Search Results (124)

The Grain for Green Program (GGP), one of the world’s largest soil and water conservation initiatives, has been implemented in China as a representative payment for environmental service program. This study aims to evaluate the ecosystem service value (ESV) of forests established under the GGP in five representative provinces (Hebei, Liaoning, Hubei, Yunnan, Gansu), using a systematic methodology that integrates ecologic and economic dimensions for large-scale ecological projects. Between 1999 and 2013, a total of 717.67 × 10⁴ ha of forests were established. Barren land served as the primary land source, with ecological forest being the dominant forest type within the program. The ESV assessment encompassed key services, including water conservation, soil conservation, carbon sequestration, nutrient retention, air quality improvements, and biodiversity improvements. Based on our estimates, the total annual ESV of the afforested areas under GGP in the five representative provinces is 3604.99 × 10⁸ Yuan, with water conservation representing the largest share among all ecosystem services. Moreover, the cumulative ESV generated by these forests over the 14-year period exceeded the total payments made by the central government to farmers. To ensure the long-term success and sustainability of the GGP, a more equitable cost–benefit sharing mechanism is recommended. Full article

As a critical ecological barrier and key dryland agricultural zone in China, the Loess Plateau is faced with acute tensions between food security risks arising from cropland abandonment (CA) and the imperatives of ecological conservation. Yet, existing research has failed to adequately capture the long-term, high-spatiotemporal-resolution dynamics of abandonment in this region or to quantitatively couple its driving mechanisms with implications for food security. To address these gaps, this study establishes a high-precision identification system for CA tailored to the Plateau’s complex topographic conditions, distinguishing among interannual abandonment, multiyear abandonment, conversion to forest/grassland, and reclamation. Leveraging long-term data from 2000 to 2023 and integrating the Mann–Kendall test with the random forest algorithm, we examine the spatiotemporal trajectories, driving forces, and food security consequences of CA. Guided by a “type differentiation–grade classification–temporal tracking” framework, the analysis reveals a marked transition in dominant drivers from “socioeconomic factors” to “topographic–climatic factors.” It further identifies an “increasing loss–slowing growth” effect of abandonment on grain production, alongside a “pressure alleviation” trend in per capita carrying capacity. The results showed that: (1) Between 2000 and 2023, the area of CA on the Loess Plateau expanded from 2.72 million ha to 6.96 million ha, with high-grade abandonment (≥8 years) accounting for 58.9% of the total and being spatially concentrated in the hilly–gully regions of northern Shaanxi and eastern Gansu; (2) The Grain for Green Project (GFGP) peaked at approximately 340,000 hectares in 2018, followed by a slight decline, but has generally remained at around 300,000 hectares since then; (3) The reclamation rate of CA remained between 5% and 12% during 2003–2015, with minimal overall fluctuations, but after 2016, it gradually increased and peaked at 23.4% in 2022; (4) In terms of driving forces, population density (14.99%) was the primary determinant in 2005, whereas by 2020, slope (15.43%) and mean annual precipitation (15.63%) emerged as core factors; and (5) Grain yield losses attributable to abandonment increased from less than 100 t to nearly 450 t, though the growth rate slowed after 2016, accompanied by gradual alleviation of pressure on per capita carrying capacity. Overall, the study offers robust empirical evidence to inform cropland protection, food security strategies, and sustainable agricultural development policies on the Loess Plateau. Full article

