Understanding soil organic carbon (SOC) distribution and its environmental controls in permafrost regions is essential for achieving carbon neutrality and mitigating climate change. This study examines the spatial pattern of SOC and its drivers in the Headwater Area of the Yellow River (HAYR), northeastern Qinghai-Xizang Plateau (QXP), a region highly susceptible to permafrost degradation. Field investigations at topsoils of 86 sites over three summers (2021-2023) provided data on SOC, vegetation structure, and soil properties. Moreover, the spatial distribution of key permafrost parameters was simulated: temperature at the top of permafrost (TTOP), active layer thickness (ALT), and maximum seasonal freezing depth (MSFD) using the TTOP model and Stefan Equation. Results reveal a distinct latitudinal SOC gradient (high south, low north), primarily mediated by vegetation structure, soil properties, and permafrost parameters. Vegetation coverage and above-ground biomass showed positive correlation with SOC, while soil bulk density (SBD) exhibited a negative correlation. Climate warming trends resulted in increased ALT and TTOP. Random Forest analysis identified SBD as the most important predictor of SOC variability, which explains 38.20% of the variance, followed by ALT and vegetation coverage. These findings likely enhance the understanding of carbon storage controls in vulnerable alpine permafrost ecosystems and provide insights to mitigate carbon release under climate change.

The alpine ecosystems of the Qinghai-Tibet Plateau (QTP) provide multiple ecosystem services. In recent decades, these ecosystem services have been profoundly affected by climate change, human activity, and frozen ground degradation. However, related research remains lacking to date in the QTP. To address this gap, the upper reaches of the Shule River, a typical cryospheric-dominated basin in the QTP, was selected. We simultaneously assessed the spatial-temporal patterns and driving factors of ecosystem services, including habitat quality (HQ), net primary productivity (NPP), water conservation (WC), carbon storage (CS), water yield (WY), green space recreation (GSR), and total ecosystem service (TES), by employing the InVEST, CASA, and Noah-MP land surface models in combination with remote sensing and field survey data. Our results showed that: (1) HQ, NPP, WC, CS, WY, and GSR all increased significantly from 2001 to 2020 at rates of 0.004 a(-1), 1.920 g Cm(-2)a(-1), 0.709 mma(-1), 0.237 Mg & sdot;ha(-1)a(-1), 0.212 x 10(8) m(3)a(-1), and 0.038 x 10(9) km(2)a(-1) (P < 0.05), respectively; (2) warm and humid climates, combined with shrinking of barren, contributed to the increases in HQ, NPP, WC, CS, WY, and GSR; (3) frozen ground degradation had promoting effects on HQ, NPP, CS, GSR, and TES, while inhibiting effects were observed on WY and WC (P < 0.05); (4) synergies among ecosystem services were prominent over the past 20 years; (5) the total ecosystem service value increased significantly at a rate of 1.18 x 10(9) CNYa(-1) from 2001 to 2020 (P < 0.05), primarily due to the increase in the provisioning service value.

This study highlights the results of a palaeoecological analysis conducted on five permafrost peatlands in the northern tundra subzone along the Barents Sea coast in the European Arctic zone. The depth of the peat cores that were sampled was approximately 2 m. The analysis combined data on the main physical and chemical soil properties, radiocarbon dating, botanical composition, and mass fraction of polycyclic aromatic hydrocarbons (PAHs). The concentrations of 16 PAHs in peat organic layers ranged from 140 to 254 ng/g, with an average of 182 ng/g. The peatlands studied were dominated by PAHs with a low molecular weight: naphthalene, phenanthrene, fluoranthene, pyrene, chrysene. The vertical distribution patterns of PAHs along the peat profile in the active layer and permafrost were determined. PAHs migrating down the active layer profile encounter the permafrost barrier and accumulate at the boundary between active layer and permafrost layer. The deep permafrost layers accumulate large amounts of PAHs and PAH derivatives, which are products of lignin conversion during the decomposition of grassy and woody vegetation during the Holocene climate optima. The total toxic equivalency concentration (TEQ) was calculated. Peatlands from the Barents Sea coast have low toxicity for carcinogenic PAHs throughout the profile. TEQ ranged from a minimum of 0.1 ng/g to a maximum of 13.5 ng/g in all peatlands investigated. For further potential use in Arctic/sub-Arctic environmental studies, PAH indicator ratios were estimated. In all investigated sections and peatland horizons, the most characteristic ratios indicate the petrogenic (natural) origin of PAHs.

