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Symbiosis of Marshes and Permafrost in Da and Xiao Hinggan Mountains in Northeastern China

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Chinese Geographical Science 2008年第1期18卷 62-69页

作者： JIN Huijun SUN Guangyou YU Shaopeng JIN Rui he ruixia State Key Laboratory of Frozen Soils Engineering Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China Northeast Institute of Geography and Agroecology Chinese Academy of Sciences Changchun 130012 China Department of Geography Harbin College Harbin 150086 China

Recently, the degradation of permafrost and marsh environments in the Da and Xiao Hinggan Mountains has become a great concern as more human activities and pronounced climate warming were observed during the past 30 years and projected for the near future. The distr/bution patterns and development mechanisms of the permafrost and marshes have been examined both in theories and in field observations, in order to better understand the symbiosis of permafrost and marshes. The permafrost and marshes in the Da and Xiao Hinggan Mountains display discernible zonations in latitude and elevation. The marsh vegetation canopy, litter and peat soil have good thermal insulation properties for the underlying permafrost, resulting in a thermal offset of 3 ℃ to 4℃ and subsequently suppressing soil temperature. In addition, the much higher thermal conductivity of frozen and ice-rich peat in the active layer is conducive to the development or in favor of the protection of permafrost due to the semi-conductor properties of the soils overlying the permafrost. On the other hand, because permafrost is almost impervious, the osmosis of water in marsh soils can be effectively reduced, timely providing water supplies for helophytes growth or germination in spring. In the Da and Xiao Hinggan Mountains, the permafrost degradation has been accelerating due to the marked climate warming, ever increasing human activities, and the resultant eco-environmental changes. Since the permafrost and marsh environments are symbiotic and interdependent, they need to be managed or protected in a well-coordinated and integrated way.

关键词： marsh permafrost symbiosis thermal offset active layer Da and Xiao Hinggan Mountains

Climate warming over 1961–2019 and impacts on permafrost zonation in Northeast China

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Journal of Forestry Research 2022年第3期33卷 767-788页

作者： Xiaoying Li Huijun Jin Long Sun Hongwei Wang ruixia he Yadong Huang Xiaoli Chang Key Laboratory of Sustainable Forest Ecosystem Management Ministry of EducationSchool of ForestryNortheast Forestry UniversityHarbin150040People’s Republic of China School of Civil Engineering Northeast China Observatory and Research Station of Permafrost Geo-Environment-Ministry of EducationInstitute of Cold-Regions Engineering Science and TechnologyNortheast Forestry UniversityHarbin150040People’s Republic of China Da-Xing’anling Observatory and Research Station of Permafrost Engineering and Environment and State Key Laboratory of Frozen Soils Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou730000People’s Republic of China School of Resource and Environmental and Safety Engineering Hunan University of Science and TechnologyXiangtanHunan411202People’s Republic of China

In boreal forest ecosystems, permafrost and forest types are mutually interdependent;permafrost degradation impacts forest ecosystem structure and functions. The Xing’an permafrost in Northeast China is on the southern margin of the Eastern Asia latitudinal permafrost body. Under a warming climate, permafrost undergoes rapid and extensive degradation. In this study, the frost-number (Fn) model based on air temperatures and ground surface temperatures was used to predict the distribution of the Xing’an permafrost, and, temporal and spatial changes in air and ground-surface temperatures from 1961 to 2019 are analyzed. The results show that Northeast China has experienced a rapid and substantial climate warming over the past 60 years. The rises in mean annual air and mean annual ground-surface temperatures were higher in permafrost zones than those in the seasonal frost zone. The frost numbers of air and ground-surface temperatures were calculated for determining the southern limit of latitudinal permafrost and for permafrost zonation. The southern limits of discontinuous permafrost, sporadic permafrost, and latitudinal permafrost moved northward significantly. According to the air-temperature frost-number criteria for permafrost zoning, compared with that in the 1960s, the extent of Xing’an permafrost in Northeast China had decreased by 40.6% by the 2010s. With an average rate of increase in mean annual air temperatures at 0.03 ℃ a^(−1), the extent of permafrost in Northeast China will decrease to 26.42 × 10^(4) by 2020, 14.69 × 10^(4) by 2040 and to 11.24 × 10^(4) km^(2) by 2050. According to the ground-surface temperature frost-number criteria, the southern limit of latitudinal permafrost was at the 0.463. From the 1960s to the 2010s, the extent of latitudinal permafrost declined significantly. Due to the nature of the ecosystem-protected Xing’an-Baikal permafrost, management and protection (e.g., more prudent and effective forest fire management and proper logging

