Wind and sand disaster prevention is a critical challenge for global environmental sustainability, with mechanical wind fences being key engineering measures. Current fences, including solid and permeable types, often struggle to balance environmental impact, windbreak efficiency, and stability. Solid fences provide effective sand control but have limited windbreak efficiency, while permeable fences improve airflow but require deep burial and are prone to erosion on uneven terrain. This study proposes a novel composite wind fence with a polylactic acid (PLA) sandbag base and a fiber mesh top, combining stability and permeability. We assessed windbreak performance using computational fluid dynamics simulations and verified results through wind tunnel experiments. Results show that the novel composite wind fence enhances windbreak efficiency and stability by optimizing airflow distribution, with the PLA sandbag base suppressing high–speed airflow and mesh fence weakening of leeward side vortices. Under wind speeds of 10 m/s, 18 m/s, and 28 m/s, the effective protection distance of the novel composite wind fence improved by 22.33% to 36.51%, 10.96% to 34.22%, and 0.94% to 28.98%, respectively, compared to single PLA and mesh wind fence. The optimal row spacing for the novel wind fences in three rows is 12 h when the incoming wind speed is 10 m/s, while the recommended spacings are 8 h and 6 h for wind speeds of 18 m/s and 28 m/s, respectively, ensuring continuous and effective protection. These findings present a novel wind fence technology with improved wind resistance, a more stable structure, and prolonged protective effects, offering an effective solution for environmental conservation initiatives aimed at preventing wind and sand disasters while promoting the sustainability of ecosystems.

Ecological restoration plays a crucial role in promoting soil organic carbon (SOC) accumulation after opencast coal mining. However, the mechanisms by which restoration measures mediate the formation, recovery, and sequestration of SOC in arid mining areas remain unclear. Here, we investigated plant- and microbial-derived carbon dynamics over an 8-year restoration period under different ecological restoration engineering measures, focusing on mineral-associated organic carbon (MAOC) and particulate organic carbon (POC) fractions. The SOC content increased with restoration duration, with the eco-bar measure showing the highest in situ carbon sequestration, though still lower than that in natural vegetation areas. The three restoration measures (eco-bar, hedge-row, and skeleton slope protection measure) significantly enhanced MAOC (averaging 5.00, 3.77, and 4.39 g kg-1 respectively) and POC (averaging 2.22, 1.87, and 2.23 g kg-1 respectively) concentrations, while increasing the proportion of MAOC and reducing that of POC. Specifically, mine restoration elevated plant-derived inputs, directly influencing POC through lignin phenols and microbial community shifts. In contrast, MAOC accumulation was primarily driven by microbial necromass-mineral interactions. These findings highlight the divergent pathways through which ecological restoration regulates SOC fractions. Overall, our study demonstrates that mine ecological restoration engineering measures contribute significantly to SOC accumulation and highlights their potential in arid mine restoration strategies for carbon sequestration and global climate change mitigation.

Soil organic carbon (SOC) has a critical influence on soil productivity and degradation. Meanwhile, ecological restoration is essential to prevent carbon (C) losses and reverse land degradation. In this study, 1374 sets of experimental data from 63 peer-reviewed publications were synthesized to quantitatively elucidate the effects of different restoration measures on soil properties and SOC fractions. The results showed that ecological restoration significantly increased SOC, particulate organic carbon (POC), and mineral-associated organic carbon (MAOC) by 37.48 %, 45.73 %, and 36.42 %, respectively. Interventional restoration measured the sequestered carbon in POC at a rate of 50.7 %, which was 17.1 % higher than that achieved through natural restoration. In the tropics, the effect of ecological restoration on MAOC was not significant. In addition, soil texture, soil depth, and restoration duration were important factors regulating the global SOC response to ecological restoration. In summary, the use of ecological restoration to achieve C recovery represents a site-specific application of both proactive and natural strategies. The meta-analysis advances our understanding of how SOC pools respond to various restoration measures and enhances the prediction of restoration outcomes under climate change scenarios.

