Anthropogenic pollution discharges, hotspot pollutants and targeted strategies for urban and rural areas in the context of population migration: Numerical modeling of the Minjiang River basin

Unprecedented urbanization-induced population migration in China severely affects the scale and geographic distribution of anthropogenic pollutant discharge. Understanding how pollutant discharge patterns respond to population migration can help guide future efforts to maintain water sustainability. Here, based on a new calculation framework with 18 dynamic parameters designed for anthropogenic discharges, we finely tracked and visualized the effects of population migration on the spatial and temporal changes in anthropogenic discharge from 1980 to 2019 in the Minjiang River basin. The results indicate that the increasing effect of population migration on anthropogenic discharges peaked in 2002 and started to contribute to pollutant reduction from 2010 onward. The direct impact of population migration only contributes to the shift of anthropogenic discharges from rural to urban areas, while the migration bonus is the key factor leading to the reduction in anthropogenic discharges. Population migration is highly beneficial for chemical oxygen demand (COD) reduction, which has contributed to a shift from COD to NH₄⁺-N and total phosphorus (TP) as hotspot pollutants in the whole basin (NH₄⁺-N in urban areas and TP in rural areas). Moreover, pollution reduction resulting from the demographic bonus phenomenon has remained limited only to urban areas. Since approximately 2010, the per capita amount and total amount of anthropogenic pollutant discharges in rural areas have exceeded those in urban areas; in particular, the per capita COD and TP discharges in rural areas reached four times those in urban areas. This suggests that future pollution control strategies should give more attention to rural areas and focus on the differentiation and targeting of urban and rural areas.

Non-linear effects of natural and anthropogenic drivers on ecosystem services: Integrating thresholds into conservation planning

Ecosystem services (ESs) have been widely used for ecological protection and land spatial planning. Natural and anthropogenic drivers exhibit a strong dynamic coupling relationship with ESs. However, current ESs-related research focused on mapping the ESs spatially or investing the trade-offs and synergies relationship between ES, ignoring the nonlinear response of ESs to natural and anthropogenic drivers. Here we aimed to investigate the nonlinear effect of 14 potential drivers (8 natural and 6 anthropogenic) on the total value of six typical ESs (ESV). Taking Beijing-Tianjin-Hebei urban agglomeration (BTH) in China as an example, we established 14 constrain lines and identified critical thresholds through the restricted cubic splines (RCS) regression. We found strong non-linear impacts of natural and anthropogenic drivers on ESV and critical thresholds existed among all the 14 constrain lines. The RCS plots showed that the overall ESV was kept at a high level before or after certain thresholds (e.g., altitude >687 m, slope >13.4°, NDVI >0.7, distance from water <31.2 km, etc.). We categorized these threshold combinations and found the potentially high ES delivery areas were mainly distributed in the Yanshan Mountian, accounting for approximately 5% of the total BTH region. These critical thresholds offer a new method to delineate conservation and restoration priority areas.

Impacts of China’s Western Development and Protection Strategy: An Ecosystem Services Perspective of Western China

Policies directly affect land-use change, which in turn, affects ecosystem services. In parallel with the implementation of a full-scale development program for the western region, the Chinese government has introduced a series of ecological protection and restoration strategies for development and construction. This study conducted a quantitative spatial evaluation of the ecosystem service value (ESV) of national nature reserves in the western region under this dual policy of development and protection. On the basis of land-use data and related evaluation parameters, fluctuations in the valuation of ecosystem services during 2000–2010 were analyzed in response to land-use changes under the comprehensive policy. Results showed that the increases in the areas of forestland and water bodies led to an increase of CNY 74.1 billion in the ESV from 2000 to 2010, equivalent to 2.02%. Grassland with increased production capacity and water bodies were the main factors driving the total ESV dynamics. Values of all ES increased significantly. Therefore, the ecological conservation and restoration policy, along with the development policy, had a positive influence on ecosystem services in the nature reserves in western China.

Challenges and Opportunities in Aligning Conservation with Development in China's National Parks: A Narrative Literature Review

As part of its effort to balance economic development with environmental objectives, China has established a new national park system, with the first five locations formally established in 2021. However, as the new parks all host or are proximate to human populations, aligning the socioeconomic needs and aspirations of local communities with conservation aims is critical for the long-term success of the parks. In this narrative review, the authors identify the ecological priorities and socioeconomic stakeholders of each of the five national parks; explore the tensions and synergies between these priorities and stakeholders; and synthesize the policy recommendations most frequently cited in the literature. A total of 119 studies were reviewed. Aligning traditional livelihoods with conservation, limiting road construction, promoting education and environmental awareness, and supporting the development of a sustainable tourism industry are identified as important steps to balance conservation with economic development in the new national parks.

