Search Results (75)

The Inner Mongolia Plateau (IMP), situated in the arid and semi-arid ecological transition zone of northern China, is particularly vulnerable to both climate change and human activities. Understanding the spatiotemporal vegetation dynamics and their driving forces is essential for regional ecological management. This study employs Sen’s slope estimation, BFAST analysis, residual trend method and Geodetector to analyze the spatial patterns of Normalized Difference Vegetation Index (NDVI) variability and distinguish between climatic and anthropogenic influences. Key findings include the following: (1) From 1982 to 2022, vegetation cover across the IMP exhibited a significant greening trend. Zonal analysis showed that this spatial heterogeneity was strongly regulated by regional hydrothermal conditions, with varied responses across land cover types and pronounced recovery observed in high-altitude areas. (2) In the western arid regions, vegetation trends were unstable, often marked by interruptions and reversals, contrasting with the sustained greening observed in the eastern zones. (3) Vegetation growth was primarily temperature-driven in the eastern forested areas, precipitation-driven in the central grasslands, and severely limited in the western deserts due to warming-induced drought. (4) Human activities exerted dual effects: significant positive residual trends were observed in the Hetao Plain and southern Horqin Sandy Land, while widespread negative residuals emerged across the southern deserts and central grasslands. (5) Vegetation change was driven by climate and human factors, with recovery mainly due to climate improvement and degradation linked to their combined impact. These findings highlight the interactive mechanisms of climate change and human disturbance in regulating terrestrial vegetation dynamics, offering insights for sustainable development and ecosystem education in climate-sensitive systems. Full article

Given the increasing challenges posed by frequent extreme climatic events, understanding the climate–human connection between the climate system and the transitions of ancient civilizations is crucial for addressing future climatic challenges, especially when examining the relationship between the abrupt events of the Holocene and the Neolithic culture development. Compared with the globally recognized “4.2 ka collapse” of ancient cultures, the initial start time and the cultural significance of the 5.5 ka climatic fluctuation are more complex and ambiguous. The Hongshan culture (6.5–5.0 ka) is characterized by a complicated society evident in its grand public architecture and elaborate high-status tombs. However, the driving mechanisms behind cultural changes remain complex and subject to ongoing debate. This paper delves into the role of climatic change in Hongshan cultural shifts, presenting an integrated dataset that combines climatic proxy records with archaeological data from the Hongshan culture period. Based on synthesized aeolian, fluvial-lacustrine, loess, and stalagmite deposits, the study indicates a relatively cold and dry climatic fluctuation occurred during ~6.0–5.5 ka, which is widespread in the Horqin dune field and adjacent areas. Combining spatial analysis with ArcGis 10.8 on archaeological sites, we propose that the climatic fluctuation between ~6.0–5.5 ka likely triggered the migration of the Hongshan settlements and adjustment of survival strategies. Full article

Wind erosion poses a major threat to ecosystem stability and land productivity in arid and semi-arid regions. Accurate identification of its spatiotemporal dynamics and underlying driving mechanisms is a critical prerequisite for effective risk forecasting and targeted erosion control. This study applied the Revised Wind Erosion Equation (RWEQ) model to assess the spatial distribution, interannual variation, and seasonal dynamics of the Soil Wind Erosion Modulus (SWEM) across Inner Mongolia from 1990 to 2022. The GeoDetector model was further employed to quantify dominant drivers, key interactions, and high-risk zones via factor, interaction, and risk detection. The results showed that the average SWEM across the study period was 35.65 t·ha⁻¹·yr⁻¹ and showed a decreasing trend over time. However, localised increases were observed in the Horqin and Hulun Buir sandy lands and central grasslands. Wind erosion was most intense in spring (17.64 t·ha⁻¹·yr⁻¹) and weakest in summer (5.57 t·ha⁻¹·yr⁻¹). Gale days, NDVI, precipitation, and wind speed were identified as dominant drivers. Interaction detection revealed non-linear synergies between gale days and temperature (q = 0.40) and wind speed and temperature (q = 0.36), alongside a two-factor interaction between NDVI and precipitation (q = 0.19). Risk detection indicated that areas with gale days > 58, wind speed > 3.01 m/s, NDVI < 0.2, precipitation of 30.17–135.59 mm, and temperatures of 3.01–4.23 °C are highly erosion-prone. Management should prioritise these sensitive and intensifying areas by implementing site-specific strategies to enhance ecosystem resilience. Full article

