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Global grassland degradation has prompted professionals and practitioners to critically consider about the future of grassland resources. Restoration actions related to payment for ecosystem services (PES) have been proposed as a possible approach to balancing grassland sustainable development and ecosystem service supply. Since 2005, approximately one billion U.S. dollars have been invested in the Three-River Headwater Region (TRHR) of China to restore 5.69 × 106 ha of degraded grasslands via grassland cultivation and fencing. Unfortunately, few literature has drawn valid and generalizable conclusions regarding the economic performance of these PES programs. Therefore, field data from multiple sites were collected to evaluate the economic returns of restoration actions, returns on investments (ROI), and trade-offs among ecosystem services of cultivated and fenced grasslands over different restoration years in the TRHR. The results revealed that PES-related restoration efforts in the TRHR had yielded a net profit of $14.34 billion, with $13.20 billion from the alpine meadow, $0.74 billion from the alpine steppe and $0.40 billion from the temperate steppe. These substantial economic can be attributed to the combined effects of the surge in specific ecosystem services and the synergistic improvement of all ecosystem services. The ROI of supporting service accounted for the largest proportion of ROI in total ecosystem services and exhibited drastic fluctuations with restoration years, whereas the ROI of other services either increased gradually or remained stable across different restoration periods. The trade-offs in ecosystem services varied greatly with grassland type. We observed an increasing synchronization of ecosystem services over time in the fenced alpine steppe, cultivated alpine meadow, and cultivated temperate steppe; whereas a similar trend was not detected in other grasslands. Our research underscores the importance of incorporating herders' willingness, assessing restoration performance of grasslands and adopting more targeted and adaptive restoration actions in subsequent PES programs. • PES helped balance sustainable development and ecosystem conservation. • Multiple site data was collected to explore ecological returns of restoration actions. • Restoration actions with PES programs had yielded a net profit of $14.34 billion. • Gains were owed to surge of specific ecosystem services and synergy of all services. • Herders' willingness and more targeted actions should be considered in next steps. [ABSTRACT FROM AUTHOR]

• Soil total nitrogen and biodiversity were improved by restoration intervention. • The relationships of above- and belowground ecosystem services changed over time. • Economic profit of ecological restoration was insignificantly changed over time. A great number of ecological conservation and restoration projects have been implemented to prevent the deterioration of alpine grasslands on the Qinghai-Tibetan Plateau. However, few researches have documented the effects of ecological projects on the improvement of ecosystem services of alpine grasslands based on field investigations. In this study, 24 plots of alpine meadow along different succession times were investigated to estimate the impacts of ecological restoration on four key ecosystem services (i.e., soil organic carbon sequestration (SOCS), soil total nitrogen sequestration (STNS), biodiversity, and aboveground biomass) in the Glog Tibetan Autonomous Prefecture of Qinghai Province, China. The results showed that STNS and biodiversity of degraded alpine meadows were significantly improved through restoration actions, while SOCS and aboveground biomass didn't change. The relationships of above- and belowground ecosystem services changed over restoration time. Trade-offs between aboveground biomass and biodiversity, between aboveground biomass and SOCS at stage Ⅲ were significantly improved, in contrast to those at stage Ⅰ. Trade-off between STNS and biodiversity at stage Ⅱ was significantly increased, in contrast to those at stage Ⅰ. Economic profit of ecological restoration was insignificantly changed along restoration time. Our results suggested that human-induced restoration was a feasible approach to improve the ecological and economical values of "Black Beach" on the Qinghai-Tibetan Plateau, and further restoration actions and long-term research are required to enhance the ecosystem services of revegetated degraded meadow. [ABSTRACT FROM AUTHOR]

Abstract Nitrogen deposition is notable in China, even in the high altitude region of Qinghai-Tibet Plateau (QTP). To identify the effects of nitrogen deposition on soil nutrient and ecological stoichiometry of the QTP's alpine grasslands, we treated three major types of grasslands (alpine meadow, alpine steppe, and cultivated grassland) with 6 different nitrogen addition levels: 0, 8, 24, 40, 56, 72 kg N ha−1 yr−1 through the years of 2015 to 2016. We sampled the soils at two depths, 0–10 and 10–20 cm in the peak-growing season (July) of each year. Results showed that: (i) soil total carbon and phosphorus are relatively stable under nitrogen deposition. (ii) Soil total nitrogen increases under low nitrogen addition rates while decreases under higher rates, and soil available nitrogen increases under nitrogen deposition in surface soil while decreasing in deeper soil. (iii) C:N, C:P, N:P had no significant difference between different nitrogen addition levels while there were significant differences between the two years under nitrogen addition. We speculate that nitrogen addition could alter soil nutrient conditions but there were certain limit of soil nutrient under N deposition. Highlights • Soil total C and P are stable under N deposition. • Total N increase under low N addition rate while decrease under higher rate. • Available N increase under N deposition in surface soil while decrease in deep soil • Stoichiometry had no significant difference between N addition levels. [ABSTRACT FROM AUTHOR]