Accelerating the Improvement of Human Well-Being in China through Economic Growth and Policy Adjustment

Human well-being in many countries lags behind the gross domestic product (GDP) due to the rapid changes in the socio-economic environment that have occurred for decades. However, the mechanisms behind this complex phenomenon are still unclear. This study revealed the changes in human well-being in China from 1995 to 2017 by revising the genuine progress indicator (GPI) at the national level and further quantified the contribution of interfering factors that have driven the increase in the GPI. The results indicated that: (1) The per capita GPI of China showed an increasing trend with an annual growth rate of 12.43%. The changes in the GPI followed the same pattern as economic development, rather than presenting the phenomenon of economic growth combined with a decline in welfare that has been recorded in some countries and regions. (2) The increase in human well-being was mainly driven by economic growth, but it was most sensitive to social factors. (3) Increasing income inequality and the cost of lost leisure time contributed obvious negative impacts (24.69% and 23.35%, respectively) to the per capita GPI. However, the increase in personal consumption expenditures, the value of domestic labor, ecosystem service value, and net capital growth accelerated the rise in the GPI, with positive contribution rates of 30.69%, 23%, 20.54%, and 20.02%, respectively. (4) The continuous increase in economic investment and the strengthening of social management due to policy adjustments completely counteracted the negative impacts on human well-being, thus leading to a great increase in the per capita GPI. Such insights could provide theoretical support for decision making and policy implementation to improve global human well-being.

Endogenous Development Models and Paths Selection of Rural Revitalization from the Perspective of Ecological Environment Advantages: A Case Study of Nanshi Village, China

This article aims to discuss how to give full play to the comparative advantages of the rural ecological environment and realize the endogenous development of rural society and economy in China. First, based on the ecological economy theory of "lucid waters and lush mountains are golden and silver mountains" (the "two mountains" theory), we integrated the theories and methods of ecology, economics, and geography disciplines to examine the transformation of "ecological advantages" into "economic development" from a comprehensive perspective. Second, based on the matching relationship between the division of major function zones and the classification of ecological services, we creatively constructed a theoretical framework for the endogenous development of rural areas. Third, accounting indicators and methods for rural ecological products' biophysical quantity and monetary value are established. Finally, we conducted an empirical study of Nanshi Village in central China as a case. The results showed that: The benefits provided by ecosystems to the development of human society would be underestimated if it is measured only by the provisioning services; the per capita Gross Ecosystem Product (GEP) of the case area was three times the per capita disposable income of rural permanent residents in the same period. Taking advantage of the rural ecological environment to promote the actual transformation of the potential value of ecological products is the feasible path for rural revitalization. One of the implications of this study is that it links the rural ecological and environmental advantages with social and economic development from the perspective of ecological economics and provides decision-making support for this case and other similar rural ecological industry revitalization practices.

How Does Topography Affect the Value of Ecosystem Services? An Empirical Study from the Qihe Watershed

Topographic position indices (TPIs) measure essential impacts on ecosystem service supply capacity. The identification of changes in ecosystem services and value metrics under varying TPIs has become a topical subject of global change research. Multidimensional changes in spatiotemporal and geographical aspects of ecosystem service values (ESVs) are assessed in this article using land cover/use data from 2000-2015. Effects of land-use/cover changes and topographic indices on ESVs are explored using the Chinese terrestrial unit area ecosystem service value equivalence table combined with topographic factors. A sensitivity index is introduced to quantify the robustness of total ESV to land-use/cover and topographic indices. The results show that: (1) The total ESV in the Qihe watershed declined with a change in land-use/cover during the period 2000-2015. The maximum ESV was CNY 1.984 billion in 2005 and the minimum was CNY 1.940 billion in 2010; (2) The response of ESV to land/use cover varied greatly across TPIs, with the most significant change in ESV occurring in the 0.6-0.8 TPI range and the greatest change in a single ecosystem service occurred in water areas; (3) The sensitivity indices of ESVs are all less than 1. The sensitivity indices of unused land and water tended to zero. Woodland sensitivity indices were the highest at 0.53, followed by those of arable land and grassland, owing to the large proportion of arable land and grassland areas in the overall area of land-use categories.

Elevation dependency of ecosystem services supply efficiency in great lake watershed

Although it is well acknowledged that the improvement of ecosystem services is conducive to human well-being, there is still a lack of approach to determining reasonable improvement goals, especially for ecosystem services with trade-off relationship. Based on the method of production possibility frontier (PPF), this study presented a novel approach to identifying the improvement goals of interacting ecosystem services with considering their context dependency. By calculating the gap between the current supply of ecosystem services and the reasonable improvement goal, the ecosystem services supply efficiency was defined and measured to identify the optimization potentials of ecosystem services with trade-off relationship. The results showed that the supply efficiency of ecosystem services (grain production and water purification) decreased and then increased significantly along with the increasing of farmland area ratio in the Dongting Lake Basin (DLB). Meanwhile, the inflection point appeared when the farmland area ratio was 0.16. The change of farmland area ratio was significantly influenced by the change of elevation, with the regression coefficients of elevation on the left and right sides of the inflection point being -1.28 and -0.5 respectively, which were higher than that of other factors. Along with the increasing of elevation, the ecosystem services supply efficiency decreased but increased when the elevation exceeded 721.74 m. Furthermore, the sub-watersheds with farmland area ratio below the inflection point, i.e. mainly high elevation areas, were located around national or provincial level poor counties, posing a great challenge for improving ecosystem services with trade-off relationship. Development strategies for sub-watersheds should consider the non-linear trade-offs of ecosystem services, especially the opposite stages of supply efficiency. This study highlighted the elevation dependency of ecosystem services supply efficiency through farmland area ratio in great lake watershed.

