In sensitive ecosystems of the Arctic, even slight disruptions may produce serious damage. Therefore, the extent of contamination in such zones should be evaluated. A comparison was made between concentrations of metals in Sanionia uncinata in three areas of the European Arctic: (1) the vicinity of the Polish Polar Station in the SW part of Spitsbergen on Wedel Jarlsberg Land, (2) Longyearbyen (Spitsbergen) influenced by local sources of pollution and (3) Iceland relatively free from local pollution. The tested hypothesis was that S. uncinata from Iceland contains significantly lower concentrations of metals than the same moss from Spitsbergen. The maximum concentrations of metals in the examined moss from Longyearbyen reached values for Cr and Mn higher than those known as harmful for plants and for Ni and Zn values within the harmful ranges with no visible harmful effects. S. uncinata from Iceland contained significantly lower concentrations of Cd, Mn, Pb compared to this species from Spitsbergen. S. uncinata seems to be a useful indicator for metal fallout in the European Arctic. This study presents the effects of local sources of contamination on metal levels in S. uncinata from Longyearbyen, Wedel Jarlsberg Land and Iceland as well as verification of S. uncinata as a suitable bioindicator in this Arctic area. The benefit of the study is a to better understanding contamination problems of Arctic habitats.

Background and aims Vascular plants and moss biocrusts are known to coexist in drylands, wherein vascular plant cover is known to be a major influencing factor for biocrusts development. Vascular plants produce litter which may affect moss biocrusts when covering them. However, to which extent the cover of litter may affect the physiology, e.g., photosynthetic activity, of moss biocrusts remains poorly understood.MethodsWe studied the effect of the litter covering on biocrust-forming mosses on the northern Chinese Loess Plateau over four-month period. We used litter from shrubs of Artemisia ordosica and Caragana korshinskii with two levels of litter thickness, and monitored moss greenness, and several indicators of moss physiological activity.ResultsLitter covering reduced moss greenness, content of chlorophyll a and b, soluble sugar, and soluble protein, suggesting a reduced photosynthetic and metabolic activity of mosses under litter cover. On the other hand, mosses covered by litter showed higher contents of malondialdehyde, proline, and catalase activity compared to those mosses without any litter cover, suggesting that litter covering increased oxidative stress in mosses and triggered a protective response against oxidative damage. Moreover, we found litter thickness exerted a more significant impact on the physiological indices of mosses than litter type.ConclusionsOur results demonstrate the detrimental effects of litter covering on the physiological activity of biocrust-forming mosses. The findings provide a mechanistic understanding of the reductions in mosses in ecosystems with high shrub cover, highlighting the importance of litter in mediating the relationships between moss biocrusts and shrub patches.

Phytoremediation, the practice of removing heavy metals from contaminated sites using plants, has emerged as a cost-effective, environmentally friendly green technology to restore damaged ecosystems. Mosses, in particular, demonstrate high phytoremediation potential due to their ability to accumulate heavy metals such as lead, zinc, copper, chromium, cadmium, and iron from contaminated soil and water. This review systematically examines 37 research articles published from 2000 to 2022, focusing on the on the use of mosses for phytoremediation. Moss species, such as Funaria hygrometrica Hedw, Scopelophila cataractae (Mitten) Brotherus, Dicranum scoparium Hedw, Dicranum polysetum Sw. ex anon, Hypnum cupressiforme Hedw, Physcomitrium cyathicarpum Mitt, Barbula constricta Mitt, and Leptodictyum riparium (Hedw.) Warnst. have been identified as ideal candidates for phytoremediation efforts. Specific species of mosses, such as Dicranum species, are noted for their excellent bioaccumulation capabilities of elements like vanadium, manganese, and rubidium, serving as indicators of air pollution. Additionally, Hypnum cupressiforme has proven to be a reliable indicator of sulfur dioxide in natural and anthropogenic sources. This comprehensive review highlights the significant phytoremediation potential of mosses, emphasizing their role as valuable bioaccumulators and indicators of heavy metals and pollutants. The findings highlight the necessity of further research to enhance the application of mosses in environmental management and remediation strategies, ultimately contributing to the development of sustainable and effective solutions for pollution control.