Temperature and precipitation are the primary factors restricting litter decomposition in desert ecosystems. The desert ecosystems in Central Asia are ecologically fragile regions, and the climate shows a trend of warm and wet due to the regional climate change. However, the influencing mechanisms of warming and winter snow changes on litter decomposition are still poorly understood in desert ecosystems. Furthermore, the litter decomposition rate cannot be directly compared due to the large variations in litter quality across different ecosystems. Here, we simulated warming and altered winter snow changes in the field, continuously monitored litter decomposition rates of standard litter bags (i.e., red tea and green tea) and a dominant plant species (i.e., Erodium oxyrrhynchum) during a snow-cover and non-snow-cover period over five months. We found that warming and increased snow cover increased the litter decomposition rate of red tea, green tea, and Erodium oxyrhinchum, and had significant synergistic effects on litter decomposition. The effects of warming and winter snow changes on litter decomposition were more pronounced in April, when the hydrothermal conditions were the best. The decomposition rates of all three litter types belowground were higher than those on the soil surface, highlighting the important roles of soil microbes in accelerating litter decomposition. Furthermore, we found that warming and winter snow changes altered litter decomposition by influencing soil enzyme activities related to soil carbon cycling during the snow-cover period, while influencing soil enzyme activities related to soil phosphorus cycling during the non-snow-cover period. And, notably, decreased snow cover promoted soil enzyme activities during the snow-cover period. More interestingly, our results indicated that the decomposition rate (k) was the lowest, but the stability factor (S) was the highest in the Gurbant & uuml;ngg & uuml;t Desert based on the cross-ecosystem comparison using the Tea Bag Index method. Overall, our results highlighted the critical roles of warming and winter snow changes on litter decomposition. In future research, the consideration of relationships between litter decomposition and soil carbon sequestration will advance our understanding of soil carbon cycling under climate change in desert ecosystems.

Biological soil crusts (BSCs; biocrusts) are well developed in drylands, which are crucial to the stability and resilience of dryland ecosystems. In the southeastern Gurbantunggut Desert, a typical sandy desert in the middle part of central Asia, engineering development has an increasing negative impact on ecosystems. Fortunately, ecological restoration measures are being implemented, but the exact effect on soil quality is still unclear. In artificial sand-fixing sites on reshaped dunes along the west-east desert road, a total of 80 quadrats (1 m x 1 m) of reed checkerboards after the implementation of sand-fixing measures for 10 years were investigated to determine the BSC development status and soil properties. The algal and lichen crusts accounted for 48.75 % and 26.25 % of the total quadrat number, respectively, indicating an obvious recovery effect of BSC (only 25 % for bare sand). The developmental level of BSC gradually increased from the top to the bottom of the dunes (Li 0 -> Li 6),which was consistent with the distribution pattern of BSCs on natural dunes. Compared with bare sand, the soil organic carbon (13.85 % and 23.07 % increases), total nitrogen (12.55 % and 23.95 % increases), total potassium (9.30 % and 8.24 % increases), and available nitrogen (23.97 % and 61.41 % increases) contents of algal and lichen crusts were significantly increased, and lichen crusts had markedly higher increase effect than algal crusts. The BSC development markedly reduced soil pH (0.49 % and 0.50 % decreased) and increased electrical conductivity(11.99 % and 10.68 % increases), resulting in improved soil microenvironment. Soil properties showed significant linear relationships with BSC development level, and an optimal fitting (R2 = 0.770 or 0.780) was detected for the soil fertility index. Based on the soil property matrix, the bare sands, algal, and lichen crusts were markedly separated along the first axis in the PCA biplot, which once again confirmed the significant positive effect of BSC recovery on soil fertility improvement. Consequently, in the early stage of sand-fixation (e.g., < = 10 years) by reed checkerboards on the damaged desert surface, BSC recovery can well promote and predict soil fertility in this area. The results provide a reliable theoretical basis for the restoration technology and scientific management of degraded sandy desert ecosystems.

