Measurements of surface-atmosphere carbon dioxide (CO2) and methane (CH4) fluxes have been relatively sparse across the Arctic tundra and boreal biomes, causing significant uncertainties in carbon budget estimates from the region. While the availability of Arctic-boreal carbon flux data has increased substantially over the past decade, the data have remained spread across different repositories, scientific articles, and unpublished sources, making it difficult to leverage. Here we present a new dataset of monthly Arctic-boreal carbon fluxes (ABCFlux v2) across terrestrial (wetlands and uplands) and freshwater (lakes and rivers) ecosystems compiled from previous syntheses including the Arctic-boreal CO2 flux database (ABCFlux v1), the Boreal-Arctic Wetland and Lake Methane Dataset (BAWLD-CH4), and the Global River Methane Database (GRiMeDB). In addition, we consider data from general-purpose (e.g., Zenodo) and flux network repositories, literature, and site principal investigators. The dataset includes surface-atmosphere CO2 fluxes of gross primary production (GPP), ecosystem respiration (Reco), and net ecosystem exchange (NEE), alongside CH4 fluxes. For aquatic ecosystems, we split CH4 fluxes into diffusive and ebullitive flux pathways, and included potential emissions from transient storage in the water column (“storage fluxes”), alongside CO2 and CH4 concentrations dissolved in the surface water. Fluxes are measured through a variety of methods including chamber and eddy covariance techniques alongside bubble traps, ice-surveys, and concentration-based turbulence-driven modelling in aquatic ecosystems. The monthly flux data are reported together with supporting methodological and environmental metadata. The resulting ABCFlux v2 has 23 847 flux site-months, 8182 concentration site-months, and 199 seasonal observations from 1024 sites, and includes 56 139 reported fluxes (i.e. sum of GPP, Reco, NEE, and CH4 fluxes) from the years 1984 to 2024. The majority of monthly observations occurred after 1999. Wetlands had the highest number of site-month observations (8758), followed by boreal forest (6981), lotic ecosystems (6275), lentic ecosystems (3799) and upland tundra (3308). Measurements of CO2 dominated the dataset across most ecosystem types (25 222) except for lentic ecosystems, where CH4 flux site-months (3098) were more frequent than CO2 flux site-months (2915). Overall, ABCFlux v2 includes 160 % more site-months for terrestrial CO2 flux data compared to ABCFlux v1. Integrating and updating BAWLD-CH4 flux data from growing season averages to monthly fluxes resulted in 5671 site-months of chamber CH4 data compared to 762 site-years. This collaborative initiative, involving contributions from over 260 researchers, provides a comprehensive overview of the current state of the Arctic-boreal carbon flux network and its data, and serves as an important step in reducing uncertainties in Arctic-boreal carbon budgets and in enhancing our understanding of climate feedbacks. The data can be accessed at ORNL DAAC at https://doi.org/10.3334/ORNLDAAC/2448 (Virkkala et al., 2026).

The Arctic–Boreal Zone is rapidly warming, impacting its large soil carbon stocks. Here we use a new compilation of terrestrial ecosystem CO2 fluxes, geospatial datasets and random forest models to show that although the Arctic–Boreal Zone was overall an increasing terrestrial CO2 sink from 2001 to 2020 (mean ± standard deviation in net ecosystem exchange, −548 ± 140 Tg C yr−1; trend, −14 Tg C yr−1; P < 0.001), more than 30

Greenhouse gas (GHG) fluxes from forests, including carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), are regulated by complex interactions of abiotic and biotic factors. A better understanding of these interactions involving GHGs can help manage forests and enhance their sequestration potential. This review examines how soil properties (moisture, temperature, and pH) and tree species-specific traits (litter quality, carbon storage, and microbial regulation) interactively control GHG dynamics in temperate forest soils, moving beyond a single-factor perspective. This literature review confirms that temperate forest soils are CH4 sinks and sources of CO2 and N2O; however, flux direction and magnitude differ across spatial and temporal scales. CH4 fluxes show high spatial variability and are sensitive to biogeochemical conditions. While soil temperature and moisture are well studied, their combined effects with site-specific variables such as substrate availability, soil texture, and canopy structure remain underexplored. Tree litter plays a dual role: chemically influencing microbial physiological/functional traits through priming, thereby affecting CO2 and N2O, and physically limiting CH4 diffusion. These mechanisms collectively determine whether soils act as GHG sources or sinks, and future research should account for how litter priming may override their carbon sink function while integrating site-specific factors to improve GHG predictions and forest management.