Afforestation with Pinus sylvestris var. mongolica in northern China is hindered by soil degradation. This study evaluated a ternary amendment combining sewage sludge (SS), cattle manure (CM), and maize straw (MS) to rehabilitate degraded sandy soils in the Horqin Sandy Land. Five treatments were tested: control (CK), SS (T1), SS + CM (T2), SS+MS (T3), and SS + CM + MS (T4). The ternary amendment (T4) achieved optimal outcomes: soil pH decreased from 8.02 to 7.79, organic carbon increased 2.5–fold, and total nitrogen (127%) and phosphorus (87.5%) were enhanced compared to CK. Pinus sylvestris exhibited a 65.6% greater basal diameter and 29.5% height increase under T4, while heavy metal concentrations (Cd: −54.6%, Cu: −35.1%, Pb: −12.2% and Zn: −27.6%) were reduced. These findings highlight a synergistic waste valorization strategy for dryland afforestation, balancing soil fertility improvement with ecological safety. Future studies should prioritize long-term microbial community dynamics and field-scale validation. Full article

In recent years, bifunctional ingredients extracted and utilized from waste by-products as raw materials have received significant attention in the food production process. Previous studies have found that bovine livers possess both antioxidant and emulsifying potential; therefore, enhancing these dual properties is a current research focus. In this study, three different types of polyphenols (epigallocatechin gallate [EGCG], gallic acid [GA] and tannin [TA]) provide a reference on how to achieve better complexation of polyphenols with bovine liver hydrolysates (BLHs). Based on the molecular weight results, it was shown that the bovine liver peptides bind to polyphenols to form complexes with higher molecular weights. Furthermore, the binding affinities among the three complexes were as follows: TA > EGCG > GA. The emulsions stabilized by the coupling compounds contained more homogeneous and dense droplets (optical microscopy). Both the antioxidant properties and the emulsifying activity of all complexes were superior to those of bovine liver hydrolysates (BLHs) (p < 0.05), confirming synergistic effects that either flavonoids, phenolic acids or tannins possess with bovine liver hydrolysates. This combination provides an effective strategy for developing novel foods with specific functions. Full article

The capacity to develop resilience to global change, such as nitrogen deposition, is an important topic for the management of key ecological functional zones. In this study, nitrogen enrichment (10 g N m⁻² yr⁻¹, NE) and control plots (0 g N m⁻² yr⁻¹, CL), each with eight replications, were randomly established in the Horqin Sandy Land to investigate how grassland carbon sequestration functions and herdsmen’s livelihoods respond to nitrogen deposition. In addition, three grazing scenarios (non-grazing, light grazing, and moderate grazing) were simulated to determine whether human activities affect the relationships (trade-off vs. synergistic) among forage supply, carbon sequestration, and windbreak and sand-fixing services under nitrogen deposition. The results showed that NE exhibited a significant increase in aboveground carbon storage (99.40 g C m⁻², 117.34%) and the shoot carbon/root carbon ratio (1.90) when compared to the CL (0.95) (p < 0.05). NE significantly decreased soil carbon storage ability, particularly in the 10–30 cm soil layer (p < 0.05). The reduction in soil carbon storage was offset by increases in plant carbon storage, resulting in a neutral effect of the NE treatment on the total grassland carbon storage (p > 0.05). The synergistic effects of NE on grassland forage supply and windbreak and sand-fixing functions were observed under a light grazing scenario, which balanced ecological safety and livelihood more effectively than the non-grazing and moderate grazing scenarios. These findings indicate that the structure of grassland carbon storage is influenced by nitrogen deposition and that light grazing would enhance ecosystem services and promote sustainable grassland development. Full article