Dryland degradation is a global problem, destabilizing ecosystems and disrupting coupled human-natural systems in arid regions. Degradation, caused by livestock grazing, wildfire, vehicles, construction, climate perturbances, and other surface disturbances, open space for invasive plants to establish while damaging soils, biological soil crusts (biocrusts), and vascular plant communities. Due to the scale of invasive plant infestations and the cost of mechanical control, invasive plants are commonly treated with herbicides, but little is known about the consequences of herbicides on biocrust. Biocrusts are communities of biota that aggregate the soil surface and provide ecosystem services, including mitigating soil erosion and fixing nitrogen, making biocrust a promising and emerging tool to counteract degradation. To test biocrust compatibility with standard herbicide treatments, we conducted a organisms (mosses and the lichens Placidium/Clavascidium and Enchylium). We found that response varied based on the herbicide mechanistic family, with the magnitude of response varying for biocrust organisms. Mosses treated with amino acid disrupters (glyphosate and imazapic) had 65-75% less health tissue area than controls after 3 months. Surprisingly, mosses treated with synthetic auxins (2,4-D and aminopyralid) had a similar or slightly greater healthy area. Blue dye and surfactants had no effect on any tested biocrust organism. This greenhouse study suggests that through careful selection of herbicides, biocrust restoration could be simultaneously used with herbicide treatments of invasive plants to improve soil health.

Salt stress is a significant abiotic stress that adversely affects pepper plant growth which can accelerate the development of plant pathogens and increase plant susceptibility to diseases. Verticillium dahliae, which causes pepper wilt disease, is an important biotic stress factor. Funneliformismosseae and biochar organic wastes help to take nutrients from the soil by establishing symbiotic connections with plant roots and, are effective in treating plant diseases, plant growth, and stress tolerance. This study aims to determine the effects of F. mosseae (Fm) and 2% biochar (Bc) against V. dahliae (Vd) on some plant physiological properties, plant nutrient uptake, soil pH, and EC value in pepper plants grown under salt stress (50mM, 100mM, 150mM). As a result of the study, the use of F. mosseae alone or in interaction with 2% biochar significantly increased some physiological parameters and some minerals (P, K, Mg, and Mn) contents of the plant. Moreover, pepper plants showed remarkable resistance to salt and stress factors caused by V. dahliae. In addition, the interaction between F. mosseae and biochar significantly lowered the soil EC value under conditions of severe salt stress. On the other hand, biochar was more effective than F.mosseae in terms of soil pH and Ca/Na ratio. The results showed that biochar and F. mosseae were beneficial in reducing biotic ( V. dahliae) and abiotic stress (salt stress) damage while enhancing plant growth and nutrient absorption. Therefore, this study yields excellent and novel results, particularly in the field of employing beneficial microorganisms for sustainable agriculture.

Svalbards permafrost is thawing as a direct consequence of climate change. In the Low Arctic, vegetation has been shown to slow down and reduce the active layer thaw, yet it is unknown whether this also applies to High Arctic regions like Svalbard where vegetation is smaller, sparser, and thus likely less able to insulate the soil. Therefore, it remains unknown which components of High Arctic vegetation impact active layer thaw and at which temporal scale this insulation could be effective. Such knowledge is necessary to predict and understand future changes in active layer in a changing Arctic. In this study we used frost tubes placed in study grids located in Svalbard with known vegetation composition, to monitor the progression of active layer thaw and analyze the relationship between vegetation composition, vegetation structure and snow conditions, and active layer thaw early in summer. We found that moss thickness, shrub and forb height, and vascular vegetation cover delayed soil thaw immediately after snow melt. These insulating effects attenuated as thaw progressed, until no effect on thaw depth was present after 8 weeks. High Arctic mosses are expected to decline due to climate change, which could lead to a loss in insulating capacity, potentially accelerating early summer active layer thaw. This may have important repercussions for a wide range of ecosystem functions such as plant phenology and decomposition processes. Temperatures are rising in the Arctic, causing increased thaw of the layer of soil located above the permanently frozen ground. In Low Arctic regions vegetation cools the soil, which reduces the thawing. So far, we do not know whether the small plants growing in the High Arctic may be able to slow or reduce thaw. We measured soil thaw throughout the summer in High Arctic Svalbard in locations where vegetation composition is known. We also measured thickness of the moss layer, height of plants and snow depth. We found that moss thickness was the strongest factor in insulating the soil. Also the cover of plants, height of shrubs and forbs, and height of grass-like plants slowed soil thaw in the early summer. The insulating effects became less over time and no effects were found 8 weeks after onset of thaw. As climate change is causing changes in the Arctic vegetation, mosses and small shrubs are expected to decrease. As we found these to be the most important factors in insulating the soil, a future decrease in mosses and small shrubs may cause accelerated soil thaw at the start of summer. High Arctic vegetation slows active layer thaw in early summer after snow melt Mosses show a stronger negative relation with thaw depth than vascular vegetation Factors influencing active layer thaw change over time in early summer

