The change of frozen soil environment is evaluated by permafrost thermal stability, thermal thaw sensibility and surface landscape stability and the quantitatively evaluating model of frozen soil environment is propos...The change of frozen soil environment is evaluated by permafrost thermal stability, thermal thaw sensibility and surface landscape stability and the quantitatively evaluating model of frozen soil environment is proposed in this paper. The evaluating model of frozen soil environment is calculated by 28 ground temperature measurements along Qinghai-Xizang Highway. The relationships of thermal thaw sensibility and freezing and thawing processes and seasonally thawing depth, thermal stability and permafrost table temperature, mean annual ground temperature and seasonally thawing depth, and surface landscape stability and freezing and thawing hazards and their forming possibility are analyzed. The results show that thermal stability, thermal thaw sensibility and surface landscape stability can be used to evaluate and predict the change of frozen soil environment under human engineering action.展开更多
To illuminate the spatio-temporal variation characteristics and geochemical driving mechanism of soil pH in the Nenjiang River Basin,the National Multi-objective Regional Geochemical Survey data of topsoil,the Second ...To illuminate the spatio-temporal variation characteristics and geochemical driving mechanism of soil pH in the Nenjiang River Basin,the National Multi-objective Regional Geochemical Survey data of topsoil,the Second National Soil Survey data and Normalized Difference Vegetation Index(NDVI)were analyzed.The areas of neutral and alkaline soil decreased by 21100 km^(2)and 30500 km^(2),respectively,while that of strongly alkaline,extremely alkaline,and strongly acidic soil increased by 19600 km^(2),18200 km^(2),and 15500 km^(2),respectively,during the past 30 years.NDVI decreased with the increase of soil pH when soil pH>8.0,and it was reversed when soil pH<5.0.There were significant differences in soil pH with various surface cover types,which showed an ascending order:Arbor<reed<maize<rice<high and medium-covered meadow<low-covered meadow<Puccinellia.The weathering products of minerals rich in K_(2)O,Na_(2)O,CaO,and MgO entered into the low plain and were enriched in different parts by water transportation and lake deposition,while Fe and Al remained in the low hilly areas,which was the geochemical driving mechanism.The results of this study will provide scientific basis for making scientific and rational decisions on soil acidification and salinization.展开更多
Oil spills have become a serious problem in cold environments with the ever-increasing resource exploitation, transportation, storage, and accidental leakage of oil. Several techniques, including physical, chemical, a...Oil spills have become a serious problem in cold environments with the ever-increasing resource exploitation, transportation, storage, and accidental leakage of oil. Several techniques, including physical, chemical, and biological methods, are used to recover spilled oil from the environment. Bioremediation is a promising option for remediation since it is effective and economic in removing oil with less undue environmental damages. However, it is a relatively slow process in cold regions and the degree of success depends on a number of factors, including the properties and fate of oil spilled in cold environments, and the major microbial and environmental limitations of bioremediation. The microbial factors include bioavailability of hydrocarbons, mass transfer through the cell membrane, and metabolic limitations. As for the environmental limitations in the cold regions, the emphasis is on soil temperatures, freeze-thaw processes, oxygen and nutrients availability, toxicity, and electron acceptors. There have been several cases of success in the polar regions, particularly in the Arctic and sub-Arctic regions. However, the challenges and constraints for bioremediation in cold environments remain large.展开更多
【目的】通过检索分析根系构型相关研究数据库,以期为进一步研究提供新视野新思路。【方法】基于Web of Science数据库收录2011—2020年有关根系构型研究的相关文献753篇,采用Citespace信息可视化手段对根系构型研究年发文量、研究国家...【目的】通过检索分析根系构型相关研究数据库,以期为进一步研究提供新视野新思路。【方法】基于Web of Science数据库收录2011—2020年有关根系构型研究的相关文献753篇,采用Citespace信息可视化手段对根系构型研究年发文量、研究国家与机构、关键词、研究主旨进行分析,旨在归纳当前研究热点与趋势,总结研究现状,展望未来研究方向。【结果】结果表明,2011—2020年10 a间根系构型文献发表量呈快速上升趋势;主要学科涉及植物科学、农学、土壤科学。中国在该研究发文量占全球总的28.69%;主要关键词为根系生理、根系构型、植物类型等3个聚类,热点关键词为“干旱”和“耐受性”;研究方向可分为探测技术、环境影响、根系生长特性、自身调控等4个聚类,其中环境影响为热点研究方向。研究方向自探测技术和根系生长特性(2011—2013年)、植株自身调控及根系生长特性(2014—2017年)至环境影响(2018—2020年)逐步过渡。【结论】鉴于目前研究多集中于根系本身或根系周围环境对土壤微生物、土壤水分生态及土壤养分生态的影响,推断地上部响应根系构型变化以适应全球气候变化可能会成为未来研究热点。展开更多
基金This work was supported by the NSFC (Grant No. 90102006) the Knowledge Innovation Program of the Chinese Academy of Sciences (KZCX-SW-04)+1 种基金 the Creative Project of CAREER] (Grant Nos. CACX210047 and CACX210086) Post Doctoral Fund of Nanjing Uni
文摘The change of frozen soil environment is evaluated by permafrost thermal stability, thermal thaw sensibility and surface landscape stability and the quantitatively evaluating model of frozen soil environment is proposed in this paper. The evaluating model of frozen soil environment is calculated by 28 ground temperature measurements along Qinghai-Xizang Highway. The relationships of thermal thaw sensibility and freezing and thawing processes and seasonally thawing depth, thermal stability and permafrost table temperature, mean annual ground temperature and seasonally thawing depth, and surface landscape stability and freezing and thawing hazards and their forming possibility are analyzed. The results show that thermal stability, thermal thaw sensibility and surface landscape stability can be used to evaluate and predict the change of frozen soil environment under human engineering action.