In arid mining areas in China, several environmental issues, such as significant soil water and fertilizer seepage, high evaporation, and haphazard stacking of mining strips, make reforestation challenging. In this study, a novel pattern for enhancing water-retention in reconstructed soil using scientific ratios of mining strips is proposed. Experiments involved the utilization of two mining strips: crushed weathered mudstone (CWM) and crushed weathered sandstone (CWS). Four particle diameters (<0.25, 0.25-0.5, 0.5-2, and 2-5 mm) were employed to create three types of reconstructed soil (gravelly sandy soil, coarse-grained sandy soil, and medium-grained sandy soil). Afterwards, soil water-retention and related properties, as along with their relationships, were analyzed using multiple regression analysis, correlation analysis, and cluster analysis. The results reveal that proportions and particle sizes significantly (P < 0.05) influenced the physical and water-retention properties of reconstructed soils. Multiple regression analysis demonstrates a strong association between soil water-retention and particle size. Correlation analysis indicates that CWM has a more pronounced impact on the properties of reconstructed soil compared to CWS, especially within particle size ranges of 2-5 mm and 0.5-2 mm. Furthermore, the influencing factors on the reconstructed soil differed across the three stages of evaporation. It is recommended to maintain CWM content within 50%-70% to effectively inhibit evaporation and prevent water leakage. Among all, coarse-grained sandy soil stands out as a suitable option due to its excellent water-retention capacity. The findings can be valuable in the design and application of soil reconstruction and in alleviating water and soil loss in arid areas.

It is of great practical significance for regional sustainable development and ecological construction to quantitatively analyze the impact of construction land expansion on terrestrial ecosystem carbon storage and to explore the optimization scheme of simulating construction land expansion to improve future ecosystem carbon storage. Based on the land use and cover change (LUCC) and other geospatial data of the Beijing-Tianjin-Hebei Urban Agglomeration from 2000 to 2020, this study utilized the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model and the patch-generating land-use simulation (PLUS) model to assess and analyze the changes in ecosystem carbon stocks and spatial patterns regionally. In this study, we performed linear regression analysis to investigate the relationship between urban land expansion and changes in ecosystem carbon stocks for varying urban land proportion levels during two distinct time intervals, 2000-2010 and 2010-2020, which was conducted at a spatial resolution of 2 km. Three distinct urban land expansion scenarios were subjected to simulation to forecast the prospective land use pattern by 2030. Subsequently, we quantified the ramifications of these scenarios on ecosystem carbon stocks during the period from 2020 to 2030. The results were as follows:① In the Beijing-Tianjin-Hebei Urban Agglomeration, the ecosystem carbon stocks exhibited notable variations over the study period, with values of 2 088.02, 2 106.78, and 2 121.25 Tg recorded for the years 2000, 2010, and 2020, respectively, resulting in a cumulative carbon sequestration of 33.23 Tg C during the study duration. It is noteworthy that forest carbon storage emerged as the dominant contributor, with an increase from 1 010.17 Tg in 2000 to 1 136.53 Tg in 2020. Throughout the study period, the spatial distribution of carbon stocks displayed relative stability. Regions characterized by lower carbon content were concentrated in the vicinity of the Bohai Rim region and in proximity to cities such as Beijing, Tianjin, and Shijiazhuang, as well as rural settlements. In contrast, grid units with moderate and high carbon stocks were predominantly situated in the western Taihang Mountain and the northern Yanshan Mountain. Additionally, there was a tendency of increasing carbon stocks in the Taihang Mountain and Yanshan Mountain region, whereas those surrounding major urban centers such as Beijing, Tianjin, Shijiazhuang, and Tangshan experienced a notable decline in carbon stocks. Such reductions were most pronounced in regions undergoing urban land expansion during the study period. ② In grid units with an urban land proportion exceeding 10% at each level, a strong correlation was observed between urban land expansion and changes in carbon stocks during both the 2000-2010 and 2010-2020 periods. The changes in urban land proportion adequately explained the variations in carbon stocks. However, the explanatory power of urban land on carbon stocks decreased during the 2010-2020 period, indicating that other factors played a more substantial role in influencing carbon stocks during this time. The regression coefficients for both periods exhibited a fluctuating upward trend. In comparison to that during the 2000-2010 period, the impact of urban land expansion on carbon stocks was relatively smaller during 2010-2020, indicating a weakening influence. ③ In light of three distinct development scenarios, namely natural development (Scenario Ⅰ), a 15% reduction in the rate of urban land expansion (Scenario Ⅱ), and a 30% reduction in the rate of urban land expansion (Scenario Ⅲ), the projected ecosystem carbon stocks for the Beijing-Tianjin-Hebei Urban Agglomeration in the year 2030 were estimated to be 2 129.12, 2 133.55, and 2 139.10 Tg, respectively. These projections indicated an increase of 7.88, 12.30, and 17.85 Tg in comparison to the current carbon stocks. All scenarios demonstrated that the terrestrial ecosystem would play a role of carbon sink, particularly with the greatest carbon sink observed in the scenario with a 30% reduction in urban land expansion. The fit performance between urban land expansion and carbon stock changes during the 2020-2030 period was significantly better than that during the 2000-2010 and 2010-2020 periods, and the regression coefficients showed a fluctuating increase with an increase in urban land proportion. Across grid units with different urban land proportion levels, the regression coefficients exhibited the order of Scenario Ⅰ &lt; Scenario Ⅱ &lt; Scenario Ⅲ. In pursuit of the carbon peaking and carbon neutrality goals, the Beijing-Tianjin-Hebei Urban Agglomeration should prioritize scenarios with reduced rates of urban land expansion, especially in regions with higher urban land proportions.

