Subarctic palsa mires are natural indicators of the status of permafrost in its sporadic distribution zone. Estimation of the rate of their thawing can become an auxiliary indicator to predict climate shifts. The formation, growth, and degradation of palsas are dynamic processes that depend on seasonal weather fluctuations and local environmental factors. Therefore, accurate forecasts of palsas conditions and related ecosystem shifts must be based on a broad set of attributes of palsas from different regions of the Northern Hemisphere. With this in mind, we studied two palsa mires sites on the Kola Peninsula, for which no thorough descriptions were previously available. The first site, Chavanga, is at the southern limit of the permafrost zone under unfavorable climatic conditions and is a collapsing relic. The second site, Ponoy, in contrast, is within the sporadic permafrost zone with relatively cold and dry conditions. Our dataset was created by combining several methods to produce detailed spatial models of permafrost for the studied palsa mires. We used 3D ground-penetrating radar (GPR) survey, UAV-based orthophoto maps, peat thermometry, time-domain reflectometry, and manual sampling. We developed two integrated geospatial models that describe the active layer, the configuration of the palsa frozen core, and its thermal state and identify the zones of the most intense thawing. These observations revealed a significant thermal effect of the groundwater flow and its critical role in the palsas segmentation and rapid collapse. We have investigated a regulating effect of micromorphological features of palsa mounds such as heights, slope, depressions, and mire mineral bed through groundwater drainage. As a result, two new scenarios for the palsa degradation process have been developed, emphasizing the influence of environmental factors on the permafrost condition.

研究和测试表明，土壤凝结成冻土时，其电阻率可增加5～1000倍。在冬季，土壤由浅入深逐步形成冻土高阻层，直到最大冻结深度；在春季反之，冻土高阻层由表入里的消散。在这个周期变化的过程中，冻土深度内的土壤电阻率产生剧烈变化，对变电站接地网的性能产生动态、显著的不利影响，提高了GPR和降低了接触电压允许值。当前，在变电站接地的工程设计中，对此鲜有相关的研究和应用。廊坊柳林220 kV变电站作为重点工程，采用分层土壤模型等效实际冻土条件，首次对接地网的性能进行了工程量化的评估和校验。测试结果表明，采用分层土壤模型等效的方式是可行的，冻土校验和评估涉及安全性评估，是必要的。

Characterizing permafrost is crucial for understanding the fate of arctic and subarctic archaeological archives under climate change. The loss of bio-physical integrity of archaeological sites in northern regions is still poorly documented, even though discontinuous permafrost is particularly vulnerable to global warming. In this study, we documented the spatial distribution of the permafrost-supported Inuit archaeological site Oakes Bay 1 on Dog Island (Labrador, Canada) while employing a novel approach in northern geoarchaeology based on non-invasive geophysical methods. ERT and GPR were successfully used to estimate active layer thickness and image permafrost spatial variability and characteristics. The results made it possible to reconstruct a conceptual model of the current geocryological context of the subsurface in relation to the site topography, hydrology, and geomorphology. The peripherical walls of Inuit semi-subterranean sod houses were found to contain ice-rich permafrost, whereas their central depressions were identified as sources of vertical permafrost degradation. The geophysical investigations were used to classify the permafrost at Oakes Bay 1 as climate-driven, ecosystem-protected permafrost that cannot regenerate under current climate conditions. This work highlights how the permafrost at Oakes Bay 1 is currently affected by multi-point thermal degradation by both conduction and advection, which makes it highly sensitive to climate warming.

长江源地区的冰川变化揭示了青藏高原气候变化趋势。冰下地形探测作为冰川发育和运动过程研究的基础，对长江地区水土保持和淡水资源储量研究具有指导意义。长江科学院在长达10 a的江源科考基础上，分别于2022年、2023年采用探地雷达(GPR)技术对长江正源沱沱河发源地格拉丹东主峰的冰川厚度进行精准探测，并对查旦湿地冻土厚度上限进行了探测研究。结合多种冰川和冻土地质模型的GPR波场模拟结果，提高了GPR技术在长江源地区冰川和冻土探测的有效性和精准度。探测结果表明，格拉丹东主峰冰川厚度和查旦湿地冻土厚度上限均有不同程度降低，冰川厚度和冻土厚度上限观测是一个常年积累的结果，后续仍需持续进行观测，积累更多数据，分析变化趋势，以估算探测区域内冰储量，研究气候变化对冰川的影响效果。

Microorganisms that are halophilic and halotolerant have gradually developed unique structures, physiologies, and genomes to survive. They are essential for ecological restoration and pollution control. This review emphasizes the critical role of halophilic and halotolerant microorganisms in plant stress tolerance, the ability to degrade a wide range of organic pollutants, the potential for cultural heritage conservation and restoration, and the impact on the spread of resistance genes. Halophilic and halotolerant microorganisms tolerate salt by controlling osmotic pressure in the cytoplasm via one of two major mechanisms: compatible solute accumulation or inorganic ion accumulation. Besides, the ability of halophilic and halotolerant microorganisms to survive high salt concentrations is also related to enzymatic proteins with fascinating physicochemical and structural properties. The advantage of halophilic enzymes is their ability to maintain enzyme stability and activity under high salt concentrations and organic reagents. The review of halophilic and halotolerant microorganisms is critically valuable for the reclamation of saline lands and pollutant degradation in highly saline environments.