The fragile karst ecosystem in Southwest China faces severe water scarcity. Since 2000, large-scale ecological restoration programs (e.g., the “Grain for Green” Program) have substantially increased vegetation coverage. Concurrently, climate change has manifested as a distinct warming trend and heightened drought risk in recent decades. Therefore, understanding the synergistic and competing effects of climate change and vegetation restoration on regional evapotranspiration (ET) is critical for projecting water budgets and ensuring the sustainability of ecosystems and water resources within this vital ecological barrier region. This study employs a dual-scenario PT-JPL model (simulating natural vegetation dynamics versus constant coverage) integrated with Sen + MK trend analysis to quantify the spatiotemporal patterns of ET and its components—canopy transpiration (ETc), interception evaporation (ETi), and soil evaporation (ETs)—in Southwest China’s karst region (2000–2018). Furthermore, multiple regression analysis and SEM were utilized to investigate the driving mechanisms of vegetation and climatic factors (temperature, precipitation, radiation, and relative humidity) on changes in ET and its components. The key results demonstrate the following: (1) Vegetation restoration exerted a net positive effect on total ET (+0.44 mm/a) through enhanced ETi (+0.22 mm/a) and ETs (+0.37 mm/a), despite reducing ETc (−0.08 mm/a), revealing trade-offs in water allocation. (2) Radiation dominated ET variability (66.45% of the area exhibiting >50% contribution), while temperature exhibited the most extensive spatial dominance (44.02% of the region), and relative humidity exhibited drought-mediated dual effects (promoting ETi while suppressing ETc). (3) Precipitation exhibited minimal direct influence. Vegetation restoration and climate change collectively drive ET dynamics, with ETc declines indicating potential water stress. These findings elucidate the synergistic regulation of vegetation restoration and climate change on karst ecohydrology, providing critical insights for water resource management in fragile ecosystems globally. Full article

Since the launch of the Grain for Green (GFG) program in 1999, the Loess Plateau has undergone significant vegetation changes. However, the driving mechanisms behind these changes in the post-GFG period remain insufficiently understood. This study analyzes the spatiotemporal dynamics of vegetation on the Loess Plateau from 1982 to 2015, based on long-term NDVI time series, and quantitatively identifies the relative contributions of climate variability and human activities using partial correlation and multiple regression residual analysis. The results reveal a significant increase in NDVI after 2000, with the annual variation rate rising from 0.0009 to 0.0028, and the proportion of rapidly greening areas expanding from 13.3% to 62.9%. Spatially, vegetation recovery was more prominent in the eastern and lower-latitude regions. While both climate and anthropogenic factors influenced vegetation changes, the latter became dominant after 2000. The area where human activities significantly enhanced vegetation increased from 1.9% to 60.6%, with the most notable improvements observed in forests, followed by croplands and grasslands. Vegetation in the southern plateau was more sensitive to temperature, while the northern region responded more strongly to precipitation. From 2000 to 2015, the GFG program contributed to increases of 17,059.46 km² in grasslands and 10,105.78 km² in forests. These findings improve our understanding of vegetation change drivers on the Loess Plateau and offer a scientific basis for ecological restoration, policy-making, and sustainable development in the Yellow River Basin. Full article

Understanding the tradeoff and synergy among ecosystem services (ESs) and their influencing factors is a prerequisite for simultaneously managing multiple ESs and holds significant importance for achieving harmonious regional development between humans and nature. Existing research predominantly focuses on the overall characteristics of tradeoff and synergy, while studies on spatially differentiated tradeoff and synergy characteristics remain limited. In addition, their driving mechanisms are not yet fully understood, especially in large-scale river basins. This study, taking the Yellow River Basin (YRB) from 2000 to 2023 as the study area, employed multi-source data and multiple models to quantify three ESs, including soil erosion negative service (indirectly reflecting the soil conservation service function), carbon sequestration, and water yield. Combining Pearson correlation analysis, a geographically weighted regression model, and optimal parameter geographical detection, we identified the spatiotemporal interaction relationships and their dominant drivers. The results indicated that soil erosion negative services decreased by 24.89%, while carbon sequestration and water yield increased by 53.30% and 38.47%, respectively. The most significant improvements in the three ESs were observed in the midstream of the YRB. Spatially, soil erosion negative service decreased from west to east. Carbon sequestration exhibited a spatial pattern of higher values in the south and east and lower values in the north and west. Water yield decreased from south to north. Tradeoff relationships existed between soil erosion negative service and carbon sequestration and between soil erosion negative service and water yield. A synergistic relationship existed between carbon sequestration and water yield. Over time, the proportion of areas showing synergy among these three ESs decreased. However, synergistic areas remained more common than tradeoff areas. This was especially evident in the relationship between carbon sequestration and water yield, where synergy consistently accounted for over 78% of the YRB. Rainfall, soil properties, and fractional vegetation cover were identified as important drivers of the tradeoff/synergy between soil erosion negative service and carbon sequestration. Rainfall, temperature, fractional vegetation cover, and elevation were significant drivers of the interactions between carbon sequestration and water yield. Population density, fractional vegetation cover, GDP density, and rainfall were the main influencing factors for the tradeoff/synergy between soil erosion negative service and water yield. Our general methodology and results provide valuable decision-making references for policymakers, highlighting the necessity of considering the spatiotemporal heterogeneity in ESs tradeoff characteristics and their underlying driving factors. Full article

