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[Display omitted] • A comprehensive economic risk assessment framework for BTSSCP is constructed. • Combined risk probability and ecological loss to calculate landscape ecological risk. • Predicts the evolution of landscape ecological risk for multiple development scenarios. • Make recommendations for the BTSSCP Sustainable Development Programme. The comprehensive effect of multi-source factors has altered the landscape pattern and ecological processes within the Beijing-Tianjin Sandstorm Source Control Project (BTSSCP) area, resulting in a fragile environment. Scientific evaluation of the landscape ecological risk (LER) in the project area and identification of the drivers of landscape ecological risk are crucial for preventing and resolving ecological risks and protecting the ecosystem in northern China. This study aims to establish an ecological risk assessment framework, analyze the spatiotemporal changes in the LER in the BTSSCP area from 2000 to 2020, evaluate different factors in depth using the Geodetector model, and predict the LER in 2030 under multiple development scenarios using the patch-generating land use model. The results showed that (1) the dominant land use type in the BTSSCP area was grassland, accounting for more than 50 % of the total area, followed by cropland, unused land, and woodland. (2) The average LERI values in the BTSSCP area for 2000, 2010, and 2020 were 0.023, 0.022, and 0.021, respectively. This demonstrates that the LER in the study as a whole was low and steadily declined. (3) The LER in the project area was influenced by multiple factors. Overall, the evolution of the LER in the study area was primarily affected by natural factors, and the amount of interaction among the multiple factors increased over time. Locally, the normalized difference vegetation index and mean annual temperature were both important factors in this area. [ABSTRACT FROM AUTHOR]

In desert areas, the process of mobile sandy land changing to semi‐fixed sandy land and eventually to fixed sandy land after undergoing vegetation restoration is inevitable. The presence of shrub patches and herb patches is common in this restoration process. No relevant studies have reported the soil bacterial community characteristics of different vegetation‐type patches (shrub patches and herb patches) under different stages of restoration. Therefore, we utilized long‐established experimental plots to collect soil from 0–20 cm soil layer under shrub patches (dominated by Salix psammophila) and herb patches under different stages of restoration (i.e., mobile sand land, semi‐fixed sand land, and fixed sand land), by determining soil physicochemical properties, enzyme activities, and soil bacterial communities. Our results found that soil bacterial α‐diversity under different restoration stages showed higher shrub patches than herb patches. The dominant bacterial communities (phyla) in shrub patches and herb patches at different recovery stages were Actinobacteria, Proteobacteria, and Bacteroidota. When the mobile sandy land returned to fixed sandy land, the relative abundance of Actinobacteria and Bacteroidota gradually decreased under shrub patches and herb patches, while the relative abundance of Proteobacteria increased significantly. In addition, herb patches significantly increased the relative abundance of bacteria (genus) relative to shrub patches at different stages of recovery. Soil nutrients, soil fine particles, and soil enzyme activities were significantly higher under shrub patches than under herb patches when fixed sandy land due to differences in life form and architecture between shrub patches and herb patches. Based on this, soil bacterial community composition and diversity under shrub patches were driven by more soil properties during the restoration of sandy land. This study complements the dynamic recovery processes and driving mechanisms of soil bacterial community structure under different vegetation patches in sandy areas, especially in the context of global climate change. [ABSTRACT FROM AUTHOR]