• Grassland cultivation and fencing promoted EMF of the degraded alpine steppe. • Plant community composition was more correlated with EMF than soil community composition. • Biotic and abiotic factors together could explain more EMF than biotic factors alone. Alpine steppe is one of the most important grassland ecosystems on Qinghai-Tibetan Plateau (QTP), which has been greatly degraded in past decades. However, few studies have paid attention to the ecosystem multifunctionality (EMF) of restored degraded alpine steppes. Four treatments of alpine steppes (degraded alpine steppes, cultivated alpine steppes, fenced alpine steppes and intact alpine steppes) were investigated to explore the effect of treatment, biotic (above- and belowground community composition) and abiotic factors (pH and soil moisture) on restoring nine ecosystem functions (above- and belowground plant biomass, plant nitrogen content, soil organic carbon, soil nitrogen, soil phosphorus, soil microbial biomass carbon, microbial biomass nitrogen and microbial biomass phosphorus) and EMF of alpine steppe ecosystem in Madoi County of Qinghai Province, China. Our results showed that both grassland cultivation and fencing significantly promoted EMF of the degraded alpine steppes. Aboveground plant community composition was more significantly correlated with EMF of the alpine steppes than belowground soil community composition in the process of ecological restoration. Combining abiotic factors with biotic factors could improve the ability to explain EMF than biotic factors alone. Overall, aboveground community composition and soil moisture played determining roles in restoring EMF of alpine steppes. [ABSTRACT FROM AUTHOR]

China has recently implemented the latest rural land tenure reform with the "Separating Three Property Rights" as non-tradable land ownership, non-tradable land contracting right and tradable land use right, leading to a dramatic change in grassland management strategies in vast pastoral areas. However, the impact of this new reform on grassland management practices is widely debated by scholars and policy analysts. To identify the factors impacting the pastoralists' choice of grassland management practice and the social, economic and ecological benefits derived from different grassland management practices, we conducted a field survey of pastoralists (n = 259) in 7 counties on the Qinghai-Tibetan Plateau. The results showed that respondents' gender, grassland area, scale and location of the village, grassland condition perception significantly exerted positive influence on pastoralists' willingness to participate in cooperative grassland management practices, while grassland fence and urban life expectation negatively influenced the willingness. We found that cooperative grassland management practices led to significantly higher household incomes, more equal gender relationships and better-managed grasslands than individual ones. In spite of this, there were still a large number of pastoralists who chose individual grassland management practices due to their long-term customary operations. In conclusion, this new rural land tenure reform has facilitated pastoralists' choice for diverse grassland management practices and the promoted voluntary large-scale cooperative grassland management practices benefit the social-ecological system of pastoralism. • Land tenure reform promotes the free choice of grassland management practices. • Most pastoralists adhere to the individual grassland management practices. • Cooperative management practices benefit the social-ecological system. [ABSTRACT FROM AUTHOR]

• It was found that the agricultural land expanded significantly, desert reduced from 1993 to 2019 in the oasis region in Hotan River Basin, China. • The key indicators of the coupling system of vegetation–climate, soil-adjusted vegetation index, albedo, surface temperature, and evapotranspiration were calculated and mapped their spatial-temporal dynamics. • We investigated how the different landscape patterns altered the interaction between vegetation and climate in the desert oasis ecosystem and quantified the effects with structural equation model. In the arid region, the oasis is characterized by a desert substance and a mosaic of vegetation. The biophysical processes and interactions between vegetation and the local climate in this kind of region are determined by the macroscopic structure of the ecosystems, i.e. landscape patterns. To understand how these landscape patterns impact regional hydro-heat coupling across space and evolve over time, we utilized remote sensing observational data and methods to examine the relationships among these factors. In this case, we focused on the oasis along the upstream of the Hotan River Basin in the Taklamakan Desert in Xinjiang of western China and employed the satellite imagery datasets of Landsat from 1993 to 2019 to investigate the dynamics of vegetation–climate factors. Based on the land use and cover change datasets, the landscape pattern metrics, including patch density (PD), contagion index (CONTAG), fractal dimension (FRAC), were calculated to measure the landscape features on the different aspects, i.e. the fragmentation, the connectivity, and the complexity. With the algorithm of land surface energy balance, the land surface indicators, including the soil-adjusted vegetation index (SAV I), albedo, surface irradiance temperature (T s), and evapotranspiration (ET), were calculated to represent the key process in the interaction of vegetation–climate. The temporal-spatial dynamics of the landscape patterns and the vegetation–climate metrics were mapped and demonstrated in a quantitative manner. The statistical results revealed that during the past decades, the agricultural land in the study area had significantly increased by 17 %. Grassland and shrubs had also expanded, while the desert area decreased from 82.57 % to 78.82 % of the total area, with an overall reduction rate of 1.4 %/10a. It was found the study area was getting warmer and dryer based on the general trends of T s and ET observed during the period of 1993–2019. The agricultural land had the highest PD and CONTAG , and the lowest FRAC. The agricultural land had the lowest T s and the highest ET. The results of structural equation model identified the decoupling effects of PD and CONTAG on the regional hydro-heat environment, while confirmed that FRAC had positive impact on the coupling between T s and ET. Our study bridged the landscape pattern with the regional vegetation–climate interaction and provided the suggestions for the landscape planning and management for a more sustainable arid region. [Display omitted] [ABSTRACT FROM AUTHOR]