关键词： Climate warming Permafrost zonation Southern limit of latitudinal permafrost Regional differentiation Mean annual air temperature Mean annual ground surface temperature

Possible controlling factors in the development of seasonal sand wedges on the Ordos Plateau,North China

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Research in Cold and Arid Regions 2021年第2期13卷 167-176页

作者： Hugh MFrenchψ Jef Vandenberghe HuiJun Jin ruixia he Departments of Geography and Earth Sciences University of OttawaOntarioCanadaDepartment of GeographyUniversity of VictoriaBritish ColumbiaCanada Institute of Earth Sciences Vrije Universiteit AmsterdamThe Netherlands School of Civil Engineering Institute of Cold-Regions EngineeringScience and TechnologyNortheast-China Observatory and Research-Station of Permafrost Geo-Environment-Ministry of EducationNortheast Forestry UniversityHarbinHeilongjiang150040China State Key Laboratory of Frozen Soils Engineering and Northwest Institute of Eco-Environment and Resources Chinese Academy of SciencesLanzhouGansu 730000China

Wedge-like structures filled with silty sand penetrate Quaternary fluvial and aeolian sediments and, in places, Tertiary bedrock on the Ordos Plateau, North China. The wedges reflect thermal contraction cracking of either permafrost or seasonal frost during the Late Pleistocene and early Holocene. Wedges of about 1 m in depth form polygonal nets of 2-3 m in diameter(type B). They contrast with wedges of 3-4 m in depth that form polygons of 10-15 m in diameter(type A).This review focuses upon the highly variable size of the inferred polygon nets and discusses the problem of differentiating between seasonally and perennially frozen ground, or between seasonal frost and permafrost.

关键词： frozen ground sand-wedge casts frost fissures thermal contraction cracking seasonal frost cracking desiccation cracking

Prediction of permafrost changes in Northeastern China under a changing climate

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Science China Earth Sciences 2011年第6期54卷 924-935页

作者： WEI Zhi JIN HuiJun ZHANG JianMing YU ShaoPeng HAN XuJun JI YanJun he ruixia CHANG XiaoLi State Key Laboralory of Frozen Soils Engineering Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China Northwest University for Nationalities Lanzhou 730030 China Baiyin Hydraulic Engineering Designing Institute Baiyin 730900 China Laboratory of Remote Sensing and Geospatial Science Cold and Arid Regions Environmental and Engineering Chinese Academy of Sciences Lanzhou 730000 China Gansu Electric Power Design Institute Lanzhou 730050 China

Northeastern China has the second largest expanse of permafrost in China,primarily known as Xing'an-Baikal *** on the southeastern edges of the Eurasian cryolithozone,the permafrost is thermally unstable and ecologically sensitive to external *** combined impacts of climatic,environmental,and anthropogenic changes cause 3-dimensional degradation of the *** predict these changes on the southern limit and ground temperature of permafrost in Northeastern China,an equivalent latitude model (ELM) for the mean annual ground surface temperature (MAGSTs) was proposed,and further improved to take into account of the influences of vegetation and snow-cover based on observational data and using the SHAW *** the finite element method and assuming a climate warming rate of 0.048°C a-1,the ELM was combined with the unsteady-state heat conduction model to simulate permafrost temperatures at present,and to predict those after 50 and 100 *** results indicate that at present,sporadic permafrost occurs in the zones with MAGSTs of 1.5°C or colder,and there would still be a significant presence of permafrost in the zones with the present MAGSTs of 0.5°C or colder after 50 a,and in those of-0.5°C or colder after 100 ***,the total areal extent of permafrost would decrease from 2.57×105 km2 at present to 1.84×105 km2 after 50 a and to 1.29×105 km2 after 100 a,i.e.,a reduction of 28.4% and 49.8% in the permafrost area,*** the permafrost would degrade more substantially in the east than in the *** warming and thinning of permafrost would also *** area of stable permafrost (mean annual ground temperature,or MAGT≤-1.0°C) would decrease from present 1.07×105 to 8.8×104 km2 after 50 a,and further decrease to 5.6×104 km2 after 100 *** a result,the unstable permafrost and seasonally frozen ground would expand,and the southern limit of permafrost would shift significantly *** changes in the permafrost env