Coordinating community resource use and conservation: An institutional diagnostic practice in the Wuyishan National Park

Maintaining community resource use and securing ecosystem services for the public is a major issue in protected area management. This research developed an institutional diagnostic tool for community resource use based on the theories of "Common-Pool Resources", "Environment Entitlement" and "Socio-ecological System". This tool is maturing and tested in the Wuyishan National Park through a knowledge co-production process of communities' narratives and researchers' observations. It was used to identify key institutional factors that affect communities' ecosystem management, facilitate a negotiation procedure that can motivate communities' acceptance of new rules and participation in conservation, and provide policy entry points for sustaining both the ecosystem and rural livelihoods. Results show that key factors affecting resource accessibility mainly include land policy at the macro scale, protected area planning and management at the meso-scale, and the internalising of modern regulations and technologies with historical inheritance at the micro-scale. Key institutions affecting access to ecosystem services and well-being include mainly the formal institutions such as the market and credit system at the meso-scale, and informal institutions expressed by collective actions at the micro-scale. Results also indicate that local people mainly cared about the procedural legitimacy and their environmental autonomy for negotiation in the multi-stakeholder context. They required a reasonable and clear definition of resource use regulation, and low risks to join in a negotiation. By integrating the key institutions and negotiation demands, we provided the policy entry point to facilitate the institutional change in Wuyishan National Park. This diagnostic tool is proved applicable in the way of knowledge co-production, and it is promising to help formulate context-specific conservation policies to facilitate the community to participate in the construction and management of protected areas for win-win outcomes of the natural ecosystem and community welfare.

Hidden challenges behind ecosystem services improvement claims

Substantial evidence indicates that China’s afforestation statistically contributed to the ecosystem services (ES) improvement. However, we found the potential challenges behind this improvement, especially in water-limited areas. We propose an attribution analysis method, which can assess the specific contribution of natural, human and cognition degree drivers to ES dynamics. The results found that the ratio of natural and human drivers in the area north of China’s 400 mm precipitation isopleth is 2:7. This means local vegetation capacity has already exceeded water limitation, implying a conflict between nature and humans. However, the natural contribution in the area between 400 and 800 mm precipitation isopleth is negative, whereas the human contribution is 91%. This means this area has fragile natural conditions and needs more flexible policies. The ratio of natural and human drivers in the region south of 800 mm precipitation isopleth is 6:3, suggesting the ecological policies here can be maintained.

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PDE is used to assess the contribution of natural and human drivers to ES changes

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Land use management dominantly contributed (55%) to China’s ES improvement

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Re-vegetation in the area north of 400 mm precipitation isohyet exceeded NPP threshold

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The area between 400 and 800 mm isoprecipitation line is the key area with ES decrease

Coupling coordination analysis and spatiotemporal heterogeneity between sustainable development and ecosystem services in Shanxi Province, China

Excessive human activities destroy the structure and function of ecosystem and threaten sustainable development. As a typical resource-based area, Shanxi Province is facing an increasingly serious contradiction between ecosystem and sustainable development, with the overexploitation of resources. In view of this, the coupling coordination degree model was used to measure the association between sustainable development and ecosystem services (SDESs), and geographically and temporally weighted regression model was used to explore the correlation between SDESs and measure the correlation between ecosystem services (ESs) and sustainable development at the county level from 2000 to 2015 in Shanxi Province. The results showed an increase in the sustainable development level and all ESs except soil retention. The coupling coordination degree (CCD) of soil retention and sustainable development decreased, while other services increased. Habitat quality had the strongest negative correlation with sustainable development. There were obvious spatiotemporal heterogeneities in the CCD and correlation of SDESs, which is helpful for promoting regional sustainable development and optimize ecosystem decision-making.

Payments for Watershed Ecosystem Services in the Eyes of the Public, China

Recent decades have witnessed an increased development of schemes for payment for watershed ecosystem services (PWES). However, the public is usually excluded from PWES systems. Reliable and empirical research on PWES from the public perspective is scarce. Aiming to understand public perceptions, attitudes, participation, and responses to PWES, this paper investigated local residents living in the Yongding River watershed area through a face-to-face questionnaire survey. The results showed that the public had limited knowledge of PWES. The public was keen to be involved in PWES decision-making, but the current level of public participation was very low. Regarding willingness to pay (WTP) and willingness to accept (WTA), nearly 55% of the respondents supported paying the upstream residents for protecting the environment if they were beneficiaries in the downstream areas, while 85% of the respondents agreed to accept compensation if they were contributors to environmental improvement in the upstream areas. Although some of the respondents’ daily lives were affected by the watershed environment, they were reluctant to pay, reflecting a sign of “free-riding”. The regression analysis showed that public concerns, values, knowledge of PWES and the watershed environment, and demographic factors determined the WTP and WTA. The results of the contingent valuation method and opportunity costs method showed that the annual payment for headwater conservation areas (Huailai and Yanqing) ranged from CNY 245 to 718 million (USD 36 to 106 million). This study contributes to our limited knowledge and understanding of public sentiment and makes recommendations for improving public receptivity to PWES.

