Southern boundary areas of high-latitude permafrost regions may represent the future permafrost temperature regimes; therefore, understanding the carbon stocks and their stability in these systems can shed light on the permafrost carbon cycle under a warming climate. In this study, we sampled soils at three sites representing three differing land covers (forest swamp, dry forest, and shrub swamp) located in the southern boundary area of a high-latitude permafrost region and investigated their carbon fractions and the relationships of these fractions with soil physicochemical parameters in the active and permafrost layers. The results show that the proportion of active carbon is higher in permafrost than in the active layer under forest swamp and dry forest, implying that carbon pools in the permafrost are more decomposable. However, in shrub swamp, the active carbon components in the permafrost layer are lower than in the active layer. Soil pH and water content are the most significant factors associated with soil organic carbon concentration both in the active layers and in the permafrost layers. Our results suggest that, although soil organic carbon concentrations largely decrease with depth, the proportion of the forest swamp, dry forest labile carbon is higher in the permafrost layer than in the active layer and that the vertical distribution of labile carbon proportions is related to land covers.

Wind erosion can cause desertification and sandstorms in arid and semiarid areas. However, quantitative studies of the dynamic changes in wind erosion over long time periods are relatively rare, and this knowledge gap hinders our un-derstanding of desertification under the conditions of a changing climate. Here, we selected the Mongolian Plateau as the study area. Using the revised wind erosion equation (RWEQ) model, we assessed the spatial and temporal dy-namics of wind erosion on the Mongolian Plateau from 1982 to 2018. Our results showed that the wind erosion inten-sity on the Mongolian Plateau increased from northeast to southwest. The annual mean wind erosion modulus was 46.5 t center dot ha-1 in 1982-2008, with a significant decline at a rate of -5.1 t center dot ha-1 center dot 10 yr-1. The intensity of wind erosion was the strongest in spring, followed by autumn and summer, and was weakest in winter. During 1982-2018, wind erosion showed a significant decreasing trend in all seasons except winter. The wind erosion contribution of spring to the total annual wind erosion significantly increased, while that of summer significantly decreased. These results can help decision-makers identify high-risk areas of soil erosion on the Mongolian Plateau and take effective measures to adapt to climate change.