Wind erosion is a severe environmental problem in arid, semi-arid region of the world, and it occurs frequently in northwest part of China and leads to soil degradation. Inner Mongolia is located in Northern China as a very important ecological barrier with various of landforms including desert, grassland and forest. In order to quantify the regional soil degradation degree and predict potential wind erosion risk, 5 typical sites of wind erosion, i.e. Jilantai Gebi, Ulan Buh desert, Mu Us sandy land, Wuchuan farmland and Xilamuren Grassland were chosen as experimental sites. Based on digital image technology, the pictures of these 5 sites were taken using Canon EF24-105 mm, and the grey scale information of the images was analyzed by Erdas-Image software; an area compensation equation was established to obtain the actual particle size, and then the residual amount of coarse surface was calculated. On the basis of wind erosion estimation model of Inner Mongolia Houshan Area, surface un-erodible particle (>0.84 mm) was chosen as key indicator combined with local strong wind days, and then an applicable soil erosion potential risk exponential equation was established and the soil potential wind erosion risk was evaluated. The results suggested that wind erosion was a physical process of erodible particle loss, as a result, serious degradation surface kept a high content of coarse grains. Jilantai Gebi and surface around shrub has experienced severe wind erosion, for there existed a large proportion of coarse particles, indicating that the area was in late period of the coarsening process with strong anti-erosion ability, and the average anti-erosion indices were 91.40% and 81.40% respectively. Soil particles of Ulan Buh Desert showed obvious spatial heterogeneous characteristics due to the effect of few shrub communities, and the soil anti-wind erosion ability was Artemisia xerophytica Krasch plot > Artemisia arenaria DC.plot > Nitraria tangutorum plot. In Mu Us Sandy land, aeolian material was the main component and the vegetation coverage was less than 5%; the area was dominated by barchan, and soil particle content showed intensive spatial heterogeneity with variation coefficient of 37%, which was mainly caused by different position of sand dunes. The anti-erosion index was only 13.40% indicating that wind erosion occurred easily in this site. In terms of typical farming land, surface fine material was maintained at a high level due to frequent plow activities, which led to a lower anti-erosion index of 29.40%; on the contrary, due to long-term wind erosion, much fine particle of abandoned farmland got lost, at last soil surface was covered by coarsening grains mostly, and the anti-wind erosion index was greater than that of farming land. Soil particle turned to show obvious spatial heterogeneity in deserted grassland, un-erodible particle decreased along with the distance far away from the tourist area, and the regional average anti-erosion index was 45.20%. Poor soil and strong wind were the main factors contributing to the sand dust in the tested areas. Based on the potential wind erosion risk equation, Jilantai Gebi was in the lowest potential wind erosion risk among the 5 sites, and it showed that soil surface reached a new stable balance. The potential wind erosion risk of shrub communities in Ulan Buh Desert was contrary to anti-wind erosion ability. However, based on the analysis effect, potential wind erosion risk was farmland > abandoned land > shift sand dune, which seemed to be a little bit abnormal. This was because farmland surface was looser than others, and there were different strong wind days among these areas. As a simple prediction equation, it was applicable in different sites of arid areas, especially in small scale predication, as was shown in the results. Farmland and grassland were in higher wind erosion risk and was becoming a new sand source, and human disturbance played an important role in this process. [ABSTRACT FROM AUTHOR]

As part of the ecological barrier and an essential element of food security, the agro-pastoral ecotone is vital in northern China. Since soil fertility in northern China is low due to frequent surface disturbances, it is necessary to improve the properties of the soil. This study aims to examine the impact of fungal residue return on soil properties based on six treatments (CK: 0 kg/40 m2; R3: 90 kg/40 m2; R5: 150 kg/40 m2; R7: 210 kg/40 m2; R9: 270 kg/40 m2; R11: 330 kg/40 m2;) of fungal residue return concentration experimental data from 0 to 30 cm soil depth. The results showed that the effect of fungal residue returning on soil habits was greater at 0–10 cm of the surface layer. The bulk density can be reduced to 25.83% of CK, and water content can be increased up to 26.26%. Adding fungal residue to the field led to a greater increase in soil parameters (SOM and AP), and this characteristic effect continued as the return concentration increased. The number of soil bacteria and actinomycetes remained stable, and the amount of fungi was at its lowest. Compared with CK, the number of bacteria, fungi, and actinomycetes increased by 1.94 times, 1.46 times, and 1.71 times, respectively. After the residue was returned to the field, AK had the strongest correlation with other factors (p < 0.01), and microorganism and enzyme activities were strongly correlated (p < 0.01). In conclusion, this study presents a new method of resource utilization of downstream wastes in the food industry while simultaneously providing natural, pollution-free improvements to the soil, which is very beneficial to increasing crop yield. [ABSTRACT FROM AUTHOR]