Hurricane Otto caused sequential changes in tropical soil microbiota over 5 years.Acidobacteria were critical early decomposers of deposited canopy debris for 3 years.Complex C degrading fungi were critical later decomposers of debris starting at 4 years.A suite of C, N and microbial indicators should prove valuable for forest managers.Hurricanes cause significant damage to tropical forests; however, little is known of their effects on decomposition and decomposer communities. This study demonstrated that canopy debris deposited during Hurricane Otto stimulated sequential changes in soil carbon (C) and nitrogen (N) components, and decomposer microbial communities over 5 years. The initial response phase occurred within 2 years post-hurricane and appeared associated with decomposition of the labile canopy debris, suggested by: increased DNA sequences (MPS) of the Acidobacterial community (as common decomposers of labile plant material), decreases in total organic C (TOC), increased biomass C, respiration, and NH4+, conversion of organic C in biomass, and decreased MPS of complex organic C decomposing (CCDec) Fungal community. After 3 years post-hurricane, the later response phase appeared associated with decomposition of the more stable components of the canopy debris, suggested by: increased MPS of the Fungal CCDec community, TOC, stabilized Respiration, decreased Biomass C, the return to pre-hurricane levels of the conversion of organic C to biomass, and decreased MPS of Acidobacterial community. These changes in the microbial community compositions resulted in progressive decomposition of the hurricane-deposited canopy material within 5 years, resulting several potential indicators of different stages of decomposition and soil recovery post-disturbance.

As a typical cold region, Northeast China is characterized by its unique climate, hydrological conditions, and land systems, which collectively shape the diversity and complexity of regional ecosystem services (ESs). This review systematically examines research on ESs in Northeast China from 1997 to 2025, with particular emphasis on recent advances in service classification and spatiotemporal patterns, trade-offs and synergies among ESs, the identification of driving mechanisms, regulatory pathways, and policy effectiveness. The findings reveal obvious spatial heterogeneity and distinct stage-wise changing patterns in ESs across the region, with particularly pronounced trade-offs between food production and regulating services. The primary driving factors are concentrated in natural and human activities dimensions, whereas region-specific variables and policy-related drivers remain underexplored. Current research predominantly employs methods such as correlation analysis and geographically weighted regression; however, the capacity to uncover causal mechanisms and nonlinear interactions remains limited. Future research should strengthen the simulation of ecological processes in cold regions, improve the balance between ES supply and demand, improve policy scenario assessments, and develop dynamic feedback mechanisms. Compared with previous studies focusing on single services or regions, this review provides a multidimensional perspective by synthesizing multiple ES categories, integrating spatiotemporal comparative analysis, and incorporating modeling strategies specific to cold-region dynamics. These efforts will help shift ES research beyond static description toward more systematic regulation and management, providing both theoretical support and practical guidance for sustainable development and ecological governance in Northeast China.

