aging tunnel karst

Historical development of karst evergreen broadleaved forests in East Asia has shaped the evolution of a hemiparasitic genus Brandisia(Orobanchaceae)

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Plant Diversity 2023年第5期45卷 501-512页

作者： Zhe Chen Zhuo Zhou Ze-Min Guo Truong Van Do Hang Sun Yang Niu CAS Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of BotanyChinese Academy of Sciences132 Lanhei RoadKunming 650201YunnanChina University of Chinese Academy of Sciences Beijing 100049China Vietnam National Museum of Nature Vietnam Academy of Science and Technology18 Hoang Quoc VietCau Giay 10000HanoiVietnam Graduate University of Science and Technology Vietnam Academy of Science and Technology18 Hoang Quoc VietCau Giay 10000HanoiVietnam

Brandisia is a shrubby genus of about eight species distributed basically in East Asian evergreen broadleaved forests(EBLFs),with distribution centers in the karst regions of Yunnan,Guizhou,and Guangxi in southwestern China.Based on the hemiparasitic and more or less liana habits of this genus,we hypothesized that its evolution and distribution were shaped by the development of EBLFs there.To test our hypothesis,the most comprehensive phylogenies of Brandisia hitherto were constructed based on plastome and nuclear loci(nrDNA,PHYA and PHYB);then divergence time and ancestral areas were inferred using the combined nuclear loci dataset.Phylogenetic analyses reconfirmed that Brandisia is a member of Orobanchaceae,with unstable placements caused by nuclear-plastid incongruences.Within Brandisia,three major clades were well supported,corresponding to the three subgenera based on morphology.Brandisia was inferred to have originated in the early Oligocene(32.69 Mya)in the Eastern Himalayas-SW China,followed by diversification in the early Miocene(19.45 Mya)in karst EBLFs.The differentiation dates of Brandisia were consistent with the origin of keystone species of EBLFs in this region(e.g.,Fagaceae,Lauraceae,Theaceae,and Magnoliaceae)and the colonization of other characteristic groups(e.g.,Gesneriaceae and Mahonia).These findings indicate that the distribution and evolution of Brandisia were facilitated by the rise of the karst EBLFs in East Asia.In addition,the woody and parasitic habits,and pollination characteristics of Brandisia may also be the important factors affecting its speciation and dispersal.

关键词： Biogeography Brandisia Evergreen broadleaved forests(EBLFs) karst Orobanchaceae Phylogeny