[Display omitted] • Natural degradation of the Salix psammophila sand barrier increased the microbial C: N: P stoichiometric ratios of desert soils. • Microbial C:N and N:P ratios were well regulated by homeostasis. • Microorganisms mitigated P limitation by altering the fungal community structure rather than bacteria. • Mass loss and fungal diversity played strong roles in shaping soil microbial stoichiometry ratios. The Salix psammophila sand barrier is widely used to control wind-sand disasters in desert areas. Importantly, the means through which the natural degradation of the sand-buried section of these sand barriers contributes to the community-level microbial elemental homeostasis of desert soils remains elusive. In this study, we conducted long-term field in situ sampling experiments over a nine-year period in a typical study area in the desert region of northwest China. Chloroform fumigation and high-throughput sequencing were used to determine soil microbial biomass and the diversity of fungi and bacteria. Combined with sand barrier decay characteristics, soil physicochemical factors, and extracellular enzyme activities, we explored the dynamic balance of soil microbial element ratios and key driving factors. The results show that natural degradation of S. psammophila sand barriers increased microbial biomass C and N contents in desert soil, with seven years being the most important turning point. The consistent increase in the soil microbial C:N:P stoichiometry ratios was primarily directly caused by an increase in the mass loss and changes in the fungal diversity. Microbial C:N and N:P ratios were well limited over time, suggesting homeostatic regulation of microorganisms, but the C:P ratio was not homogenized at the community level. The higher microbial C:P and N:P ratios indicated that microorganisms were limited by P after five years of sand barrier degradation. This was primarily related to a decrease in the soil alkaline phosphatase activity. However, microorganisms mitigated P limitation by altering the fungal community structure. These results constitute new evidence in our understanding of the relationships between S. psammophila sand barriers and soil element stoichiometry and the subsequent effects on microorganisms and community-level elemental homeostasis. This work advances the current understanding of artificial interventions in ecological restoration and desertification control. [ABSTRACT FROM AUTHOR]

• Sand-fixing measures improve the dispersion and heterogeneity of soil particles. • Soil multifractal is regulated by soil nutrients and vegetation factors. • Soil multifractal parameter is an important index of soil development in desert ecosystem. In the fragile desert ecosystems of the world, sand-fixing measures play an irreplaceable part in ecological restoration. However, it is unclear how the long-term establishment of sand-fixing measures affects soil particle distribution and soil nutrients for the desert – Yellow River coastal ecotone. Therefore, we selected sand-fixing measures that have been established for fifteen years: Pinus sylvestris (PS), Populus alba (PA), Elaeagnus angustifolia (EA), Hedysarum scoparium (HS), Salix psammophila (SC), Salix psammophila checkerboard barriers (SCSB), and mobile sandy land (LS). We analyzed soil physical properties, chemical properties, soil fractal dimension (D), and multi-fractal parameters in the top soil layer (0–20 cm). The results showed that the establishment of sand-fixing measures significantly increased the clay and silt, and decreased the sand (p < 0.05). Sand-fixing measures promote the heterogeneity of soil particle distribution and increase its dispersion. The soil nutrition content was significantly increased under different sand-fixing measures (p < 0.05), and soil organic carbon (SOC) and alkaline nitrogen (AN) changed significantly. The D value is between 2.18 and 2.39. The D value and multifractal parameters were driven by soil physicochemical properties and aboveground biomass (AGB). The regression model demonstrates a significant correlation between the D values and multi-fractal parameters (R2 = 0.58–0.77, p < 0.001). Therefore, we suggest that multifractal parameters can replace the D values as indicators of soil environmental changes in desertification. This study complements the information on the restoration of soils in the desert-Yellow River coastal ecotone by sand-fixing measures. In addition, we suggest that desert ecological management should be tailored to regional environmental differences to establish an integrated model of restoration of sand-fixing measures in the future. The results of this study scientifically provide a theoretical basis for the future reconstruction of ecologically fragile areas. [ABSTRACT FROM AUTHOR]