Long-term occupation of coal gangue dumping sites (CGDS) may destroy ecological environment of nearby area. However, how the CGDS affects the distribution pattern of soil seed banks and vegetation in the nearby area is not clear. In this study, we investigated soil seed bank and vegetation at different distances from the second CGDS of Yangchangwan in Ningdong mining area, Lingwu, Ningxia. The results showed that soil seed bank was mainly distributed in 0-10 cm layer and decreased with increasing soil depth. Species richness of soil seed bank and vegetation first increased and then tended to be stable with increasing distance to the CGDS. The influence range of CGDS on soil seed banks was 300-500 m and was 100-300 m on aboveground vegetation. The CGDS did not affect the vertical distribution pattern of soil seed bank, but significantly affected the horizontal distribution pattern of soil seed banks and aboveground vegetation. The key area of vegetation restoration around the CGDS was between 100 m and 300 m.

Aerobic composting is one of the methods for the resource utilization of submerged plant residues. This study investigated the effects of biochar, wetland sediments and microbial agents added individually or combined on the humification process, lignocellulose degradation and microbial communities during Ceratophyllum demersum and Potamogeton wrightii composting. The results showed that the addition of wetland sediment and biochar was found to significantly elevate the composting temperature and humification of compost products. The average content of lignin in wetland sediment and/or biochar treatments was 12.2–13.5%, which was higher than the control group (10.9–11.45%). Compared with the organic matter (19.4%) and total nitrogen concentration (35.3%) of compost treated with complex microbial agent treatments, the homemade microbial agents significantly increased the values by 22.1% and 41.0%, respectively. By comparing the differences in microbial communities among different treatments, the sediments and homemade agents demonstrated greater increases in activity and diversity of lignocellulose degradation-related microbes, especially for Truepera and Actinomarinale. Humus component and temperature were the most critical parameters influencing the changes in the bacterial community. Based on these results, a combination of biochar and homemade agents was a promising additive for an effective composting strategy, and sediment was identified as a potential control of bacterial diversity in wetland plant compost.