The intensity and frequency of forest fires are increasing in the cultural landscape of central Europe as the climate is becoming warmer and drier. This requires an understanding of natural regeneration processes in forests and the effects of traditional and new approaches to restoring fire-damaged forests; however, it warrants more research in Germany, where large-scale stand-replacing fire is a new phenomenon in recent times. Specifically, early successional plant pioneer communities, such as mosses, influence the regenerating forest system, by providing viable conditions and habitats for subsequent plant species. The present work focuses on the processes that take place in the moss communities undergoing management interventions of a gradient of intervention intensities after fire disturbance. In a plot-based field inventory, we investigated early successional moss communities three years after a forest fire in Brandenburg, Germany. The study area was subjected to various postfire interventions: high intensity site preparation and dense row planting, natural regeneration (no intervention), and a moderate site preparation in combination with low-density group planting approach. Utilizing Bray-Curtis-based nonmetric multidimensional scaling to assess similarities among postfire moss communities, a simplification of moss communities under high-intensity postfire intervention was observed. We found that the diversity and abundance of mosses decreased with the application of high-intensity postfire intervention but increased with the application of moderate postfire interventions. Furthermore, we found a higher share of light-demanding pioneer mosses in areas under high intensity postfire intervention. In areas under moderate or no postfire intervention, more shade-tolerant species were present. We conclude that moderate interventions with low-intensity site preparation and group planting resulted in reduced losses of moss species and coverage in the successional moss community.

针对无人飞行器合成孔径雷达(UAVSAR)差分干涉测量可用于形变监测的发展潜力，介绍了美国UAVSAR的系统设计、工作原理、数据产品等，概述了国内外UAVSAR系统的发展与应用现状、存在问题和发展趋势，重点讨论了UAVSAR在火山、断裂、冰川、冻土、滑坡、地面沉降等典型地表形变监测的应用。其高空间分辨率和较强的穿透性是对星载SAR数据极好的补充，彰显了UAVSAR系统极大的应用前景，为国内机载雷达系统的研究及其在地质灾害监测方面提供参考。

针对无人飞行器合成孔径雷达(UAVSAR)差分干涉测量可用于形变监测的发展潜力，介绍了美国UAVSAR的系统设计、工作原理、数据产品等，概述了国内外UAVSAR系统的发展与应用现状、存在问题和发展趋势，重点讨论了UAVSAR在火山、断裂、冰川、冻土、滑坡、地面沉降等典型地表形变监测的应用。其高空间分辨率和较强的穿透性是对星载SAR数据极好的补充，彰显了UAVSAR系统极大的应用前景，为国内机载雷达系统的研究及其在地质灾害监测方面提供参考。

Extensive, detailed information on the spatial distribution of active layer thickness (ALT) in northern Alaska and how it evolves over time could greatly aid efforts to assess the effects of climate change on the region and also help to quantify greenhouse gas emissions generated due to permafrost thaw. For this reason, we have been developing high-resolution maps of ALT throughout northern Alaska. The maps are produced by upscaling from high-resolution swaths of estimated ALT retrieved from airborne P-band synthetic aperture radar (SAR) images collected for three different years. The upscaling was accomplished by using hundreds of thousands of randomly selected samples from the SAR-derived swaths of ALT to train a machine learning regression algorithm supported by numerous spatial data layers. In order to validate the maps, thousands of randomly selected samples of SAR-derived ALT were excluded from the training in order to serve as validation pixels; error performance calculations relative to these samples yielded root-mean-square errors (RMSEs) of 7.5-9.1 cm, with bias errors of magnitude under 0.1 cm. The maps were also compared to ALT measurements collected at a number of in situ test sites; error performance relative to the site measurements yielded RMSEs of approximately 11-12 cm and bias of 2.7-6.5 cm. These data are being used to investigate regional patterns and underlying physical controls affecting permafrost degradation in the tundra biome.