Transforming land use patterns prevents and controls desertification. In the Horqin Sandy Land, we evaluated the soil restoration effects of planting corn (from 2014 to 2018) on previously uncultivated land (in 2013), followed by the transition to alfalfa cultivation under five nitrogen application levels (from 2019 to 2023). After corn cultivation, the soil available nitrogen (AN), C/N ratio, C/P ratio, and N/P ratio decreased by 39.02%, 7.14%, 21.35%, and 12.83%, respectively, compared to those of uncultivated land. However, following the planting of alfalfa, especially in 2023, the bulk density values were the lowest, while the AN, soil organic carbon, total nitrogen, and total phosphorus values were the highest. An AHP-fuzzy comprehensive evaluation showed that the available phosphorus (AP), SOC, C/N, C/P, and N/P had significant weights of 0.12, 0.128, 0.133, and 0.128, respectively, and thus were key soil quality determinants. The soil quality assessment values for the N1 and N2 treatments were the highest at 0.208 and 0.202, respectively. Conclusively, the intensive cultivation of alfalfa under 51.75 and 103.5 kg/ha N improves soil fertility. This study provides theoretical support for the restoration of desertified soils in the Horqin Sandy Land. Full article

Water use efficiency (WUE), as an important metric for ecosystem resilience, has been identified to play a significant role in the coupling of carbon and water cycles. The farming–pastoral ecotone of Northern China (FPENC), which is highly susceptible to drought due to water scarcity, has long been recognized as an ecologically fragile zone. The ecological restoration projects in China have mitigated land degradation and maintain the sustainability of dryland. However, the process of greening in drylands has the potential to impact water availability. A comprehensive analysis of the WUE in the FPENC can help to understand the carbon absorption and water consumption. Using gross primary production (GPP) and evapotranspiration (ET) data from a MODerate resolution Imaging Spectroradiometer (MODIS), alongside biophysical variables data and land cover information, the spatio-temporal variations in WUE from 2003 to 2022 were examined. Additionally, its driving force and the ecosystem resilience were also revealed. Results indicated that the annual mean of WUE fluctuated between 0.52 and 2.60 gC kgH₂O⁻¹, showing a non-significant decreasing trend across the FPENC. Notably, the annual averaged WUE underwent a significant decline before 2012 (p < 0.05), and then showed a slight increased trend (p = 0.14) during the year afterward (i.e., 2013–2022). In terms of climatic controls, temperature (Temp) and soil volumetric water content (VSWC) dominantly affected WUE from 2003 to 2012; VPD (vapor pressure deficit), VSWC, and Temp showed comprehensive controls from 2013 to 2022. The findings suggest that a wetter atmosphere and increased soil moisture contribute to the decline in WUE. In total, 59.2% of FPENC was shown to be non-resilient, as grassland occupy the majority of the area, located in Mu Us Sandy land and Horqin Sand Land. These results underscore the importance of climatic factors in the regulation WUE over FPENC and highlight the necessity for focused research on WUE responses to climate change, particularly extreme events like droughts, in the future. Full article

Biochar is increasingly being applied to improve various degraded soils. However, studies on its use in ameliorating saline–alkaline grasslands remain limited. This study conducted experimental trials using soil collected from an alkalized meadow grassland in the Horqin Steppe, applying biochar with the application rates of 0, 1.5, 3.0, and 4.5 kg/m² in planting boxes. The objectives were to evaluate the effects of biochar addition on soil properties and microbial community and to explore the feasibility of using biochar for alkalized grassland improvement. Biochar addition to alkalized meadow soil enhanced the biomass of planted Astragalus adsurgens and improved soil properties. Soil bulk density was reduced; porosity, moisture content, and field moisture capacity significantly increased; soil nutrients were significantly ameliorated. Simultaneously, soil enzyme activities, including urease, phosphomonoesterase, protease, and polyphenol oxidase, significantly increased. Biochar application altered the microbial community structures in the alkalized meadow soil, primarily through the shifts in the relative abundance of dominant taxa rather than the fundamental changes in dominant phyla or genera. Biochar addition significantly raised the abundance of phoD- and nifH-harboring microorganisms, suggesting the enhancement in functions of soil N fixation and P transformation. Key factors influencing bacterial community structure included electrical conductivity, total P, total K, bulk density, and available K, whereas fungal communities were primarily affected by bulk density, porosity, and available N. Excessive biochar application can diminish its yield-enhancing effects, and the recommended biochar application rate for alkalized meadow grasslands in practice is 1.5 kg/m². These findings are expected to provide experimental evidence for utilizing biochar in degraded grasslands improvement. Full article