In the coal base of Ningdong,there are many ecological problems associated with the existing local technologies,such as the imperfect technical system,a poor engineering effect,limited generalization value,and the lack of monitoring and evaluation.Based on the screening and integration of the existing technologies in the coal base of Ningdong,we have designed and constructed 14 ecological restoration plots in this study.The 14 plots were composed of two replicates for each of six technical modes and CK treatment(nothing treatment).These technical modes include ecological bag,ecological rod,wire gabion,gravel sand barrier,living sand barrier and wheat straw sand barrier modes.The 14 plots were all constructed in the slope of Yangchangwan waste dump of Ningdong.Several monitoring indicators were selected for vegetation growth observation and data collection,in-cluding erosion amount,runoff amount,runoff depth,richness,coverage,herbal biomass,bush biomass and total biomass.Furthermore,the TOPSIS(Technique for Order Preference by Similarity to Ideal Solution)method was utilized to evaluate the effects of the six ecological restoration modes.The results showed that the wheat straw sand barrier mode area had the best vegetation restoration effect,with coverage of 45%,richness of 1.23 and an aboveground biomass of 0.60 kg m-2.Its monitoring results were 45.16%,43.02%,and 71.43%higher than in the CK,respectively.The gravel sand barrier model presented the least runoff and erosion yield,and its total erosion was 133.46 g m-2 which was only 26.80%of the CK.The runoff amount was 863.32 cm3 m-2,even 50.00%less than CK.The TOPSIS results show that the living sand barrier,gravel sand barrier,and wire gabion modes are the three best ecological restoration modes overall.

分析和优化土地利用碳排放的格局演变可以为构建低碳排放的国土空间格局、助力碳中和战略目标实现提供参考和借鉴.该研究利用土地利用类型、能源消耗和农业活动碳排放系数法,基于GIS软件和PLUS模型核算了河北省2000-2020年土地利用直接碳排放、间接碳排放和净碳排放量及空间格局演变,模拟了自然发展、碳增汇优先发展和碳减排优先发展 3种情景下河北省 2030和 2060年土地利用格局,并核算了生态系统增汇管理下不同情景土地利用碳排放量,结果表明:1)研究期间河北省土地利用直接碳排放量基本保持稳定,表现为碳吸收;土地利用间接碳排放量和土地利用净碳排放量呈现持续增加趋势,但增加速度明显下降.2)研究期间碳吸收区域和中净碳排放栅格单元空间上呈现收缩趋势,低净碳排放、中高净碳排放和高净碳排放栅格单元空间上呈现扩张趋势.碳吸收区域和低净碳排放栅格单元占比最大,但净碳排放主要产生在中高净碳排放区域和高净碳排放栅格单元.3)碳增汇优先发展情景下,林草地分布范围更广,在环渤海区域水域数量明显增加,土地利用直接碳排放绝对值最大.碳减排优先情景下石家庄、唐山、保定等大城市中心城区向外扩张的范围略有收缩,建设用地集约效果有一定体现,土地利用净碳排放值最小.碳减排是未来实现碳中和战略的根本.

Close-to-nature restoration of mining areas is becoming widely recognized for its promotion of ecosystem resilience and risk mitigation of biodiversity losses. Soil seed banks can serve as a direct source of natural restoration, as well as a buffer against environmental changes in vulnerable ecosystem. However, in arid mining area, it remains unclear how the anthropogenic disturbances affect the seed banks and what its potential for vegetation restoration. We conducted a field study to investigate the variation of aboveground plant communities and seed banks along the disturbance gradient in an opencast mining area in arid desert of northwestern China. Furthermore, we detected the influence path of disturbance on seed bank density and richness at different layers. The seed bank had considerable density, with persistent seed accounting for 46%. The density had no significant differences along the none-to-moderate disturbance gradient but decreased significantly at the severe level. Meanwhile, the richness had significant differences among all disturbance levels with the highest value at mild level. There were low similarities between soil seed bank and aboveground vegetation, and their species composition was distinctly different. The anthropogenic disturbances reduced soil seed bank directly. Besides, it indirectly decreased the density of persistent seed bank at shallow layer via the negative impact on silt content. In contrast, disturbance indirectly reduced transient seed density and richness mainly via the positive effect on aboveground vegetation. Briefly, mild-to-moderate disturbance had limited negative effects on the soil seed bank and its restoration potential in the arid mining region. Our study highlights the soil seed banks as supplementary indicator to reflect ecological degradation and the significance for ecosystem recovery. The results could be useful in protection and management projects for the restoration of arid mining areas.