Karst regions, characterized by thin soil layers, severe rocky desertification, and fragile vegetation, hold significant scientific value for achieving China’s “dual-carbon” goals. This study focuses on Zhijin County in Guizhou Province, integrating provincial carbon density data with forest resource inventory data. By constructing a model to adjust aboveground forest carbon density (AGC) estimation parameters and utilizing the InVEST model alongside hotspot analysis, the research systematically examines the spatiotemporal heterogeneity of carbon storage from 2000 to 2020. These findings provide actionable strategies for enhancing carbon sequestration efficiency in ecologically fragile regions, supporting China’s “dual-carbon” policy goals. Key findings include: (1) Carbon storage exhibits a “growth-turning point” two-phase pattern, increasing by 0.46% from 2000 to 2015 but decreasing by 3.31% in 2020 due to construction land expansion. (2) There are significant differences in carbon storage among ecological engineering projects, with the highest carbon storage found in the “Grain-for-Green Program” project area and the lowest in the “National Rocky Desertification Control Program” area. (3) Elevation is the primary controlling factor for carbon storage, with rocky desertification showing notable spatial differentiation. This study provides theoretical support for the precise regulation of ecological programs and the development of high-precision carbon storage models in karst regions. Full article

Oat is a dual-purpose crop valued for both grain and forage. The stay-green (SG) trait, which delays leaf senescence and prolongs photosynthesis, has been shown to increase yield and quality in several crop species, yet its performance across diverse environments in oats remains underexplored. In this study, multi-location field trials were conducted in Ledu, Huangzhong and Haiyan, Qinghai Province, China, to comprehensively evaluate the performance of stay-green oat lines. The traits evaluated included grain yield components, nutritional quality, and seedling establishment traits. A TOPSIS (technique for order preference by similarity to an ideal solution) model, coefficient of variation (CV) and G × E (genotype × environment) visualization were used to assess adaptability, stability, and genotype × environment interactions. On average, the stay-green lines exhibited an 16.00% increase in plot yield and a 22.93% increase in thousand-grain weight compared to controls. Notable improvements were also observed in the starch (7.58% LN_SG in HZ and HY) and protein (3.58%, QY5_SG all the sites) contents, as well as multiple seedling establishment indices, with the seedling vigor indices increasing by more than 50%. Stability analysis further showed that the stay-green lines were stable in spike length, thousand-grain weight, water-soluble carbohydrates, and seed and seedling vigor. TOPSIS analysis identified ‘LN_SG’ as the top-performing and most adaptable genotype across all environments. Overall, stay-green oat lines demonstrated superior performance in grain yield, nutritional quality, and seedling establishment. These findings highlight their potential for field application and their value as parental materials in oat breeding programs enhancing environmental adaptability and stability. Full article