基金supported by China Geological Survey(DD20230554,DD20230089)the Strategic Priority Research Program of the Chinese Academy of Science(XDA28020302)the funding project of Northeast Geological S&T Innovation Center of China Geological Survey(QCJJ2022-40).
文摘To illuminate the spatio-temporal variation characteristics and geochemical driving mechanism of soil pH in the Nenjiang River Basin,the National Multi-objective Regional Geochemical Survey data of topsoil,the Second National Soil Survey data and Normalized Difference Vegetation Index(NDVI)were analyzed.The areas of neutral and alkaline soil decreased by 21100 km^(2)and 30500 km^(2),respectively,while that of strongly alkaline,extremely alkaline,and strongly acidic soil increased by 19600 km^(2),18200 km^(2),and 15500 km^(2),respectively,during the past 30 years.NDVI decreased with the increase of soil pH when soil pH>8.0,and it was reversed when soil pH<5.0.There were significant differences in soil pH with various surface cover types,which showed an ascending order:Arbor<reed<maize<rice<high and medium-covered meadow<low-covered meadow<Puccinellia.The weathering products of minerals rich in K_(2)O,Na_(2)O,CaO,and MgO entered into the low plain and were enriched in different parts by water transportation and lake deposition,while Fe and Al remained in the low hilly areas,which was the geochemical driving mechanism.The results of this study will provide scientific basis for making scientific and rational decisions on soil acidification and salinization.
基金Project supported by the 100 Talents Program of the Chinese Academy of Sciences (No.2004407).
文摘Oil spills have become a serious problem in cold environments with the ever-increasing resource exploitation, transportation, storage, and accidental leakage of oil. Several techniques, including physical, chemical, and biological methods, are used to recover spilled oil from the environment. Bioremediation is a promising option for remediation since it is effective and economic in removing oil with less undue environmental damages. However, it is a relatively slow process in cold regions and the degree of success depends on a number of factors, including the properties and fate of oil spilled in cold environments, and the major microbial and environmental limitations of bioremediation. The microbial factors include bioavailability of hydrocarbons, mass transfer through the cell membrane, and metabolic limitations. As for the environmental limitations in the cold regions, the emphasis is on soil temperatures, freeze-thaw processes, oxygen and nutrients availability, toxicity, and electron acceptors. There have been several cases of success in the polar regions, particularly in the Arctic and sub-Arctic regions. However, the challenges and constraints for bioremediation in cold environments remain large.
文摘【目的】通过检索分析根系构型相关研究数据库,以期为进一步研究提供新视野新思路。【方法】基于Web of Science数据库收录2011—2020年有关根系构型研究的相关文献753篇,采用Citespace信息可视化手段对根系构型研究年发文量、研究国家与机构、关键词、研究主旨进行分析,旨在归纳当前研究热点与趋势,总结研究现状,展望未来研究方向。【结果】结果表明,2011—2020年10 a间根系构型文献发表量呈快速上升趋势;主要学科涉及植物科学、农学、土壤科学。中国在该研究发文量占全球总的28.69%;主要关键词为根系生理、根系构型、植物类型等3个聚类,热点关键词为“干旱”和“耐受性”;研究方向可分为探测技术、环境影响、根系生长特性、自身调控等4个聚类,其中环境影响为热点研究方向。研究方向自探测技术和根系生长特性(2011—2013年)、植株自身调控及根系生长特性(2014—2017年)至环境影响(2018—2020年)逐步过渡。【结论】鉴于目前研究多集中于根系本身或根系周围环境对土壤微生物、土壤水分生态及土壤养分生态的影响,推断地上部响应根系构型变化以适应全球气候变化可能会成为未来研究热点。