[Objective]The current status and hot trends of slope greening research were studied in order to provide theoretical support and references for subsequent research.[Methods]Professional bibliometric tools CiteSpace and VOSviewer were used to visualize and analyze slope greening research literature indexed by the China National Knowledge Infrastructure(CNKI)database.The main indicators included publication volume,high-frequency keywords,keyword co-occurrence clusters,and burst keywords.The research hotspots and changes in research trends were discussed from three aspects:mechanisms of slope root fixation of soil,selection and configuration of slope plants,and application of engineering greening technology.[Results]There has been a good trend of publishing scientific research results in the field of slope greening in China.Research institutions were mostly higher education institutions(colleges and universities)with programs in the fields of agriculture,forestry,science,and engineering.As a multidisciplinary and comprehensive application technology,slope greening has a very necessary role to play in industry associations.[Conclusion]At present,the variation pattern of slope stability is an important research direction.Numerical simulation technology is expected to play a greater role in the study of slope stability.Plant screening research has focused on the ecological adaptability of plants,which can strengthen future investigations and breeding efforts related to plants adapted to slope protection in the region.Determining the factors influencing plant diversity changes can contribute to the sustainability of plant configuration.Spraying was found to be the most widely used greening technology.The topics of erosion resistance and stability of substrate materials were research hotspots.In the future,it will be necessary to start with the standardization of terminology,construction methods,equipment,and materials so as to gradually establish a standard system for spraying and greening technology applicable to conditions found in China.

Fractional vegetation cover (FVC) is a vital indicator of surface vegetation. Studies of regional vegetation cover are helpful for understanding the status of the regional ecological environment and can provide important references for the formulation of ecological restoration plans and the evaluation of restoration effects. In vegetation cover related research, studies on extraction methods have attracted much attention. Studies have shown that the universality of vegetation cover extraction methods is poor, as well as the existing studies were mostly conducted on agricultural and forest land in wet, semi-humid and semi-arid areas, while few have investigated arid areas with sparse vegetation that is mainly shrubs and grass. To investigate the accuracy and applicability of different methods for estimating vegetation cover in the near-natural zone of the northwest arid desert, this study extracted six vegetation indices (NDVI, SAVI, MSAVI, ARVI, EVI, and MVI), which could effectively exclude soil and meteorological information to obtain pure vegetation information based on GF-2 multispectral-panchromatic fusion images. Two types of models were then established, including the single VI models (DP model) and multi-VI models (R model, RF model and PCA model), three statistics (SSE, r2, RMSE) were introduced to validate model accuracy and four-fold cross-validation was used to probe the models for overfitting. After filtering the models through these methods, the selected model was applied to invert the vegetation coverage in the study area. The results show three key aspects of this system. (1) Among the various models, the DP model constructed using the EVI and the RF model are more suitable for FVC extraction in the study area. This conclusion was further verified by the significant correlation between the inversion results of the FVC for the entire study area by applying these two models. (2) The values of pure bare soil and vegetation pixels (VIs and VIv) in the DP model will obviously affect the accuracy of the model. Thus, the empirical values should not be blindly adopted in actual research. (3) The vegetation distributions in the figures of the FVC results are similar to the outline of the mountains in the study area, indicating that the coverage distribution may be greatly affected by topographic factors. It is recommended that this aspect should be introduced in subsequent studies.