Spatiotemporal patterns of gross ecosystem product across China's cropland ecosystems over the past two decades

As the largest artificial ecosystem on Earth, croplands not only secure the basic living materials for people but also provide ecological service values for human society. For croplands, ecosystem services have proven to be of great value and are closely linked to human activities and climate change. However, spatiotemporal patterns of cropland ecosystem services and their drivers still need to be further assessed quantitatively. In this study, we provided a comprehensive evaluation of ecosystem services across China's cropland ecosystems over the past two decades using gross ecosystem product (GEP) as a single metric of the monetary evaluation of final ecosystem services. The values of material services, regulating services, and cultural services were calculated to summarize the GEP value of cropland ecosystems in China. Our results showed that the multiyear mean value of GEP was 4.35 × 107 million CNY. The value of regulating services reached 3.86 × 107 million CNY, followed by material services of 4.76 × 106 million CNY and cultural services of 1.16 × 105 million CNY. GEP value was different among provinces, leading to a heterogeneous spatial pattern associated with population and cultivated area. Moreover, we analyzed the trends in the GEP value at the provincial and national scales. The results showed that the GEP value of China's cropland ecosystems has increased over the period. The values of the material, regulating, and cultural services have increased at a rate of (0.35 ± 0.01) × 106 million CNY a−1, (1.12 ± 0.10) × 106 million CNY a−1, and (0.002 ± 0.0002) × 106 million CNY a−1, respectively (P &lt; 0.05). The majority of provinces had an increasing trend in GEP, yet some developed provinces, e.g., Beijing and Shanghai, showed a decreasing trend. Furthermore, we evaluated the impacts of social-economic and natural factors on changes in GEP. We found that rising prices for agricultural products and services boosted an increase in GEP. Meanwhile, the spatiotemporal patterns of GEP were also associated with the adjustments of planting area in each province. Overall, our findings highlight the importance of assessing spatiotemporal patterns of cropland ecosystem services for decision-makers.

Combined effects of multi-land use decisions and climate change on water-related ecosystem services in Northeast China

Land use intensification and climate change have resulted in substantial changes in the provision of ecosystem services, particularly in China that experienced sharp increases in population growth and demands for goods and energy. To protect the environment and restore the degraded ecosystems, the Chinese government has implemented multiple national ecological restoration projects. Yet, the combined effects of climate change and land use and land cover change (LULCC) over large spatial scales that brace multiple land use decisions and great environmental heterogeneity remain unclear. We assessed the combined effects of LULCC and climate change on water-related ecosystem services (water provision and soil conservation services) from 1990s to 2020s in Northeast China using the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model. We found that water yield decreased by 9.78% and soil retention increased by 30.51% over the past 30 years. LULCC and climate change exerted negative effects on water yield whereas they both enhanced soil retention; LULCC interacted with climate change to have relatively small inhibitory effects on water yield and large facilitation effects on soil retention. Changes in water yield were mainly attributed to climate change, while soil retention was largely influenced by LULCC and its interaction with climate change. Our research highlights the importance of land use decisions and its interactive effects with climate change on ecosystem services in a heavily disturbed temperate region, and provides important information to inform future land management and policy making for sustaining diverse ecosystem services and ensuring human wellbeing.

Land use trade-offs in China's protected areas from the perspective of accounting values of ecosystem services

"Accounting values" (quantity * unit value), assessed with an assumption of a constant unit value, are often used in creating macroeconomic aggregates like Gross Domestic Product (GDP). This approach has also been used to estimate the total value of ecosystem services (ES) - the benefits humans receive from functioning ecosystems. In China, this has been referred to as Gross Ecosystem Product (GEP). While the concepts of value and ES may be understood from multiple perspectives, ESs' accounting values contribute important information to the discussion of land use trade-offs in China's protected areas (PAs). These trade-offs include (1) whether additional conserved lands should be opened to tourism development, since tourism brings both positive and negative impacts; (2) whether PAs should be reduced, maintained, or expanded, since PAs safeguard sustainable wellbeing but also require maintenance; and (3) how to undertake conservation on lands traditionally used for human livelihood development, since conservation and livelihood may conflict. Previous studies have suggested (1) joint evaluation based on both GDP and ESs' values may lead to more sustainable decision-making than solely GDP-oriented evaluation; (2) the benefits of maintaining terrestrial PAs in China is $2.64 trillion/yr, over 14 times greater than the costs; (3) integrating ES valuation into environmental impact assessment helps link environmental impacts with human wellbeing and financial costs (e.g., land encroachment of a tourism highway in the Wulingyaun Scenic Area was estimated to cause permanent loss of ES values at $0.5 million/yr); and (4) integrating non-marketable cultural ESs into payment for ESs schemes can further balance conservation with livelihood development. Future research should consider (1) option and non-use values to present a more comprehensive picture of PAs' contributions to sustainable wellbeing and human interdependence with the rest of nature (2) both PAs' quantity (e.g., optimal coverage of PAs); and quality (e.g., management effectiveness, connectivity); (3) more sophisticated and feasible valuation methods (e.g., more cost-effective and engaged deliberation) to improve the credibility of aggregate values over large spatial scales; and (4) interaction between environmental components and ESs.