Carbon dioxide fluxes were measured in the tundra ecosystem in order to evaluate the potential future sensitivity of the carbon cycle to climate change using chamber methods during summer in the Antarctic and high Arctic. The study sites are located on tundra in Baton Peninsula of King George Island, Antarctic Peninsula (62°13’ 28.87"S, 58°47’18.37"W) and high-arctic near Cambridge Bay, Nunavut, Canada (69°7'47.7"N, 105°3'35.3"W). The site of Baton Peninsula is mainly covered with various lichens and mosses and the site of Cambridge Bay is mainly covered with dwarf-shrubs, graminoids, mosses and lichens. CO2 flux was examined to understand change of the carbon cycle over the tundra ecosystems with various conditions for vegetation and soil. The emission CO2 flux and net CO2 exchange showed distinguished differences on type of vegetation and surface soil organic content. The variability of carbon flux depends on soil temperature and soil water content. Net CO2 exchange, soil respiration, and gross primary production were measured or calculated to investigate the influence of the ecosystem in the tundra carbon cycle in the Polar region. This study was supported by a National Research Foundation of Korea grant from the Korean government (MSIP) (NRF-2021M1A5A1065679 and NRF-2021R1I1A1A01053870) and PE 24130.

The Arctic-Boreal Zone (ABZ) is rapidly warming, impacting its large soil carbon stocks. We use a new compilation of terrestrial ecosystem CO2 fluxes, geospatial datasets and random forest models to show that although the ABZ was an increasing terrestrial CO2 sink from 2001 to 2020 (mean ± standard deviation in net ecosystem exchange: -548 ± 140 Tg C yr-1; trend: -14 Tg C yr-1, p<0.001), more than 30% of the region was a net CO2 source. Tundra regions may have already started to function on average as CO2 sources, demonstrating a critical shift in carbon dynamics. After factoring in fire emissions, the increasing ABZ sink was no longer statistically significant (budget: -319 ± 140 Tg C yr-1; trend: -9 Tg C yr-1), with the permafrost region becoming CO2 neutral (budget: -24 ± 123 Tg C yr-1; trend: -3 Tg C yr-1), underscoring the importance of fire in this region.### Competing Interest StatementThe authors have declared no competing interest.

This study analyzed the sensitivities of carbon cycle to surface air temperature using the CO _2 flux data collected from June to September for six years (2014–2019) over a moist tundra site in Council, Alaska. The tundra ecosystem was a strong sink of carbon in June and July, a weak sink in August with rapidly decreasing photosynthesis, and a carbon source in September. The ecosystem respiration (Re) and gross primary production (GPP) were obtained from the net ecosystem exchange (NEE) of eddy-covariance system. Both the Re and GPP increased with temperature, enhancing carbon emission and uptake during observation period. Notably, Re showed higher sensitivity to temperature than GPP did. This result means that as global warming continues, the increase in carbon release is greater than the increase in carbon uptake. In other words, the tundra ecosystem is expected to become a weaker carbon sink in June and July and a stronger source of carbon in September. Possible mechanism of different temperature sensitivities of Re and GPP as well as temporal variations of temperature sensitivities are suggested. Present results highlight the importance of understanding the temperature sensitivities of Re and GPP in various tundra ecosystems to accurately understand changes in the carbon cycle in the Arctic region.

Tundra and boreal ecosystems encompass the northern circumpolar permafrost region and are experiencing rapid environmental change with important implications for the global carbon (C) budget. We analysed multi-decadal time series containing 302 annual estimates of carbon dioxide (CO2) flux across 70 permafrost and non-permafrost ecosystems, and 672 estimates of summer CO2 flux across 181 ecosystems. We find an increase in the annual CO2 sink across non-permafrost ecosystems but not permafrost ecosystems, despite similar increases in summer uptake. Thus, recent non-growing-season CO2 losses have substantially impacted the CO2 balance of permafrost ecosystems. Furthermore, analysis of interannual variability reveals warmer summers amplify the C cycle (increase productivity and respiration) at putatively nitrogen-limited sites and at sites less reliant on summer precipitation for water use. Our findings suggest that water and nutrient availability will be important predictors of the C-cycle response of these ecosystems to future warming. The future of carbon dynamics in the northern high latitudes is uncertain yet represents an important potential feedback under climate change. This study uses a comprehensive observational dataset to show an increasing carbon sink in non-permafrost systems; in permafrost systems uptake was offset by loss.