The European rabbit (Oryctolagus cuniculus) is a keystone species in Mediterranean ecosystems but also considered a pest in some agricultural areas. Despite its threatened status due to diseases and habitat loss, rabbit populations thrive in motorway verges, causing conflicts with human activities. In this study we examine the factors affecting rabbit warren abundance in motorway verges in central Spain, with implications for conservation and management. The research aimed to assess the importance of infrastructure (e.g. motorway slopes) and landscape (e.g. land use, soil depth) factors on rabbit warren abundance along 1631 km of motorway verges and to develop an index for broader-scale abundance and risk assessment. Using generalized linear mixed models, the study revealed that both infrastructure (slope) and landscape factors (soil depth, vegetation structure and land cover gradients) significantly influenced warren abundance. Rabbit warrens were more abundant in agricultural landscapes with deep soils and in intermediate slope ranges. The findings suggest that rabbit abundance in motorway verges is driven by a combination of factors involving both infrastructure features but also land use in surrounding areas. The derived model predictions were able to correctly discriminate between crop damaged and non-damaged areas, highlighting its potential as a tool for conflict mitigation and conservation planning. The study underscores the need to integrate landscape and infrastructure features into wildlife management strategies to address human-wildlife conflicts effectively. Future work should include direct population monitoring and explore broader ecological impacts, such as predator dynamics and wildlife-vehicle collisions.

The pollution of metal ions triggers great risks of damaging biodiversity and biodiversity-driven ecosystem multifunctioning, whether microbial functional gene can mirror ecosystem multifunctionality in nonferrous metal mining areas remains largely unknown. Macrogenome sequencing and statistical tools are used to decipher linkage between functional genes and ecosystem multifunctioning. Soil samples were collected from subdams in a copper tailings area at various stages of restoration. The results indicated that the diversity and composition of soil bacterial communities were more sensitive than those of the fungal and archaeal communities during the restoration process. The mean method revealed that nutrient, heavy metal, and soil carbon, nitrogen, and phosphorus multifunctionality decreased with increasing bacterial community richness, whereas highly significant positive correlations were detected between the species richness of the bacterial, fungal, and archaeal communities and the multifunctionality of the carbon, nitrogen, and phosphorus functional genes and of functional genes for metal resistance in the microbial communities. SEM revealed that soil SWC and pH were ecological factors that directly influenced abiotic factor-related EMF; microbial diversity was a major biotic factor influencing the functional gene multifunctionality of the microbiota; and different abiotic and biotic factors associated with EMF had differential effects on whole ecosystem multifunctionality. These findings will

With Arctic amplification, hydrological conditions in Arctic permafrost regions are expected to change substantially, which can have a strong impact on carbon budgets. To date, detailed mechanisms remain highly uncertain due to the lack of continuous observational data. Considering the large carbon storage in these regions, understanding these processes becomes crucial for estimating the future trajectory of global climate change. This study presents findings from 8 years of continuous eddy-covariance measurements of carbon dioxide (CO2) and methane (CH4) fluxes over a wet tussock tundra ecosystem near Chersky in Northeast Siberia, comparing data between a site affected by a long-term drainage disturbance and an undisturbed control site. We observed a significant increasing trend in roughness lengths at both sites, indicating denser and/or taller vegetation; however, the increase at the drained site was more pronounced, highlighting the dominant impact of drainage on vegetation structure. These trends in aboveground biomass contributed to differences in gross primary production (GPP) between the two sites increasing over the years, continuously reducing the negative effect of the drainage disturbance on the sink strength for CO2. In addition, carbon turnover rates at the drained site were enhanced, with ecosystem respiration and GPP consistently higher compared to the control site. Because of the artificially lower water table depth (WTD), CH(4 )emissions at the drained site were almost halved. Furthermore, drainage altered the ecosystem's response to environmental controls. Compared to the control site, the drained site became slightly more sensitive to the global radiation (R-g), resulting in higher CO(2 )uptake under the same levels of R-g. Meanwhile, CH(4 )emissions at the drained site showed a higher correlation with deep soil temperatures. Overall, our findings from this WTD manipulation experiment show that changing hydrological conditions will significantly impact the Arctic ecosystem characteristics, carbon budgets, and ecosystem's response to environmental changes.