Measuring Gross Ecosystem Product (GEP) in Guangxi, China, from 2005 to 2020

The economic and social development evaluation system with the Gross Domestic Product (GDP) as the leading indicator is no longer applicable to the current social progress in China. It is essential to carry out an assessment of the Gross Ecosystem Product (GEP) to integrate ecological benefits into the economic and social evaluation system and promote sustainable socio-economic development. This study took Guangxi, an important province in South China, as the study area. We used four periods of land use and land cover data (LULC), meteorological data, soil data and yearbook statistics to construct a GEP assessment framework based on geographic information system (GIS) and remote sensing (RS) technologies. We accounted for the provisioning services, regulating services, and tourism services provided by Guangxi in 2005, 2010, 2015, and 2020 and analyzed the region’s and municipalities’ spatial–temporal pattern characteristics and trends of change in GEP. In addition, this study also discusses the relationship between GEP and GDP. The results showed that many important products and services provided by natural ecosystems in Guangxi had enormous economic benefits. GEP had increased from CNY 15,657.37 billion in 2005 to CNY 36,677.04 billion in 2020, and the distribution of GEP showed obvious spatial heterogeneity. The value of ecosystem regulation services was about 65–89% of GEP, which is the main component of GEP. From 2005 to 2020, natural ecosystem protection and socio-economic development have achieved coordinated development in Guangxi. GEP and GDP showed upward trends in general. Although Guangxi is relatively backward in terms of economic development, the scientific quantification of the unrealized value of the services provided by the ecosystem through GEP accounting makes it possible to transform ecological advantages into economic advantages. It could help the local government and people to re-recognize the value of ecological resources and realize the beautiful vision of lucid waters and lush mountains as invaluable assets.

Analyzing the Spatiotemporal Vegetation Dynamics and Their Responses to Climate Change along the Ya’an–Linzhi Section of the Sichuan–Tibet Railway

Vegetation dynamics and their responses to climate change are of significant spatial and temporal heterogeneity. The Sichuan–Tibet Railway (STR) is a major construction project of the 14th Five-Year Plan for Economic and Social Development of the People’s Republic of China that is of great significance to promoting the social and economic development of Sichuan–Tibet areas. The planned railway line crosses areas with a complex geological condition and fragile ecological environment, where the regional vegetation dynamics are sensitive to climate change, topographic conditions and human activities. So, analyzing the vegetation variations in the complex vertical ecosystem and exploring their responses to hydrothermal factors are critical for providing technical support for the ecological program’s implementation along the route of the planned railway line. Based on MOD13Q1 Normalized Difference Vegetation Index (NDVI) data for the growing season (May to October) during 2001–2020, a Theil-Sen trend analysis, Mann–Kendall test, Hurst exponent analysis and partial correlation analysis were used to detect the vegetation dynamics, predict the vegetation sustainability, examine the relationship between vegetation change and hydrothermal factors, regionalize the driving forces for vegetation growth and explore the interannual variation pattern of driving factors. The growing season NDVI along the Ya’an–Linzhi section of the STR showed a marked rate of increase (0.0009/year) during the past 20 years, and the vegetation’s slight improvement areas accounted for the largest proportion (47.53%). Among the three hydrothermal parameters (temperature, precipitation and radiation), the correlation between vegetation growth and the temperature was the most significant, and the vegetation response to precipitation was the most immediate. The vegetation changes were affected by the combined impact of climatic and non-climatic factors, and the proportion of hydrothermal factors’ combined driving force slightly increased during the study period. Based on the Hurst exponent, the future vegetation sustainability of the area along the Ya’an–Linzhi section of the STR faces a risk of degradation, and more effective conservations should be implemented during the railway construction period to protect the regional ecological environment.

Land Use Land/Cover Change Reduces Woody Plant Diversity and Carbon Stocks in a Lowland Coastal Forest Ecosystem, Tanzania

The East-African lowland coastal forest (LCF) is one of Africa’s centres of species endemism, representing an important biodiversity hotspot. However, deforestation and forest degradation due to the high demand for fuelwood has reduced forest cover and diversity, with unknown consequences for associated terrestrial carbon stocks in this LCF system. Our study assessed spatio-temporal land use and land cover changes (LULC) in 1998, 2008, 2018 in the LCF ecosystem, Tanzania. In addition, we conducted a forest inventory survey and calculated associated carbon storage for this LCF ecosystem. Using methods of land use change evaluation plug-in in QGIS based on historical land use data, we modelled carbon stock trends post-2018 in associated LULC for the future 30 years. We found that agriculture and grassland combined increased substantially by 21.5% between the year 1998 and 2018 while forest cover declined by 29%. Furthermore, forest above-ground live biomass carbon (AGC) was 2.4 times higher in forest than in the bushland, 5.8 times in the agriculture with scattered settlement and 14.8 times higher than in the grassland. The estimated average soil organic carbon (SOC) was 76.03 ± 6.26 t/ha across the entire study area. Our study helps to identify land use impacts on ecosystem services, supporting decision-makers in future land-use planning.