Many problems exist in the ecological restoration of the waste dumps in open-pit mining areas,such as unclear site types of vegetation construction,unsuitable vegetation measures and site conditions,and poor vege-tation growth.To resolve these problems,the site type classification and evaluation of the waste dump in the mining area is a key link to speed up its vegetation reconstruction.In this study,the waste dump in Wuhai treated mining area was selected as the test site.A combination of microtopography,slope direction,mulch thickness,soil hard-ness,soil texture,total phosphorus content,total potassium content,organic matter content,number of vegetation species,and life forms qualitative and quantitative factors were selected.After logarithmic quantification and standardized site factor correlation analysis,principal component analysis,cluster analysis and factor analysis,the site types of the waste dump were classified and evaluated.The results showed that the micro topography,slope direction and mulch thickness were the dominant factors,and they were the main factors influencing vegetation restoration in the study area.According to the combinations of these dominant factors,the waste dump in Wuhai Mining Area was divided into four site type groups and 14 site types.The site quality evaluation of the 14 site types indicated that topographic factors and vegetation factors are the main factors influencing the site quality of the waste dump,and the site quality grades were divided into four relative scores of excellent(comprehensive score greater than 7),good(comprehensive score between 6 and 7),medium(comprehensive score between 5 and 6)and poor(comprehensive score less than 5).Among these grades,50%of the site types had site quality scores of"medium"or"poor",so the overall site quality of the waste dump in Wuhai Mining Area was below the medium level.On this basis,appropriate vegetation allocation suggestions are put forward in order to provide theoretical support for the ecological restoration in an arid open-pit mining area.

Topsoil resources are important resources for ecological restoration in mining areas,although the topsoil stripped in practical projects can not be used for ecological restoration immediately.The changes that occur in topsoil after a certain period of storage in arid areas are not clear,so we have no insight on how to make the best use topsoil for ecological restoration after storage in the mining areas.Therefore,this study investigated the effects of topsoil accumulation on seed density and topsoil nutrient content in seed banks,which could provide a technical basis for vegetation reconstruction of coal mine damaged land in desert areas and theoretical support for ecological restoration practices.In this study,two storage methods of round table piles(hereafter referred to as YT)and cube ton bags(hereafter referred to as DD)were used to preserve uniformly mixed topsoil samples,and the loss of the soil seed bank and nutrient depletion under different topsoil storage methods were analyzed.In the two storage modes,the soil seed density loss on the surface of the pile was the largest,and the loss rate was 79.30%-83.65%.At a given sampling location,soil seed density increased significantly with soil depth(P<0.05).Compared with the change in seed density,soil nutrient loss was less pronounced,and the loss rate was between 8.92%and 16.62%.The seed density loss of the topsoil was the highest in both stacking modes.With the increase in the soil layer,soil seed density was significantly increased(P<0.05).At the same time,there was no significant difference in seed loss between the two storage modes.In the process of preservation,shrub seeds were the most seriously lost in the pile.The nutrient preservation effect of the ton bag storage mode(DD)was better than that of the round table storage mode(YT),and the soil nutrient loss of the top layer of the pile was the greatest,while the soil nutrient losses of other soil layers were lower.

为研究不同生态修复工程下排矸场坡面的恢复效果,以灵武煤矿区典型排矸场为研究对象,通过定量估算生态系统服务价值对生态恢复效果进行评价.根据恢复生态学原理,基于无人机遥感影像对研究区土地利用分类,利用修订后的当量因子法,对灵武煤炭基地中具有代表性的排矸场开采(排弃)占压前、未治理及治理后3个场景的单位面积生态系统服务价值进行估算,并对其生态恢复效果进行评价.灵武排矸场的单位面积生态系统服务价值在开采前、未治理、治理后,总体上经历急剧下降又逐渐提高的过程.其中,价值量最高的为2020年的梅花井排矸场,达到13 372.00元,恢复至78.02％,且气候调节和水文调节为最重要的单项生态系统服务功能.梅花井排矸场生态恢复效果较同地区同类型恢复最好,揭示在西北干旱荒漠煤矿区的生态修复过程中,适宜的生态修复工程是煤矿区排矸场生态恢复、生态系统服务价值提升的重要原因.