Sorghum (Sorghum bicolor, (L.) Moench.), is one of the most important cereals in semi-arid and subtropical regions of Africa. However, in these regions, sorghum cultivation is often faced with several constraints. In Mali, terminal or post-flowering drought, caused by the early cessation of rains towards the end of the rainy season, is one of the most common constraints. Sorghum is generally adapted to harsh conditions. However, drought combined to heat reduce its yield and production in tropical and subtropical regions. To identify parents of sorghum hybrids tolerant to post-flowering drought for commercial hybrids development and deployment, a total of 200 genotypes, including male and female parents of the hybrids, were evaluated in 2022 by lysimeters under two water regimes, well-irrigated and water-stressed, at ICRISAT in Niger. Agronomic traits such as phenological stages, physiological traits including transpiration efficiency, and morphological traits such as green leaf number were recorded. Genotype × environment (G × E) interaction was significant for harvest index (HI), green leaf number (GLN), and transpiration efficiency (TE), indicating different responses of genotypes under varying water conditions. Transpiration efficiency (TE) was significantly and positively correlated with total biomass (BT), harvest index (HI), and grain weight (GW) under both stress conditions. Genotypes ICSV216094, ICSB293, ICSV1049, ICSV1460016, and ICSV216074 performed better under optimal and stress conditions. The Principal Component Analysis (PCA) results led to the identification of three groups of genotypes. The Groups 1 and 3 are characterized by their yield stability and better performance under stress and optimal conditions. These two groups could be used by breeding programs to develop high yield and drought tolerant hybrids. Full article

Soil potentially toxic element (PTE) contamination remains a global concern, particularly in rural agricultural regions. This study collected 157 agricultural topsoil samples within a rural area in SW China. Combined with multivariate statistical analysis in the compositional data analysis (CoDa) perspective, the PMF model was applied to identify key contamination sources and quantify their contributions. Potential ecological risk assessment and Monte Carlo simulation were employed to estimate ecological-health risks associated with PTE exposure. The results revealed that the main exceeding PTEs (Mercury—Hg and Cadmium—Cd) are rich in urbanized areas and the GFGP (Grain for Green Program) regions. Source apportionment indicated that soil parent materials constituted the dominant contributor (32.48%), followed by traffic emissions (28.31%), atmospheric deposition (21.48%), and legacy agricultural effects (17.86%). Ecological risk assessment showed that 60.51% of soil samples exhibited higher potential ecological risk (PERI > 150), with moderate-risk areas concentrated in the GFGP regions. The elements Cd and Hg from legacy agricultural effects and atmospheric deposition contributed the most to ecological risk. Health risk assessment demonstrated that most risk indices fell within acceptable ranges for all populations, while only children showed elevated non-carcinogenic risk (THI_max > 1.0). Among PTEs, the element As, mainly from traffic emissions, was identified as a priority control element due to its significant health implications. Geospatial distributions showed significant risk enrichment in the GFGP regions (legacy agricultural areas). These findings present associated risk levels in sustainable agricultural regions, providing valuable data to support soil environmental management in regions requiring urgent intervention worldwide. Full article

Aboveground biomass (AGB) serves as a crucial indicator of the effectiveness of the Grain for Green Program (GGP), and its accurate estimation is essential for evaluating forest health and carbon sink capacity. However, due to the dominance of sparse forests in GGP stands, research in this area remains significantly limited. In this study, we developed the optimal tree height-diameter at breast height (DBH) growth models for major tree species and constructed a high-quality AGB sample dataset by integrating airborne LiDAR data and tree species information. Then, the AGB of the GGP stands was estimated using the Sentinel-2 data and the gradient boosting decision tree (GBDT) algorithm. The results showed that the AGB sample dataset constructed using the proposed approach exhibited strong consistency with field-measured data (R² = 0.89). The GBDT-based AGB estimation model shows high accuracy, with an R² of 0.96 and a root mean square error (RMSE) of 560 g/m². Key variables such as tasseled cap greenness (TCG), red-edge normalized difference vegetation index (RENDVI), and visible-band difference vegetation index (VDVI) were identified as highly important. This highlights that vegetation indices and tasseled cap transformation index information are key factors in estimating AGB. The AGB of major tree species in the new round of the GGP stands in Inner Mongolia ranged from 120 to 9253 g/m², with mean values of 978 g/m² for poplar, 622 g/m² for Mongolian Scots pine, and 313 g/m² for Chinese red pine species. This study offers a practical method for AGB estimation in GGP stands, contributing significantly to sustainable forest management and ecological conservation efforts. Full article