Trends in Research on Forest Ecosystem Services in the Most Recent 20 Years: A Bibliometric Analysis

Forest resources and the flow of ecosystem services they provide play a key role in supporting national and regional economies, improving people’s lives, protecting biodiversity, and mitigating the impacts of climate change. Based on the ISI (Institute of Scientific Information) Web of Science (WoS) database, we used a bibliometric approach to analyze the research status, evolution process, and hotspots of forest ecosystem services (FES) from a compilation of 8797 documents published between 1997 and 2019. The results indicated that: (1) research on forest ecosystem services has developed rapidly over the past 23 years. Institutions in the United States and other developed countries have significantly contributed to undertake research on the topic of ecosystem services. (2) The 11 hotpot key focus areas of completed research were payments for ecosystem services, biodiversity conservation, forest governance, ecosystem approaches, climate change, nitrogen, ecosystem management, pollination, cities, ecological restoration, and policy. (3) The trade-off relationships among ecosystem services, ecosystem resilience and stability have become the research frontier in this field. (4) Future research on FES will likely focus on the formation and evolution mechanism of ecosystem services; the interaction, feedback and intrinsic connections of ecosystem services at different scales; analysis of the trade-offs and synergies; unified evaluation standards, evaluation systems, model construction and scenario analyses; in-depth studies of the internal correlation mechanism between forest ecosystem services and human wellbeing; and realization of cross-disciplinary and multi-method integration in sustainable forest management and decision-making.

A Review of Ecosystem Services Research Focusing on China against the Background of Urbanization

The change in landscape patterns caused by urbanization is one of the main reasons for the degradation of global ecosystem services. Reducing the negative impact of rapid urbanization on ecosystems and promoting the coordinated development of cities and ecosystems have become a hot topic around the world. Based on Web of Science Core Collection and CNKI database papers, this study conducts a bibliometric analysis of ecosystem services research against the background of global urbanization from 2000 to 2022. At the same time, the research hot spots, regional distribution, research trends, and research contents are summarized by taking China as the key research area. The results show that: (1) the research hot spots of ecosystem services against the background of urbanization are generally the same in China and the world. Both of them are based on landscape pattern or land use; the research scale is from macro to micro; and the research method is from static to dynamic. (2) From the perspective of ecosystem service types, the four types of ecosystem service have been studied in China and other parts of the world, but there are differences in the specific types, quantity, and regional distribution. (3) Whether in China or other regions of the world, the studies on the trade-offs of ecosystem services against the background of urbanization are mainly at medium and large scales. Finally, ecosystem service bundles research, systematic thinking, and the combination of ecosystem services and territorial spatial planning against the background of urbanization are pointed out as key aspects of future research.

The payment scheme for ecosystem services in the coastal city based on the ecosystem services value and current payment efficiency: a case study in Jimo of Qingdao city, China

The reasonable strategies of payment for ecosystem services (PES) play a key role in solving the contradiction between ecological protection and economic development in coastal cities. However, at present, the payment efficiency is relatively low and the determination method of PES is lack. Therefore, in this study, the Jimo district of Qingdao city in China, a typical coastal city, was selected as study area, and the equivalent factor method and marine ecological capital assessment method were used to obtain terrestrial and marine ecosystem services value (ESV) and its tempo-spatial variations from 2010 to 2018. Moreover, the payment efficiency of the sea area and 15 towns over 8 years was measured using the Super-efficient SBM-DEA model based on undesired output. ESV presented a clear reduction over 8 years. The marine ecosystem provided the main service value, and waste treatment, water regulation, and soil formation were the top 3 main functions in the land ecosystem. Regulating services provided the highest component among all functions. The high-value areas were mainly distributed in the northeast and northwest regions and the low-value areas were in the south-central regions. The average payment efficiency of the sea area and 15 towns over 8 years shown a stable trend at a low level. On the basis of the evaluation of ESV and efficiency, a new possible payment scheme including payment order and quota was proposed. The total quota of marine ecosystem was 5.226 billion RMB (88% of the total) and of terrestrial ecosystem was 0.713 billion RMB. Tian Heng, Jin Kou, Yi Fengdian, and Ling Shan are the first 4 priority towns, with compensation amounts of 0.205, 0.083, and 0.063 billion RMB respectively, while the last 3 towns are Tong Ji, Huan Xiu, and Chao Hai accounting for 6.02% of the total. The theoretical payment total quota was 5.939 billion RMB, and which accounted for a low proportion of local GDP. The study can provide some recommendations for making the reasonable and feasible payment schemes for ecosystem services in coastal city, and it is feasible in the practice of ecological environment protection and sustainable development.