Alfalfa (Medicago sativa L.) plays a crucial role in the revitalization of the dairy industry and grassland agriculture in China. However, regional differences in economic and environmental performance have not been adequately specified or quantified. This study compares alfalfa production in Wuhe County (Southern China) and Ar Horqin Banner (Northern China) by integrating cost–benefit analysis (CBA) with life cycle assessment (LCA). Field data from 22 enterprises were analyzed using one ton of alfalfa hay and a net profit of CNY 10,000 as functional units, over a three-year evaluation period (2017–2019). The assessment encompassed four impact categories: primary energy demand (PED), global warming potential (GWP), acidification potential (AP), and water use (WU). The northern case systems exhibited 67.45% higher production costs but 96.99% greater profitability per ton compared to the southern case, alongside 2.13 × 10⁻² greater environmental impact. Conversely, the southern case systems were less profitable and demonstrated an 18.6% higher environmental impact per CNY 10,000 net profit compared to the northern case. Regional environmental hotspots differed: fertilizer use dominated impact in the south, whereas irrigation and electricity consumption drove burdens in the north. To facilitate a sustainable transition, policymakers should implement region-specific support measures, such as ecological incentives and crop rotation schemes for the south, and water-saving technologies along with renewable energy integration for the north. Farmers and enterprises are encouraged to adopt precision input strategies and climate risk management tools, while researchers should focus on advancing adaptive breeding techniques and optimizing resource utilization. The development of a unified system that integrates economic and environmental metrics is crucial for enabling stakeholders to drive the sustainable transformation of alfalfa production. Full article

Soil microorganisms play key roles in soil phosphorus (P) mobilization in grassland ecosystems. However, little is known about how bacterial communities involved in P transformation respond to soil secondary salinization. In this study, a meadow grassland with a gradient of secondary salinization in the semi-arid Horqin Sandy Land, Northeast China was selected. Soil properties, P fractions, the P transformation potentials, the community structures, and the abundance of a phosphorus (P)-mineralizing gene (phoD) and a P-solubilizing gene (gcd) were determined. NaHCO₃-Pi and NaOH-Pi declined with salinization, whereas H₂O-P, NaHCO₃-Po, and HCl-Pi increased. However, the available P fractions (H₂O-P and NaHCO₃-Pi) remained largely unaffected. Soil salinization significantly decreased the relative abundance of Xanthomonadales and Caulobacterales and increased that of Pseudonocardiales and Enterobacterales. The P fractions, the abundance of the phoD and gcd genes, and the community structures were all closely associated with soil organic matter, total nitrogen, pH, and soil moisture. Additionally, the structures of the phoD and gcd communities were significantly correlated with NaHCO₃-Pi and NaOH-Pi. Overall, secondary salinization altered bacterial communities related to P transformation by modifying soil properties, leading to decreases in the labile P and moderately labile P fractions. Full article

Land-use changes in meadow grasslands in semi-arid areas usually significantly affect soil environment and microbiota. However, studies on the response of soil P-cycle-related microbial communities to land-use conversions are still limited. In this study, a series of land-use types including upland field, paddy field, poplar plantation, and their adjacent natural meadow grassland in the Horqin Sandy Land of Northeast China were selected, and the diversities and structures of soil microbial communities involved in organic P mineralization (phoD-harboring community) and inorganic phosphate solubilization (gcd-harboring community) were investigated by the high-throughput sequencing technique. Land-use type had significant influences on soil physicochemical properties, enzymatic activities, and P conversion rates, thereby altering the structures of soil gcd and phoD communities. Soil phoD microbes are more abundant and have more contributions to available P than gcd microbes. The responses of gcd or phoD communities to land-use type were characterized as the quantitative shift in the relative abundance of dominant taxa; however, the basic compositions of the two communities were slightly affected. Soil pH, EC, and nutrient contents (including organic matter and total and available N, P, and K) all significantly affected soil gcd and phoD microbial communities. The abundance of phoD and gcd genes varied with land-use type and could be used as indicators for estimating the bioavailability of soil P. Full article