对区域土地利用碳排放进行测度有助于优化国土空间布局,为国土空间规划和区域碳补偿/减缓政策制定提供依据.该文基于1995-2018年京津冀区域土地利用和夜间灯光数据,利用碳排放系数和IPCC温室气体排放清单,探究区域土地利用碳排放时空分异特征.结果表明:1)京津冀区域净碳排放量呈现递增趋势,由1995年的12461.78万t C·a-1增至2018年的35706.69万t C·a-1,但增速减缓,其中北京土地利用净碳排放量在2010年达到峰值,天津在2015年达到峰值,河北仍处在增长状态;2)碳吸收区集中分布在西北部燕山—太行山地区,低净碳排放区集中分布在东南平原区,中净碳排放区主要分布在农村居民点和环渤海区域,中高净碳排放区主要分布在北京市主城区,高净碳排放区主要分布在天津市主城区和石家庄、廊坊、保定等城市市区以及部分县域中心城区;3)碳吸收区域和低净碳排放区域面积占比最大,为90％±2％,但碳排放量主要产生在中高净碳排放区域和高净碳排放区域,由1995年的68.41％升至2018年的87.13％.碳减排措施的综合应用是区域实现碳中和的必经之路.

Assessing and predicting the impact of land use/cover changes on ecosystem service supply and demand are crucial to formulating effective sustainable land use policies. In this study, we use the ecosystem service (ES) score matrix, ES supply rate, and ES supply/demand ratio to analyze the supply/demand pattern of ecosystem services based on land use/cover changes in the Beijing-Tianjin-Hebei region from 1990 to 2020. The Conversion of Land Use and Its Effects-Simulation (CLUE-S) model is used to simulate the spatiotemporal patterns of land use change in three scenarios of natural development, ecological priority development, and economic priority development and to predict and simulate the evolution of the ES supply and demand patterns in these different scenarios from 2030 to 2050. It was found that the main land use types are farmland and woodland in the Beijing-Tianjin-Hebei region, accounting for more than 67% from 1990 to 2020, the proportion of farmland decreased from 51.79% to 46.11%, and the proportion of woodland increased from 20.99% to 21.34%; the land use transformation was mainly from farmland to construction land from 1990 to 2020. The supply of ES in the Beijing-Tianjin-Hebei region was at a high level, the supply rate of ES increased from 0.78 to 0.81, the supply/demand ratio of ES decreased from 0.33 to 0.16 from 1990 to 2020, and the supply and demand of ES in the northern and western parts of the Beijing-Tianjin-Hebei region were in surplus. In the natural development scenario, the ES in the Beijing-Tianjin-Hebei region would remain in a high supply state from 2030 to 2050, but the pressure would be greater than before. The deficit, centered on urban construction, would widen, and the ecological situation would deteriorate. In the ecological priority development scenario, the pressure on the ES would be relieved, and the rate of deficit expansion would be reduced. In the economic development priority scenario, the pressure on the ES would increase sharply, and the deficit area would expand rapidly.