The gullied Loess Plateau, a region characterized by the overlapping of ecological fragility and energy abundance in China, requires urgent analysis of its territorial spatial conflict mechanisms to harmonize human–environment relationships. This study integrated multi-temporal remote sensing data (1990–2020) to develop a Comprehensive Spatial Conflict Index (CSCI) and applied the Optimal Parameter-based Geographical Detector (OPGD) to unravel the driving mechanisms of territorial spatial evolution in Qingyang City, Gansu Province. The results revealed that: (1) Territorial spaces exhibit a transition pattern of ecological restoration, urban expansion, and agricultural contraction. Forest and grassland ecological spaces increased by 1.42 percentage points (to 13.14%) and 1.26 percentage points (to 49.29%), respectively, while industrial-mining production spaces expanded sevenfold (0.01% to 0.08%), and agricultural production spaces decreased by 3.36 percentage points. (2) Spatial conflicts transitioned through three phases: ① A low-intensity stabilization phase (1990–2000), with 90.55% of areas under weak and moderately weak conflict (CSCI ≤ 0.4); ② A moderate conflict contraction phase (2000–2010), where weak conflict zones surged by 28.18 percentage points (13.06% → 41.24%), with moderate and moderately weak spatial conflict (0.2–0.6) decreasing by 28.27 percentage points (86.06% → 57.79%); ③ A moderately strong to strong expansion phase (2010–2020), with moderate and moderately strong conflict areas rising to 16.82%. Strong conflict zones (CSCI ≥ 0.8) expanded to 0.61%, spatially clustered in the Xifeng urban area and the Malian–Pu River corridor, showing significant positive correlations with gully density (>3.5 km∙km⁻²) and nighttime light index (NL). (3) The interaction between NDVI and land use intensity (LUI) dominated conflict patterns (q = 0.2583). In northern energy development zones (Huanxian County), LUI and precipitation (PRE) synergistically intensified landslide risks, while facility agriculture in central plateau farmlands (Ningxian County) triggered groundwater overexploitation. The coupling of road density (RND) and population (POP) factors (q = 0.1892) formed a transportation–population axial belt compression. Policy interventions exhibited spatial heterogeneity: the Grain-for-Green Program increased weak conflict zones by 28.18 percentage points, whereas wind power development in the Huanxian–Huachi northern belt escalated moderately strong to strong conflict zones by 3.6 percentage points. A three-dimensional governance framework integrating geomorphological adaptation, development phasing, and ecological compensation is proposed to optimize territorial spatial planning in the gullied Loess Plateau. Full article

Within the context of global desertification trends in arid regions, advancing afforestation and sand stabilization efforts are not only vital for human survival but are also key considerations in addressing the challenges of climate change and achieving sustainable development. This study, set against the backdrop of China’s new round of Grain-for-Green compensation policies implemented in 2014, investigates farmers’ behavior in planting economically valuable forests and grasslands driven by compensation incentives. Grounded in the principles of behavioral economics and assuming farmers as rational “economic agents”, this study focuses on farmers residing on the northern and southern slopes of the Tianshan Mountains in Xinjiang. Employing the fuzzy-set qualitative comparative analysis (fsQCA) approach, it examines the intricate causal mechanisms that shape farmers’ involvement or lack thereof in economic forest and grassland activities. These mechanisms are analyzed through the lenses of resource endowment, psychological perception, and external environmental factors. The results indicate that perceived benefits and neighbor imitation serve as essential conditions for non-participation in planting economic forests and grasslands. Three configurational pathways account for participation: farmers motivated by perceived benefits, those guided by the combined influence of “psychological perception and external environment”, and individuals driven by ecological aspirations alongside neighbor imitation. Additionally, four configurational pathways explain non-participation, with two types of farmers identified: those facing a dual deficiency of psychological perception and external environment, and non-high income traditional farmers dependent on agricultural irrigation water. Full article