关键词： permafrost Northeastern China climate change equivalent latitude model (ELM) prediction

The efficacy of Kriging spatial interpolation for filling temporal gaps in daily air temperature data: A case study in northeast China

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Research in Cold and Arid Regions 2016年第5期8卷 441-449页

作者： YanLin Zhang XiaoLi Chang Ji Liang DongLiang Luo ruixia he National-Local Joint Engineering Laboratory of Geo-Spatial Information Technology Hunan University of Science and Technology State Key Laboratory of Frozen Soils Engineering Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences

Quality-controlled and serially complete daily air temperature data are essential to evaluating and modelling the influences of climate change on the permafrost in cold regions. Due to malfunctions and location changes of observing stations, temporal gaps （i.e., missing data） are common in collected datasets. The objective of this study was to assess the efficacy of Kriging spatial interpolation for estimating missing data to fill the temporal gaps in daily air temperature data in northeast China. A cross-validation experiment was conducted. Daily air temperature series from 1960 to 2012 at each station were estimated by using the universal Kriging （UK） and Kriging with an external drift （KED）, as appropriate, as if all the ob-servations at a given station were completely missing. The temporal and spatial variation patterns of estimation uncertainties were also checked. Results showed that Kriging spatial interpolation was generally desirable for estimating missing data in daily air temperature, and in this study KED performed slightly better than UK. At most stations the correlation coefficients （R2） between the observed and estimated daily series were 〉0.98, and root mean square errors （RMSEs） of the estimated daily mean （Tmean）, maximum （Tmax）, and minimum （Tmin） of air temperature were 〈3 ℃. However, the estimation quality was strongly affected by seasonality and had spatial variation. In general, estimation uncertainties were small in summer and large in winter. On average, the RMSE in winter was approximately 1 ℃ higher than that in summer. In addition, estimation uncertainties in mountainous areas with complex terrain were significantly larger than those in plain areas.

关键词： daily air temperature gap filling Kriging spatial interpolation northeast China

Evolution and changes of permafrost on the Qinghai-Tibet Plateau during the Late Quaternary

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Research in Cold and Arid Regions 2017年第1期9卷 1-19页

作者： XiaoLi Chang HuiJun Jin ruixia he LanZhi Lu StuartA.Harris Hunan University of Science and Technology XiangtanHunan 411202China State Key Laboratory of Frozen Soils Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhouGansu 730000China Department of Geography University of Calgary2500 University DriveNW CalgaryAlbertaCanada T2N1N4