The existing slope stability research, which is based on the fluid–solid coupling theory, is mainly focused on the slopes of central and eastern China. The impact of rainfall on the stability of the dump slope has often been ignored. It is worthwhile to reveal the mechanism of the fluid–solid coupling mechanics of dump slopes in the arid desertification area of northwest China under the maximum precipitation. The method of combining the seepage mechanics theory with the geomechanics theory was adopted. Darcy’s law and the mass conservation law were introduced to derive and establish the fluid–solid coupling analysis method. Taking the Xinxing Coal Mine in Wuhai City, China, as an example, the finite element software ABAQUS was used to construct the fluid–solid coupling model for slope stability analysis with unsaturated soil. The equivalent rainfall intensity of 68 mm/h for 1 h and 18 mm/h for 24 h was designed in the simulation, respectively. Four different types of initial water content (i.e., 1.72%, 7.34%, 14.69%, and 22.03%) of the dump slopes were defined as the initial conditions. The high-steep slope was compared to the standard slope. Therefore, a set of sixteen rainfall schemes was proposed. The variation regularity of slope stability was thoroughly discussed in regards to four areas: vertical deformation, pore water pressure distribution, equivalent plastic strain, and safety factor. As was expected, the research showed that the slope height and angle have a significant effect on the slope stability. When high-intensity rainfall occurs for a short duration, the slope tends to be more stable as the initial water content increases on the slope. When low-intensity rainfall occurs over a long period, the slope stability reduces if the initial water content is too high or too low in the slope.

近年来,随着国家煤炭开发产业逐渐西移,干旱荒漠矿区的生态恢复工作愈发受到重视.然而在干旱矿区水资源稀缺的背景下,针对土壤种子库(特别是持久土壤种子库)在天然降水条件下激活情况的研究依然匮乏.本研究以内蒙古乌海市新星露天煤矿周边0?5 cm表层土壤种子库为研究对象,采用人工模拟降水条件下种子库中种子短期萌发试验的方法,对矿区周边持久土壤种子库在不同降水量处理下的萌发进程以及不同日降水量、年降水量对土壤种子库的激活效应进行研究.结果表明:1)不同日降水量对土壤种子库的激活效应存在差异,随着日降水量的增加,激活的土壤种子库物种数和种子萌发数均呈先增加后降低趋势,其中5 mm日降水萌发的种子数最多,10 mm日降水萌发的物种数最多;2)不同植物种子对不同日降水量的响应状态不同,种子萌发数量最多的小画眉草(Eragrostis minor)、冷蒿(Artemisia frigida)在3～20 mm日降水均能被激活,而红砂(Reaumuria songarica)、猫头刺(Oxytropis aciphylla)等灌木种子需在10 mm以上降水量才能被激活;3)在50～150 mm年降水量范围,激活的种子数量占土壤种子库储量的16.46％～68.52％,激活的物种数占土壤种子库物种总数的25.00％～62.50％,二者均呈先增加后稳定的趋势.不同年降水量下,土壤种子库萌发的物种组成和群落结构差异显著(P<0.05).

针对目前荒漠煤矿区排土场治理技术单一、配套措施不完备、缺乏效果好和低成本的生态恢复对位配置技术模式等问题,以内蒙古乌海已治理的14座排土场为研究对象,进行野外植被调查和土壤取样分析,选取13项指标从植被恢复、土壤改良和经济性3个层面构建评价体系,结合主成分和熵权法确定指标权重,进行技术模式综合评价,筛选最佳生态修复对位配置技术模式,并提出应用建议.结果表明:1)荒漠煤矿区不同立地类型对位配置技术包括砾石压盖、沙柳网格、毯帘护坡、砖砌方形/拱形骨架和密目网覆盖等坡面防护措施;生态袋截排水、干砌石截水沟和波纹管排水等截排水措施;2)毯帘覆盖+生态袋排水+播种模式在中层陡阴阳坡、中层急阴阳坡和中层陡阴坡等立地类型均适宜推广;3)砖砌方形/拱形骨架恢复效果不同是由于布设规格及施工质量差异导致.由此得出结论:1)阴坡土壤水分消耗较少,蒸腾作用弱,更有利于植被恢复;2)砖砌方形/拱形骨架相比于毯帘覆盖,更有利于土壤中有机碳和氮素的积累.