The Grain for Green Project in Contiguous Poverty-Stricken Regions of China: A Nature-Based Solution

The Grain for Green Project (GGP) is one of many Nature-based Solutions (NbS), which aims to address the challenge of ecological restoration while providing livelihood security for farmers in poverty-dominated regions. Evaluating the success of such a project can prove difficult. Here, we choose the contiguous poverty-stricken regions (CPSR) of China to study the multiple benefits of the GGP in the context of NbS. We collect ecological-monitoring data, forest-resources data, and socioeconomic data and use them in a distributed method with relevant indicators, to evaluate the ecological benefits of the GGP. Additionally, the socioeconomic benefits are evaluated using questionnaire-based surveys. Our results showed that the ecological benefits of the GGP in the CPSR were 5.6 × 1011 RMB/a in 2017, with the proportion of each ecosystem’s services being 27.1% (water conservation), 21.1% (biodiversity conservation), 18.4% (purification of the atmospheric environment), 13.1% (soil conservation), 12.9% (carbon sequestration and oxygen release), 5.4% (forest protection), and 1.6% (nutrient accumulation). In terms of socioeconomic benefit, the GGP changed the production methods of farmers, which resulted in income growth, with an average increase of 5100 RMB/a per household. In the context of NbS, ecological conservation, and restoration, the accurate and systematic monitoring of the socioeconomic and ecological benefits will become more important for government decisions.

The Effects of the Ecological Conservation Redline in China: A Case Study in Anji County

The Ecological Conservation Redline (ECR) of China plays an important role in avoiding ecological space occupancy and maintaining regional ecological security. Anji County in Zhejiang Province is one of the first regions to implement the ECR in China. This paper takes Anji County as an example to analyze the effects of ECR. To do this, we first set up two scenarios with the CLUE-S model: a normal land-use development scenario (NLDS) and an ECR implementation scenario (ECRS); then we compare the land use of 2010 and 2015 under NLDS and ECRS. Land use, ecosystem services value (ESV), landscape metrics, and ecological product outputs were compared between the entire county and the ECR areas. The results revealed the following: (1) From 2000 to 2015, the ecological land in Anji County decreased by 4.03%, while it decreased by 1.17% in the ECR areas. (2) In the ECR areas, there was less arable land and construction land of the ECRS than in the NLDS, which indicates the ECR impeded the expansion of construction land and arable land in the ECR areas. (3) The ECR areas account for 39% of Anji County but contribute more than 80% to the ESV of the whole county. During 2000–2015, the ESV of the entire county decreased while the ESV of the ECR areas increased. (4) From 2000 to 2015, whereas landscape fragmentation of the entire county increased, that of ECR areas decreased. (5) Since the ECR’s implementation, Anji County has vigorously developed the bamboo industry, ecological agriculture, the tourism industry, and achieved rapid economic development via industrial restructuring and transformation. On the whole, the ECR has neither adversely affected land development nor economic development but instead has promoted the optimization of the land’s spatial development pattern.

Revealing the Coupling Relationship between the Gross Ecosystem Product and Economic Growth: A Case Study of Hubei Province

The question of how to balance rapid economic growth with ecosystem pressures has become a key issue in recent years. Using the Tapio decoupling model, the spatial autocorrelation model, and the LMDI decomposition model, we analyzed the spatiotemporal variation in gross ecosystem product (GEP) in Hubei Province, studied the relationship between GEP and economic growth, and analyzed the driving factors of GEP variation. The results show that, during the period 2010–2019, the decoupling coefficient between GEP and economic growth in Hubei Province gradually decreased, while the decoupling relationship changed from weak decoupling to strong decoupling; this change is reflected not only in the decoupling index values of various cities but also in the number of changing cities, so this negative change should attract the attention of policy-makers. In addition, there is a significant local spatial autocorrelation in Hubei Province, mainly distributed in the northwest and southwest of the province, and the trend is becoming increasingly obvious. As the decoupling trend is negative, it is necessary to pay attention to local autocorrelation changes, especially in highly correlated cities, and take action to prevent the further exacerbation of such decoupling to maintain healthy economic and social development. Regarding the driving factors of GEP changes in Hubei Province, cities with strong decoupling and those with weak decoupling have certain differences, and different types of decoupling cities need to adopt different strategies to alleviate pressure on the ecological environment. Cities with a weak decoupling need to address the problem of pollutant emissions associated with industrial upgrading and the positive impact of scientific and technological innovation on the ecological environment. Cities with strong decoupling should not only address pollutant discharge but also improve the area of ecological land. From the perspective of urban development, the high-quality development trend of Wuhan, Yichang, Xiantao, Qianjiang, Xianning, and other cities shows a continuous trend of improvement. Ezhou, Jingzhou, Shennongjia, and other cities need to guard against the loss of ecosystems caused by economic growth.

Dynamic Variation of Ecosystem Services Value under Land Use/Cover Change in the Black Soil Region of Northeastern China

A better understanding of the dynamic variation in the ecosystem service value (ESV) under land use/cover change (LUCC) is conductive to improving ecosystem services and environmental protection. The present study took Landsat TM/ETM remote sensing images and socio-economic statistic data as data sources and extracted land-use data using RS and GIS technology at 5-year intervals from 1990 to 2020. Then, we interpreted the spatio-temporal characteristics of LUCC and analyzed ESV changes using the value equivalence method in the black soil region of northeastern China (BSRNC). The main results showed that land use changed significantly during the study period. Cultivated land continued to expand, especially paddy areas, which increased by 1.72 × 10⁶ ha, with a relative change of 60.9% over 30 years. However, grassland decreased by 2.47 × 10⁶ ha, with a relative change of −60.6% over 30 years. The ESV showed a declining trend, which decreased by CNY 607.96 million during 1990–2020. The decline in forest and grassland caused a significant decline in the ESV. Furthermore, the ESV sensitivity coefficients were less than one for all of the different categories of ecosystem services. LUCC has a considerable impact on ESV in the BSRNC, resulting in ecosystem function degradation. As a result, future policies must emphasize the relationship between food security and environmental protection in situations of significant land-use change.