Due to the uplift of Qinghai-Tibet Plateau （QTP）, the cryosphere gradually developed on the higher mountain summits after the Neocene, becoming widespread during the Late Quaternary. During this time, permafrost on the QTP experienced repeated expansion and degradation. Based on the remains and cross-correlation with other proxy records such as those from glacial landforms, ice-core and paleogeography, the evolution and changes of permafrost and environmental changes on the QTP during the past 150,000 years were deduced and are presented in this *** least four obvious cycles of the extensive and intensive development, expansion and decay of permafrost occurred during the periods of 150-130, 80-50, 30-14 and after 10.8 ka B.P.. Ehiring the Holocene, fluctuating climatic environ-ments affected the permafrost on the QTP, and the peripheral mountains experienced six periods of discernible permafrost changes：（1） Stable development of permafrost in the early Holocene （10.8 to 8.5-7.0 ka B.P.）; （2） Intensive permafrost degradation during the Holocene Megathermal Period （HMP, from 8.5-7.0 to 4.0-3.0 ka B.P.）; （3） Permafrost expansion during the early Neoglacial period （ca. 4,000-3,000 to 1,000 a B.P.）; （4） Relative degradation during the Medieval Warm Period （MWP,from 1,000 to 500 a B.R）; （5） Expansion of permafrost during the Little Ice Age （LIA,from 500 to 10.a B.P.）; （6） Observed and predicted degradation of permafrost during the 20th and 21st century. Each period differed greatly in paleoclimate, paleoenvironment, and permafrost distribution, thickness, areal extent, and ground temperatures, as well as in the development of periglacial phenomena. Statistically, closer dating of the onset permafrost formation, more identi-fication of permafrost remains with richer proxy information about paleoenvironment, and more dating information enable higher resolution for paleo-permafrost reconstruction. Based on the scenarios of persistent climate warming of 2 2 -2 .6 °C in

关键词： Qinghai-Tibet Plateau (QTP) Pleistocene Holocene permafrost expansion and degradation periglacial remains paleo-reconstruction environmental impacts

Freeze-thaw processes of active-layer soils in the Nanweng'he River National Natural Reserve in the Da Xing'anling Mountains,northern Northeast China

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Research in Cold and Arid Regions 2018年第2期10卷 104-113页

作者： ruixia he HuiJun Jin XiaoLi Chang YongPing Wang LiZhong Wang State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhouGansu 730000China School of Civil Engineering Harbin Institute of TechnologyHarbinHeilongjiang 150090China Hunan University of Science and Technology XiangtanHunan 411201China School of Civil Engineering North University of NationalitiesYinchuanNingxia 750030China Nenjiangyuan Forest Ecosystem Research Station Institute of Agriculture and ForestryDa Xing'anling Forestry GroupJiagedaqiHeilongjiang 165000China

The active-layer soils overlying the permafrost are the most thermodynamically active zone of rock or soil and play important roles in the earth-atmosphere energy system. The processes of thawing and freezing and their associated complex hydrothermal coupling can significantly affect variation in mean annual temperatures and the formation of ground ice in permafrost regions. Using soil-temperature and-moisture data obtained from the active layer between September 2011 and October 2014 in the permafrost region of the Nanweng'he River in the Da Xing'anling Mountains, the freeze-thaw characteristics of the permafrost were studied. Based on analysis of ground-temperature variation and hydrothermal transport characteristics, the thawing and freezing processes of the active layer were divided into three stages:(1) autumn-winter freezing,(2) winter freeze-up, and(3) spring-summer thawing. Variations in the soil temperature and moisture were analyzed during each stage of the freeze-thaw process, and the effects of the soil moisture and ground vegetation on the freeze-thaw are discussed in this paper. The study's results show that thawing in the active layer was unidirectional, while the ground freezing was bidirectional(upward from the bottom of the active layer and downward from the ground surface).During the annual freeze-thaw cycle, the migration of soil moisture had different characteristics at different stages. In general, during a freezing-thawing cycle, the soil-water molecules migrate downward, i.e., soil moisture transports from the entire active layer to the upper limit of the permafrost. In the meantime, freeze-thaw in the active layer can be significantly affected by the soil-moisture content and vegetation.