Permafrost distribution is of great significance for the study of climate, ecology, hydrology, and infrastructure construction in high-cold mountain regions with complex topography. Therefore, updated high-resolution permafrost distribution mapping is necessary and highly demanded in related fields. This case study conducted in a small catchment in the northeast of the Qinghai Tibet Plateau proposes a new method of using ground-penetrating radar (GPR) to detect the stratigraphic structure, interpret the characteristics of frozen ground, and extract the boundaries of permafrost patches in mountain areas. Thus, an empirical-statistical model of mountain frozen ground zonation, along with aspect (ASP) adjustment, is established based on the results of the GPR data interpretation. The spatial mapping of the frozen ground based on this model is compared with a field survey dataset and two existing permafrost distribution maps, and their consistencies are all higher than 80. In addition, the new map provides more details on the distribution of frozen ground. In this case, the influence of ASP on the distribution of permafrost in mountain areas is revealed: the adjustment of ASP on the lower limit of continuous and discontinuous permafrost is 180-200 m, the difference in the annual mean ground temperature between sunny and shady slopes is up to 1.4-1.6 degrees C, and the altitude-related temperature variation and uneven distribution of solar radiation in different ASPs comprehensively affect the zonation of mountain frozen ground. This work supplements the traditional theory of mountain permafrost zonation, the results of which are of value to relevant scientific studies and instructive to engineering construction in this region.

Investigations into the susceptibility of permafrost landscapes response to thermokarst can be performed using various approaches, depending on the scale of investigation. In many cases, point-based field measurements are extrapolated to larger scales and vice versa. The integration of scales often requires some form of ground control in addition to remote sensing surveys, which are at times exclusively conducted. As upscaling from discrete field measurements can provide spatial coverage and landscape-scale significance, downscaling from remote sensing can offer insight into processes and serve as calibration or verification. Here we present a multiple-scale evaluation of an area initially interpreted as a relict active layer detachment slide (before 1950) on Melville Island in the High Arctic, where differential interferometric synthetic aperture radar (DInSAR) showed subsidence between 2013 and 2015. Ground-based, cryostratigraphy measurements were combined with ground-penetrating radar (GPR) to investigate permafrost ice-content. The results indicate greater subsidence within the relict active layer detachment as detected by DInSAR. GPR surveys and permafrost coring indicated the presence of an ice-rich or massive ice layer near the base of the active layer in this area. In addition, cryostratigraphic evidences of thaw unconformity and of massive ice depth helped validate the interpretations of the geomorphology in the active layer detachment. This combination of methods indicated a localized and inherited landform-subsidence association, which brought further insight into the interpretation of DInSAR subsidence data. The framework presented in this study demonstrates the importance of site-specific investigations of thermokarst signal in order to understand the processes behind the remote sensing results. (C) 2020 Elsevier B.V. All rights reserved.

The subsurface structure of permafrost is of high significance to forecast landscape dynamics and the engineering stability of infrastructure under human impacts and climate warming, which is a modern challenge for Arctic communities. Application of the non-destructive method of geo-penetrating radar (GPR) survey is a promising way to study it. The study program, which could be used for planning and monitoring of measures of adaptation of Arctic communities to environmental changes is provided in this paper. The main principle was to use etalons of coupled radargrams and archive geological data to interpret changes in the permafrost structure from a grid of 5-10 m deep GPR transects. Here, we show the application of GPR to reconstruct and predict hazards of activation of cryogenic processes from the spatial variability in the structure of permafrost. The cumulative effects of the village and climate change on permafrost were manifested in changes in the active layer thickness from 0.5-1.0 m to up to 3.5 m. Despite that the permafrost degradation has declined due to the improved maintenance of infrastructure and the effects of ground filling application, the hazards of heaving and thermokarst remain for the built-up area in Lorino.

季冻区路基在冻融作用下常常发生冻胀、融沉等病害,其中路基土的温、湿度水平是致灾的重要因素。针对现有监测手段单一,路基温、湿度全时空监测困难等问题,利用远程无线传输技术,设计了一种基于GPRS(通用分组无线服务)通信技术的季冻土路基温、湿度双参数监测系统,可以实时监测路基温、湿度变化。系统采用土壤专用的温、湿度传感器作为采集终端;以STC89C52单片机作为主控制器,通过编辑AT指令控制GPRS连通网络和数据收发,实现温、湿度数据远程传输和存储。经实际验证该系统采集精度高、稳定可靠、操作方便,可实现对季冻土路基内部温、湿度的实时无损监测。

对分离自青海昆仑山口冻土荒漠区植被根围的7株可在4及10℃低温条件下正常生长的低温适生菌进行鉴定分析,并检测其拮抗病原菌活性及催芽促生特性。综合理化测定、BOX-PCR及ERIC-PCR指纹图谱分析、16S rDNA及基因gyrB序列鉴定结果,其中6株菌株为简单芽孢杆菌Bacillus simplex,1株菌株为B.malacitensis。平板对峙试验表明,7株菌株对油菜菌核病原菌Sclerotinia sclerotiorum及水稻白叶枯病原菌Xanthomonas oryzae pv.oryzae具有显著拮抗效果。以菌株KLD2(B.simplex)及KLD5(B.malacitensis)发酵菌液处理玉米种子及拟南芥幼苗,结果表明菌株发酵液可明显促进种子萌发及幼苗生长,其鲜重、根长、须根数等表征均有显著增加。几株低温适生PGPR(plant growth promoting rhizobacteria)芽孢杆菌具备抗菌、催芽及促生特性,具有农业应用潜力。