A Gram-stain-negative, aerobic, reddish-coloured, rod-shaped and non-motile strain PAMC 29467T, was isolated from freshwater of the pond in Cambridge Bay, Canada. Strain PAMC 29467T was closely related to Hymenobacter yonginensis (98.1 % 16S rRNA gene similarity). Genomic relatedness analyses showed that strain PAMC 29467T is distinguishable from H. yonginensis based on average nucleotide identity (91.3 %) and digital DNA-DNA hybridization values (39.3 %). The major fatty acids (>10 %) of strain PAMC 29467T were summed feature 3 (C16 : 1  ω7c and/or C16 : 1  ω6c), C15 : 0 iso, C16 : 1  ω5c and summed feature 4 (C17 : 1 iso l and/or anteiso B). The major respiratory quinone was menaquinone-7. The genomic DNA G+C content was 61.5 mol%. Strain PAMC 29467T was separated from the type species in the genus Hymenobacter by its distinct phylogenetic position and some physiological characteristics. As a result, a novel species is proposed, with the name Hymenobacter canadensis sp. nov. (type strain, PAMC 29467T=KCTC 92787T=JCM 35843T).

&lt;p&gt;In this study, CO&lt;sub&gt;2&lt;/sub&gt;&amp;#160;and CH&lt;sub&gt;4&lt;/sub&gt; fluxes were measured in the tundra ecosystem in order to evaluate the potential future sensitivity of the carbon cycle to climate change using chamber systems and eddy covariance methods during summer in 2019 and 2022 in Canada. The study site is located on dry tundra with ponds in high-arctic near Cambridge Bay, Nunavut, Canada (69&amp;#176;7&#039;47.7&quot;N, 105&amp;#176;3&#039;35.3&quot;W). The vegetation cover around the site is mainly covered with dwarf-shrubs, graminoids, and lichens. CO&lt;sub&gt;2&lt;/sub&gt; and CH&lt;sub&gt;4&lt;/sub&gt; fluxes were examined to understand the mechanism of the carbon cycle over the tundra ecosystems with the pond. From chamber methods, the variability of net CO&lt;sub&gt;2&lt;/sub&gt; exchange was more sensitive to grass of wet condition than vegetation of dry condition and the variability and magnitude of CH&lt;sub&gt;4&lt;/sub&gt; emission near the pond was larger than that of dry condition. The emission CO&lt;sub&gt;2&lt;/sub&gt; and CH&lt;sub&gt;4&lt;/sub&gt; fluxes were examined positive relationship at almost bare soil of wet condition and negative relationship at various vegetation at dry condition. Net ecosystem exchange, ecosystem respiration, and gross primary production were measured or calculated using the both methods to investigate the influence of the ecosystem with ponds in the tundra carbon cycle. This study was supported by a National Research Foundation of Korea grant from the Korean government (MSIP) (NRF-2021M1A5A1065679 and NRF-2021R1I1A1A01053870).&amp;#160;&amp;#160;&lt;/p&gt;

Past efforts to synthesize and quantify the magnitude and change in carbon dioxide (CO2) fluxes in terrestrial ecosystems across the rapidly warming Arctic–boreal zone (ABZ) have provided valuable information but were limited in their geographical and temporal coverage. Furthermore, these efforts have been based on data aggregated over varying time periods, often with only minimal site ancillary data, thus limiting their potential to be used in large-scale carbon budget assessments. To bridge these gaps, we developed a standardized monthly database of Arctic–boreal CO2 fluxes (ABCflux) that aggregates in situ measurements of terrestrial net ecosystem CO2 exchange and its derived partitioned component fluxes: gross primary productivity and ecosystem respiration. The data span from 1989 to 2020 with over 70 supporting variables that describe key site conditions (e.g., vegetation and disturbance type), micrometeorological and environmental measurements (e.g., air and soil temperatures), and flux measurement techniques. Here, we describe these variables, the spatial and temporal distribution of observations, the main strengths and limitations of the database, and the potential research opportunities it enables. In total, ABCflux includes 244 sites and 6309 monthly observations; 136 sites and 2217 monthly observations represent tundra, and 108 sites and 4092 observations represent the boreal biome. The database includes fluxes estimated with chamber (19 % of the monthly observations), snow diffusion (3 %) and eddy covariance (78 %) techniques. The largest number of observations were collected during the climatological summer (June–August; 32 %), and fewer observations were available for autumn (September–October; 25 %), winter (December–February; 18 %), and spring (March–May; 25 %). ABCflux can be used in a wide array of empirical, remote sensing and modeling studies to improve understanding of the regional and temporal variability in CO2 fluxes and to better estimate the terrestrial ABZ CO2 budget. ABCflux is openly and freely available online (Virkkala et al., 2021b, https://doi.org/10.3334/ORNLDAAC/1934).