关键词： Nanweng'he River National Natural Reserve active layer freeze-thawing processes moisture content vegetation effect

Evolution of permafrost in China during the last 20 ka

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Science China Earth Sciences 2019年第8期62卷 1207-1223页

作者： Huijun JIN Xiaoying JIN ruixia he Dongliang LUO Xiaoli CHANG Shaoling WANG Sergey S MARCheNKO Sizhong YANG Chaolu YI Shijie LI Stuart A HARRIS Northeast China Observational Station of Cold-regions Engineering and Environment State Key Laboratory of Frozen Soils EngineeringNorthwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou730000China School of Civil Engineering Harbin Institute of TechnologyHarbin150090China School of Resources and Environment University of Chinese Academy of ScienceBeijing100049China Hunan University of Science and Technology Xiangtan411201China Permafrost Laboratory Geophysical InstituteUniversity of Alaska FairbanksFairbanksAK99775USA GFZ German Research Centre for Geosciences TelegrafenbergPotsdam D-14473Germany Institute of Tibetan Plateau Research Chinese Academy of SciencesBeijing100010China Institute of Geochemistry Chinese Academy of SciencesGuiyang550081China Department of Geography University of CalgaryCalgaryAlberta T2N1N4Canada

The formation and evolution of permafrost in China during the last 20 ka were reconstructed on the basis of large amount of paleo-permafrost remains and paleo-periglacial evidence, as well as paleo-glacial landforms, paleo-flora and paleofauna records. The results indicate that, during the local Last Glacial Maximum(LLGM) or local Last Permafrost Maximum(LLPMax), the extent of permafrost of China reached 5.3×106-5.4×106 km2, or thrice that of today, but permafrost shrank to only0.80×106-0.85×106 km2, or 50% that of present, during the local Holocene Megathermal Period(LHMP), or the local Last Permafrost Minimum(LLPMin). On the basis of the dating of periglacial remains and their distributive features, the extent of permafrost in China was delineated for the two periods of LLGM(LLPMax) and LHMP(LLPMin), and the evolution of permafrost in China was divided into seven periods as follows:(1) LLGM in Late Pleistocene(ca. 20000 to 13000-10800 a BP)with extensive evidence for the presence of intensive ice-wedge expansion for outlining its LLPMax extent;(2) A period of dramatically changing climate during the early Holocene(10800 to 8500-7000 a BP) when permafrost remained relatively stable but with a general trend of shrinking areal extent;(3) The LHMP in the Mid-Holocene(8500-7000 to 4000-3000 a BP)when permafrost degraded intensively and extensively, and shrank to the LLPMin;(4) Neoglaciation during the late Holocene(4000-3000 to 1000 a BP, when permafrost again expanded;(5) Medieval Warming Period(MWP) in the late Holocene(1000-500 a BP) when permafrost was in a relative decline;(6) Little Ice Age(LIA) in the late Holocene(500-100 a BP), when permafrost relatively expanded, and;(7) Recent warming(during the 20 th century), when permafrost continuously degraded and still is degrading. The paleo-climate, geography and paleopermafrost extents and other features were reconstructed for each of these seven periods.

关键词： Permafrost evolution Cryogenic wedge structures Local Last Glacial Maximum(LLGM) Local Holocene Megathermal Period(LHMP) China

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医学生社交媒体能力现状的调查研究

卫生职业教育 2024年第21期42卷 91-94页

作者：庄月华陈艺茹贺瑞霞伍桂仪谢宝仪庞晓丽申滨艳韶关学院广东韶关512005

目的了解医学生社交媒体能力水平,并探讨其影响因素。方法采用方便抽样法,选取某高校临床医学、医学检验技术和护理学3个专业本科生152人为研究对象,开展问卷调查。结果医学生社交媒体能力量表总均分为(3.32±0.63)分,处于中等水平,其... 详细信息

目的了解医学生社交媒体能力水平,并探讨其影响因素。方法采用方便抽样法,选取某高校临床医学、医学检验技术和护理学3个专业本科生152人为研究对象,开展问卷调查。结果医学生社交媒体能力量表总均分为(3.32±0.63)分,处于中等水平,其中专业、对专业的兴趣程度以及是否开展过相关实践是医学生社交媒体能力的影响因素。结论医学生社交媒体能力不理想,在今后的医学教育中,应根据学生专业背景和兴趣特点,有针对性地开展社交媒体能力培养。

关键词：医学生社交媒体能力健康教育

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