Highlights • An evaluation system considering pressure and pressure-bearing was established. • Grid scale ecological security was evaluated using this system and entropy method. • County scale security level was evaluated based on entropy matter-element model. • Changes of ecological security situation between 2000 and 2015 were explored. Abstract Ecological security is important for social and economic sustainable development which needs stable resources and eco-environment support. In this study, we established an evaluation indicator system considering pressure and pressure-bearing to quantify the ecological security for Kunming city as it is a socioeconomic center in Southwest China with important ecological niche and rapid urbanization. According to the weights assigned by entropy method, we overlaid 13 indicators which were divided into 2 units, pressure indicators and pressure-bearing indicators, to evaluate the ecological security on grid scale. And then, ecological security level on district-county scale was evaluated based on the entropy matter-element model. On this basis, we explored their spatial distribution characteristics and the change trend from 2000 to 2015. Results showed that spatial distribution characteristic of ecological security evaluation was similar with the results of pressure evaluation, showing the scores and levels gradually increased from the urban area to the surrounding areas. Compared the ecological security levels in 2000 and in 2015, both of the highest value and the lowest value increased slightly. In general, the area with improved ecological security situation accounted for 89.10% of the total area. In terms of the change trend of ecological security levels, eight counties deteriorated while five counties remained unchanged which were driven by different deterioration reasons. The evaluation results of this study can provide comprehensive and targeted support for regional sustainable development. [ABSTRACT FROM AUTHOR]

Partitioning, a method considering environmental protection and development potential, is an effective way to provide regional management strategies to maintain ecological sustainability. In this study, we provide a large-scale regional division approach and present a strategy for Southwest China, which also has extremely high development potential because of the “Western development” policy. Based on the superposition of 15 factors, including species diversity, pattern restriction, agricultural potential, accessibility, urbanization potential, and topographical limitations, the environmental value and development benefit in the region were quantified spatially by weighting the sum of indicators within environmental and development categories. By comparing the scores with their respective median values, the study area was divided into four different strategy zones: Conserve zones (34.94%), Construction zones (32.95%), Conflict zones (16.96%), and Low-tension zones (15.16%). The Conflict zones in which environmental value and development benefit were both higher than the respective medians were separated further into the following 5 levels: Extreme conflict (36.20%), Serious conflict (28.07%), Moderate conflict (12.28%), Minor conflict (6.55%), and Slight conflict (16.91%). We found that 9.04% of nature reserves were in Conflict zones, and thus should be given more attention. This study provides a simple and feasible method for regional partitioning, as well as comprehensive support that weighs both the environmental value and development benefit for China's current Ecological Red Line and space planning and for regional management in similar situations. [ABSTRACT FROM AUTHOR]