Recent rapid air temperature increases across the northern-latitude tundra have prolonged permafrost thawing and snow melting periods, resulting in increased soil temperature (Ts) and volumetric soil water content (SWC). Under prolonged soil warming at 8°C, Alaskan tundra soils were incubated in a microcosm system and examined for the SWC differential influence on the microbial decomposition activity of large molecular weight (MW) humic substances (HS). When one microcosm soil (AKC1-1) was incubated at a constant SWC of 41% for 90 days (T = 90) and then SWC was gradually decreased from 41% to 29% for another T = 90, the initial HS was partly depolymerized. In contrast, in AKC1-2 incubated at a gradually decreasing SWC from the initial 32% to 10% for T = 90 and then increasing to 27% for another T = 90, HS depolymerization was undetected. Overall, the microbial communities in AKC1-1 could maintain metabolic activity at sufficient and constant SWC during the initial T = 90 incubation. In contrast, AKC1-2 microbes may have been damaged by drought stress during the drying SWC regimen, possibly resulting in the loss of HS decomposition activity, which did not recover even after re-wetting to an optimal SWC range (20–40%). After T = 90, the CO2 production in both treatments was attributed to the increased decomposition of small-MW organic compounds (including aerobic HS-degradative products) within an optimal SWC range. We expect this study to provide new insights into the early effects of warming- and topography-induced SWC variations on the microbial contribution to CO2 emissions via HS decomposition in northern-latitude tundra soil.

The active layer thickness (ALT) is a key parameter for permafrost studies. Changes in the ALT are affected mainly by air and ground temperatures, physical and thermal properties of the surface and subsurface materials, soil moisture, vegetation, and the duration and thickness of snow cover. Ground penetrating radar (GPR) and electrical resistivity tomography (ERT) were employed across a snow fence during the thawing season to delineate and monitor the active layer of permafrost in Cambridge Bay, Nunavut, Canada. The variation of the ALT is well captured by the high-resolution time-lapse radargram. At the position of the fence, the active layer thickens over the thawing period from 0.5 m depth at the beginning to 1.0 m depth at the end. The active layer is thicker in the pre-fence area (C zone) than in the post-fence area (H zone). As the air temperature increases with time, the difference in thickness between the two zones decreases, eventually becoming almost equal. Changes in the ALT are represented in the ERT by low resistivities (< 200 Ωm), which decrease gradually with time. This occurs most significantly in the H zone due to the rapidly increasing temperature in the absence of snow cover. The electrical resistivity structure of the active layer is well correlated with the vegetation activity, as measured by the normalized difference vegetation index, air/ground temperatures, soil moisture, snow cover, and snow accumulation controlled by the fence. Geophysical data interpretation and correlation schemes with vegetation and meteorological data explored in this paper can be applied to monitor the active layer, which is expected to thin during the freezing season.

The regional variability in tundra and boreal carbon dioxide (CO 2 ) fluxes can be high, complicating efforts to quantify sink‐source patterns across the entire region. Statistical models are increasingly used to predict (i.e., upscale) CO 2 fluxes across large spatial domains, but the reliability of different modeling techniques, each with different specifications and assumptions, has not been assessed in detail. Here, we compile eddy covariance and chamber measurements of annual and growing season CO 2 fluxes of gross primary productivity (GPP), ecosystem respiration (ER), and net ecosystem exchange (NEE) during 1990–2015 from 148 terrestrial high‐latitude (i.e., tundra and boreal) sites to analyze the spatial patterns and drivers of CO 2 fluxes and test the accuracy and uncertainty of different statistical models. CO 2 fluxes were upscaled at relatively high spatial resolution (1 km 2 ) across the high‐latitude region using five commonly used statistical models and their ensemble, that is, the median of all five models, using climatic, vegetation, and soil predictors. We found the performance of machine learning and ensemble predictions to outperform traditional regression methods. We also found the predictive performance of NEE‐focused models to be low, relative to models predicting GPP and ER. Our data compilation and ensemble predictions showed that CO 2 sink strength was larger in the boreal biome (observed and predicted average annual NEE −46 and −29 g C m −2 yr −1 , respectively) compared to tundra (average annual NEE +10 and −2 g C m −2 yr −1 ). This pattern was associated with large spatial variability, reflecting local heterogeneity in soil organic carbon stocks, climate, and vegetation productivity. The terrestrial ecosystem CO 2 budget, estimated using the annual NEE ensemble prediction, suggests the high‐latitude region was on average an annual CO 2 sink during 1990–2015, although uncertainty remains high.