Correctly understanding existing plantations and improving the cycles and effects of ecological restoration in sandy areas have become important scientific issues. Consequently, we selected different diameters at breast height (DBHs) for Populus spp. and Pinus sylvestris var. mongolica (P. sylvestris var. mongolica) and varying diameters at the base (DBs) of Caragana microphylla Lam. (C. microphylla) as research subjects in the sandy plantations in northwestern Liaoning Province. Soil samples were collected along a gradient at distances of 20 cm, 60 cm, and 120 cm from the tree base. Our objective was to investigate the connections among various afforestation species, DBHs or DBs (age), and soil nutrients. The results from our study area revealed that (1) the soil nutrient contents were extremely low; (2) the DBHs or DBs were not significantly related to soil exchangeable phosphorus (EP), total potassium (TK), or Pondus Hydrogenii (pH) but had a significant or moderately positive correlation with soil organic carbon (SOC), exchangeable potassium (EK), total nitrogen (TN), total carbon (TC), and total phosphorus (TP). The most significant relationship was with EK at a distance of 20 cm from the tree base; (3) the three afforestation species presented different trends in terms of the soil nutrient contents among the different distances from the tree base; and (4) the EK in the Populus spp. plantations was significantly greater than that in the P. sylvestris var. mongolica plantations and moderately significantly greater than that in the C. microphylla plantations. The pH levels in P. sylvestris var. mongolica plantations were significantly lower than those in Populus spp. plantations and C. microphylla plantations. Our study provides valuable insights into the synergistic development between sandy plantations and soil dynamics. This study provides important evidence for selecting suitable plant species for vegetation restoration and improvement efforts in sandy lands. Full article

The goal of this study is to analyze the land use and land cover change (LUCC) in the Northeast Sandy Land from 1990 to 2023 and reveal the characteristics of the changes in the value of ecosystem services in the area, aiming to provide scientific references for the ecological sustainable development of the Northeast Sandy Land. Using Landsat series remote sensing images from 1990 to 2023, we endeavored to obtain the information mapping of LUCC in the study area in four periods (1990, 2000, 2010, and 2023), applied GIS spatial analysis and numerical statistical analysis methods to study the LUCC in the area, and calculated the resulting changes in ecosystem service value (ESV) based on the table of ESV coefficients. The results show that: (1) in the past 33 years, LUCC in the Northeast Sandy Land has changed significantly, with an increase in the area of farmland, sandy land, and other lands, and a decrease in the area of forest, grassland, and water; (2) the value of ecosystem services has increased from CNY 1,624,557.77 billion in 1990 to CNY 173,999.99 billion in 2023, the average annual growth rate is 0.24%/a; (3) in the single ESV, the ESV of biodiversity increase is the greatest, with an increase of 0.72%/a; (4) LUCC is obvious in the Northeast Sandy Land, and LUCC is the main reason affecting the change in regional ESV. Full article

The Horqin Sandy Land in China is a key alfalfa production base, challenged by low winter temperatures and large diurnal temperature shifts, affecting alfalfa’s winter survival. Alfalfa roots are the primary organs responsible for winter adaptability; consequently, by investigating the changes in the root physiology and nutritional components of alfalfa during the overwintering period, we can enhance our understanding of its mechanisms for cold resistance. Over the course of two years (2022–2023), field trials were conducted on 40 alfalfa varieties selected from both domestic and international sources for their potential cold resistance. This study assessed winter survival rates and analyzed root contents, including soluble sugars, starch, soluble proteins, and the concentrations of carbon (C), nitrogen (N), phosphorus (P) and their stoichiometric ratios. Principal component analysis, subordinate function analysis, and cluster analysis were employed for comprehensive evaluation. Biochemical markers varied significantly across varieties. The C, N, and starch contents in the roots were the main factors determining cold resistance. The varieties were categorized into four groups: Category I included five highly resistant varieties (‘Baimu 202’, ‘WL168HQ’, ‘Zhongmu No. 1’, ‘Gongnong No. 1’, and ‘Legacy’); Category II consisted of six moderately resistant varieties; Category III included twenty-eight slightly resistant varieties; and Category IV contained one non-resistant variety (‘3010’). This study recommends the adoption of the five varieties in Category I to enhance alfalfa cultivation in the Horqin region. This research provides valuable theoretical and practical guidance for improving the cultivation of alfalfa in the cold regions of northeastern China, supporting the development of the local livestock industry. Full article