Rapid plantation expansion and its associated impacts on habitat fragmentation and landscape connectivity in many tropical areas has raised increasing concerns as to its impact on Ecosystem Services (ES). Using the InVEST modelling suite, we evaluated critical ES dynamics in four zones of varying plantation expansion intensity (high, medium, low and no plantation expansion) in Xishuangbanna prefecture in Southwest China from 1976 to 2012. Based on these results, we also exmained the relationship between ES and landscape pattern and connectivity derived by the “probability of connectivity” model. We found that during the study period, plantation area increased more than 20 times in Xishuangbanna prefecture as a whole, while broad-leaved forest cover decreased by nearly 30%. The impact of plantation on ES was substantial at both the regional and local scale. Carbon stocks and water yield services decreased by 15.48% and 10.85%, respectively, from 1976 to 2012 throughout the region as a whole. Within the selected study zones, carbon stock and water yeild decreased by 45% and 32%, respectively, from the no plantation to the high plantation zones in 2012 specifically. Plantation expansion has also resulted in a decrease in natural forest cover and a high level of habitat fragmentation. Landscape connectivity decreased by a range of 54.64–95.58% throughout the study area, with 134.58 km 2 of forest patches of high importance reduced to medium or low importance during the study period. Correlation analysis showed that carbon storage was more closely correlated to landscape connectivity than forest habitat percentage, large patch index or cohesion index. Together, these results highlight that habitat configuration with a high connectivity level between fragmented patches is important for maintaining critical Ecosystem Services. [ABSTRACT FROM AUTHOR]

Tree species and afforestation age can affect soil carbon (C) and nitrogen (N) sequestration as well as soil properties through different litter input and microbial activities. However, uncertainty remains because the responses vary under different climates and prior land uses. A site-specific study was conducted to investigate the dissimilarities in plant litter, soil properties, and soil microbial biomass and their influencing factors of different aged (22, 32, and 44 years) larch (Larix principis-rupprechtii) plantations and different aged (19, 30, and 43 years) Mongolian pine (Pinus sylvestris var. mongolica) plantations. In general, afforestation increased soil organic carbon (SOC), soil total nitrogen (STN), soil microbial biomass carbon (MBC), and soil microbial biomass nitrogen (MBN) contents compared with those of sparse grassland. However, there was still room for improvement in these variables compared with local natural secondary forest, which was dominated by white birch (Betula platyphylla , a deciduous broad-leaved tree species). Changes in STN, SOC, MBC, and MBN contents with afforestation age were almost insignificant in larch plantations, while significant increase can be found in STN (only in 10–20 cm soil layer), MBC and MBN in Mongolian pine plantations. The results indicated that larch was superior to Mongolian pine in soil C and N sequestration and soil fertility improvement at an early afforestation stage probably because of the higher C and N inputs from litter and higher N supply in the soil. There is an upper limit of carbon and nitrogen sequestration and soil fertility in the coniferous plantation, and mix planting of broad-leaved trees in coniferous forests may make up for this disadvantage. This study provided a reference for the selection of afforestation tree species in northern China and other areas with similar climatic conditions. • Afforestation increased SOC, STN, MBC, and MBN contents compared with those of barren land. • Changes in STN, SOC, MBC, and MBN contents with afforestation age varied in larch and Mongolian pine. • Larch was superior to Mongolian pine in soil fertility improvement at an early afforestation stage. • The higher C and N inputs from litter and N supply form soil may cause the differences between larch and Mongolian pine. [ABSTRACT FROM AUTHOR]

Exposure to air pollutants is a significant trigger of asthma in China. However, there is little evidence of which pollutants are associated most with asthma at the national level, and little research on pollutants' critical values based on concentration-response (C-R) curves. Further, the potential influential variables of air pollutants have not been identified clearly. In this study, logistic regression analyses were used to evaluate the associations between air pollutants and asthma based on 14176 samples across 12 provinces in China in 2015. We also fit a generalized additive model to evaluate the nonlinear C-R curves to identify the critical values. Our results showed that PM 10-2.5 (odds ratios, 95% confidence intervals: 0.95, 0.90–1.00) and NO X (odds ratios, 95% confidence intervals: 0.98, 0.96–1.00) were associated significantly with asthma's prevalence (p < 0.05) in China, in which the correlation between NO X pollution and asthma's prevalence was relatively more significant. The risk of asthma increased significantly when the average annual PM 10-2.5 and NO X concentrations exceeded approximately 40 μg/m3 and 67 μg/m3, respectively. The results of structural equation modelling confirmed that economic scale was the most important driving force for PM 10-2.5 and NO X pollution. Economic scale primarily had a direct influence on increased PM 10-2.5 concentrations, while it primarily had an indirect influence on increased NO X concentrations. Our findings contribute to the limited evidence on PM 10-2.5 and NO X pollution's effects on asthma's prevalence in China. • PM 10-2.5 and NO X were associated significantly with prevalence of asthma in China. • The critical value of PM 10-2.5 concentrations for asthma was 40 μg/m3 in China. • The critical value of NO X concentrations for asthma was 67 μg/m3 in China. • Economic scale had the strongest impact on PM 10-2.5 and NO X pollution. [ABSTRACT FROM AUTHOR]