Recent increases in air temperature across the Antarctic Peninsula may prolong the thawing period and directly affect the soil temperature (Ts) and volumetric soil water content (SWC) in maritime tundra. Under an 8°C soil warming scenario, two customized microcosm systems with maritime Antarctic soils were incubated to investigate the differential influence of SWC on the bacterial community and degradation activity of humic substances (HS), the largest constituent of soil organic carbon and a key component of the terrestrial ecosystem. When the microcosm soil (KS1-4Feb) was incubated for 90 days (T = 90) at a constant SWC of ~32%, the initial HS content (167.0 mg/g of dried soil) decreased to 156.0 mg (approximately 6.6% loss, p < 0.05). However, when another microcosm soil (KS1-4Apr) was incubated with SWCs that gradually decreased from 37% to 9% for T = 90, HS degradation was undetected. The low HS degradative activity persisted, even after the SWC was restored to 30% with water supply for an additional T = 30. Overall bacterial community structure remained relatively stable at a constant SWC setting (KS1-4Feb). In contrast, we saw marked shifts in the bacterial community structure with the changing SWC regimen (KS1-4Apr), suggesting that the soil bacterial communities are vulnerable to drying and re-wetting conditions. These microcosm experiments provide new information regarding the effects of constant SWC and higher Ts on bacterial communities for HS degradation in maritime Antarctic tundra soil.

The morphology of Keronopsis helluo Penard, 1922, type species of Keronopsis, and Paraholosticha pannonica Gellért and Tamás, 1959, two little-known members of the Keronopsidae Jankowski, 1979, was described using standard methods. In addition, we sequenced the SSU rRNA of both species. Keronopsis helluo was isolated from a mossy soil from Robert Island (Antarctica) while P. pannonica was found in terrestrial moss from Alaska. Our data correspond very well with the original descriptions. The frontal ciliature of K. helluo is identical with that of Paraholosticha spp., indicating that some Keronopsis species (K. tasmaniensis, K. dieckmanni) are misclassified in the keronopsids. The type species has distinctly more transverse cirri (8–13) than K. wetzeli (1–3), type species of Parakeronopsis, which is thus perhaps a valid genus or subgenus. The phylogenetic analyses confirm the position of the keronopsids outside the Dorsomarginalia. The species sequenced so far (K. helluo, Paraholosticha muscicola, P. pannonica) emerge from a soft polytomy, which also comprises Bistichella-like species and a large cluster composed of amphisiellids, trachelostylids, and gonostomatids, that is, the method failed to resolve the relationships within the keronopsids. The Keronopsidae and the two species studied are characterized based on previous studies and our data.

The CO2 efflux from representative tundra ecosystems in the high Arctic should be monitored in order to evaluate the potential future sensitivity of the carbon cycle to climate change. However, studies on the soil CO2 efflux from them are still limited, especially deglaciated area due to the Arctic warming. The ecosystem in Ny-Alesund, Svalbard, Norway (similar to 79 degrees N) has gradually undergone substantial alterations due to deglaciation induced by climate change, where biological soil crusts (BSCs, mainly consisting of cyanobacteria, algae, lichen, and bryophytes, etc. on the soil surface) are widely formed in the glacier foreland and further developed especially in the later stages of primary succession. In this study, soil CO2 efflux from partly or totally covered with black-colored BSCs (BSCs-B) was measured from 2007 to 2009 using portable dynamic chamber system. The objectives of this study were (i) to quantify the CO2 efflux from the soil, (ii) to examine the controlling factors which affect the temporal and spatial variation of soil CO2 efflux, (iii) to examine the contribution of BSCs-B to soil CO2 efflux, and (iv) to estimate the relationship between soil CO2 efflux and microbial activity to evaluate its role on the surface carbon budget at deglaciated area. It was found that the emission of soil CO2 from BSCs-B was consistent through the long-term in situ measurement in the high arctic tundra. Soil CO2 efflux ranged from 0.3 to 0.7 mu mol m(-2) s(-1) with means of 0.56 (+/- 0.07) mu mol m(-2) s(-1) in 2007, 0.54 (+/- 0.13) mu mol m(-2) s(-1) in 2008, and 0.51 (+/- 0.09) mu mol m(-2) s(-1) in 2009. The soil temperature (Ts) explained 50-70% of the temporal variation of the soil CO2 efflux when temperature ranged from 6 to 12 degrees C, whereas Ts is not controlling factor for spatial variation of soil CO2 efflux considering the low coefficient of variation (CV). In the meanwhile, soil water content (SWC) was not a main controlling factor for temporal variation of soil CO2 efflux. Even though CV of SWC was not low, spatial variation of SWC could not explain that of soil CO2 efflux. The soil CO2 efflux was spatially affected by BSCs-B coverage, amount of pebble, and the nearby vegetation distribution. All enzyme activities exhibited significantly higher values in BSCs-B than in mineral soil of BSCs (p<0.01). The activities of enzymes in BSCs-B generally exhibited positive correlations with the soil CO2 efflux except for humic substances (R-2=0.52). It can be concluded that the magnitude of the soil CO2 efflux from BSCs-B is comparable to those from moss and vascular plants in the surface carbon budget. (C) 2015 Elsevier B.V. All rights reserved.