Hexokinases (HXKs) in plants are multifunctional enzymes that not only phosphorylate hexose but also function as glucose sensors, integrating nutrient, light, and hormone signaling networks to regulate cell metabolism and signaling pathways, thereby controlling growth and development in response to environmental changes. To date, limited information is available regarding the HXKs of foxtail millet (Setaria italica L.). In this study, six HXK genes were identified and characterized in foxtail millet. Phylogenetic analysis revealed that the foxtail millet hexokinases were classified into three subfamilies, corresponding to the two types (B-type and C-type) of hexokinases in plants. Gene structure and conserved motif analysis showed that the SiHXKs exhibited varying numbers of introns and exons, with proteins in each subfamily showing similar motif organization. Evolutionary divergence analysis indicated that the foxtail millet HXK and green foxtail HXK genes families underwent both positive and negative selection and experienced a large-scale duplication event approximately 1.18–154.84 million years ago. Expression analysis revealed that these genes are widely expressed in roots, stems, leaves, panicles, anthers, and seeds, with most genes showing significantly increased expression in roots under abiotic stress conditions, including 20% PEG 6000 (drought stress), 200 μmol/L NaCl (salt stress), and 1 μmol/L BR (brassinosteroid-mediated stress response). These results suggest that these genes may play a pivotal role in enhancing stress tolerance. Subcellular localization assay showed that SiHXK5 and SiHXK6 were predominantly localized in mitochondria. Haplotype analysis revealed that SiHXK3-H1 was associated with higher plant height and grain yield. These findings provide valuable insights into the functional characteristics of HXK genes, especially in the context of marker-assisted selection and the pyramiding of advantageous haplotypes in foxtail millet breeding programs. Full article

Soil microorganisms play pivotal roles in terrestrial ecological processes. However, how soil microbial biomass and community characteristics respond to changes in land utilization in karst regions remains largely unknown. The present study investigated the impacts of land-use change on soil chemical properties, microbial community structure, and biomass in a karst region of southwest China across four land-use types: shrubland (natural vegetation restoration), plantation forest (managed vegetation restoration), orchards, and croplands. Vegetation restoration increased microbial biomass carbon and microbial biomass nitrogen. Shrubland had the highest bacterial and fungal abundance and fungal diversity; in addition, the soil microbial community structure differed significantly among land-use types. The dominant bacterial phyla were Actinobacteria, Proteobacteria, Acidobacteria, and Chloroflexi, whereas Ascomycota was the predominant fungal phylum, with its abundance declining significantly following vegetation restoration. Soil properties, including soil organic matter and available phosphorus, were strongly associated with microbial community composition and diversity in karst areas. The findings of this study are essential for gaining a deeper understanding of how changes in land-use affect soil properties and microbial dynamics, and provide valuable insights for ecological restoration and agricultural management in karst regions. Full article

Improvements in vegetation coverage are driven by both resource endowment conditions and policy behaviors. To accurately reflect the vegetation restoration effect after ecological policies, this study used the potential realization model to calculate the potential realization degree of vegetation restoration on the Loess Plateau and to assess the vegetation restoration effect after the Grain for Green Program from 2000 to 2020. Then, the influencing factors were explored using the spatial Dubin model. The results reveal that (1) the EVI value of the Loess Plateau in northern Shaanxi increased from below 0.25 at the beginning of the study to approximately 0.35 by the end, indicating that the green territory of the Loess Plateau gradually expanded to the northwest over the study period, and that the east and west of the Loess Plateau are key areas of vegetation cover for further improvement; (2) compared to the traditional EVI indicator, the potential realization degree can more accurately evaluate the vegetation restoration effect driven by ecological policies; (3) policy intensity is positively correlated with the growth rate of the vegetation restoration potential realization degree by 0.183 and significant at 1% level, making it the primary factor influencing the effect of vegetation restoration. Additionally, annual average precipitation and annual sunshine percentage have significant spatial positive contributions to the improvement of vegetation restoration on the Loess Plateau. The study’s findings are expected to contribute to the development of a scientific basis for adjusting the vegetation restoration policy on the Loess Plateau and enhancing ecological restoration efforts. Full article