Humic substances (HS), primarily humic acids (HA) and fulvic acids (FA), are the largest constituent of soil organic matter. In microcosm systems with subarctic HS-rich tundra soil (site AK 1-75; approximately 5.6 °C during the thawing period) from Council, Alaska, the HA content significantly decreased to 48% after a 99-day incubation at 5 °C as part of a biologically mediated process. Accordingly, levels of FA, a putative byproduct of HA degradation, consistently increased to 172% during an identical incubation process. Culture-independent microbial community analysis showed that during the microcosm experiments, the relative abundance of phyla Proteobacteria (bacteria) and Euryarchaeota (archaea) largely increased, indicating their involvement in HS degradation. When the indigenous bacteria in AK 1-75 were enriched in an artificial mineral medium spiked with HA, the changes in relative abundance were most conspicuous in Proteobacteria (from 60.2 to 79.0%), specifically Betaproteobacteria-related bacteria. One hundred twenty-two HA-degrading bacterial strains, primarily from the genera Paenibacillus (phylum Firmicutes) and Pseudomonas (class Gammaproteobacteria), were cultivated from AK 1-75 and nearby sites. Through culture-dependent analysis with these bacterial isolates, we observed increasing HS-degradation rates in parallel with rising temperatures in a range of 0 °C to 20 °C, with the most notable increase occurring at 8 °C compared to 6 °C. Our results indicate that, although microbial-mediated HS degradation occurs at temperature as low as 5 °C in tundra ecosystems, increasing soil temperature caused by global climate change could enhance HS degradation rates. Extending the thawing period could also increase degradation activity, thereby directly affecting nearby microbial communities and rhizosphere environments.

To estimate the spatial variation of soil CO2 flux in a permafrost region, major environmental parameters were measured and analyzed using the proposed ubiquitous sensor network-based remote monitoring system (U-RMS). The use of techniques for power-efficient operation and network scalability that enable long-term use of a wireless sensor network (WSN) that can be deployed reliably and widely is described. The temporal and spatial variations in air temperature (Ta) and relative humidity (RH) near the surface at 16 locations and soil temperature (Ts) and soil water content (SWC) at 10 locations were measured to monitor the active permafrost layer in Alaska from September 2012 to January 2013 and from July to September 2013. The temporal variations in environmental parameters in the soil and near the surface depended on the thawing and freezing of the snow cover in the permafrost regions. The spatial patterns of Ts in the three periods were not similar because of the heterogeneous distribution of snow coverage and depth in winter. On the other hand, the spatial patterns of Ts and SWC had a negative relationship during summer. The spatial variations in Ts and SWC showed a high coefficient of variation (CV) that ranged from 20% to 40%, while the CV of Ta and RH was within 5% except in winter due to the spatially heterogeneous snow cover. The relationship between CO2 efflux and Ts or SWC in 2012, which had a high CV, was examined to estimate the soil CO2 efflux in 2013. The Ts explained ~60% (soil CO2 efflux=0.066×exp0.1443×Ts, R2 0.59) of the variation in soil CO2 efflux in a temperature range of 3 to 8°C. Therefore, the soil CO2 efflux in 2013 was estimated in the range of 0.08mgm−2s−1 to 0.47mgm−2s−1, and average CV was 25%. Using the camera sensor, the growth of vegetation and the operating appearance of the remote WSN were also monitored. In the long term, measurement of temporal and spatial variations in environmental parameters, based on U-RMS, is expected to contribute to the understanding of the carbon and water cycles in permafrost.