Spatial-temporal variations of terrestrial evapotranspiration across China from 2000 to 2019

Terrestrial evapotranspiration (ET) refers to a key process in the hydrological cycle by which water is transferred from the Earth's surface to lower atmosphere. With spatiotemporal variations, ET plays a crucial role in the global ecosystem and affects vegetation distribution and productivity, climate, and water resources. China features a complex, diverse natural environment, leading to high spatiotemporal heterogeneity in ET and climatic variables. However, past and future ET trends in China remain largely unexplored. Thus, by using MOD16 products and meteorological datasets, this study examined the spatiotemporal variations of ET in China from 2000 to 2019 and analyzed what is behind changes, and explored future ET trends. Climate variation in China from 2000 to 2019 was statistically significant and had a remarkable impact on ET. Average annual ET increased at a rate of 5.3746 mm yr^-1 (P < 0.01) during the study period. The main drivers of the trend are increasing precipitation and wind speed. The increase in ET can also be explained to some extent by increasing temperature, decreasing sunshine duration and relative humidity. The zonation results show that the increase in temperature, wind speed, and precipitation and the decrease in relative humidity had large and positive effects on ET growth, and the decrease in sunshine duration had either promoting or inhibiting effects in different agricultural regions. Pixel-based variations in ET exhibited an overall increasing trend and obvious spatial volatility. The Hurst exponent indicates that the future trend of ET in China is characterized by significant anti-persistence, with widely distributed areas expected to experience a decline in ET. These findings improve the understanding of the role of climate variability in hydrological processes, and the ET variability in question will ultimately affect the climate system.

Distribution of ecological restoration projects associated with land use and land cover change in China and their ecological impacts

China is prone to broad land degradation and thus has been implementing ecological restoration projects (ERPs) since the reform and opening up. The extent of ERPs, as well as the varied planting efforts including tree gain projects (TGPs), grass gain projects (GGPs), and shrub gain projects (SGPs), have remained largely unknown. In addition, the mixed success of ERPs on preventing soil erosion and improving biodiversity is not well known. Based on a land use and land cover (LULC) product and a trajectory-based change detection approach, we successfully generated the first national map of ERPs associated with land use and land cover change (LUCC) and its three associated subcategories. Then, we applied the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model to evaluate the dynamics of sediment retention and habitat quality. In addition, we explored the heterogeneous patterns for the ecological impacts of ERPs. Our results suggested that during the past 40 years, a total ERP area of 9.54 × 10⁶ hm² was observed nationwide, mainly in the northwestern provinces of China. Of the three ERP subcategories, TGPs accounted for the largest area (48.55%), followed by GGPs (47.50%) and SGPs (3.96%). The national average sediment retention experienced a significant increase, whereas the national average habitat quality experienced a significant decline. ERP-driven increases in habitat quality were offset partly by the LUCCs induced by economic development policies in some regions, especially in northeast China. The simultaneous effect of construction land expansion and ERP implementation on sediment retention made the synchronization between ERP implementation and sediment retention improvement insignificant. We also suggested the optimal direction for ERP implementation.

Using the Auction Price Method to Estimate Payment for Forest Ecosystem Services in Xin’an River Basin in China: A BDM Approach

Accurately estimating the forest farmers’ protection costs for forest ecosystem services has become a hot issue in ecological economics. In this research, we propose a novel method of using an auction price model to evaluate the forest ecosystem services. We establish a functional relationship between forest farmers and the forestland that belongs to them based on experimental data from Xin’an River Basin in China. The results indicate that the average willingness of farmers to accept payment for forest ecosystem service protection in the low, middle, and high levels of forest quality is 17,123.10, 23,493.75, and 31,064.40 yuan/ha/year, respectively. Moreover, farmers with different individual characteristics, household characteristics, planting characteristics, policy cognition, and ecological awareness are also willing to be paid differently. This research can provide a reference for forest ecosystem protection policies and assist the sustainable forestry development.

Carbon Sink under Different Carbon Density Levels of Forest and Shrub, a Case in Dongting Lake Basin, China

Terrestrial ecosystems play a critical role in the global carbon cycle and climate change mitigation. Studying the temporal and spatial dynamics of carbon sink and the driving mechanisms at the regional scale provides an important basis for ecological restoration and ecosystem management. Taking the Dongting Lake Basin as an example, we assessed the carbon sinks of forest and shrub from 2000 to 2020 based on the maps of biomass that were obtained by remote sensing, and analyzed the dynamics of carbon sinks that were contributed by different biomass carbon density levels of constant forest and shrub and new afforestation over the past two decades. The results showed that the carbon sink of forest and shrub in the Dongting Lake Basin grew rapidly from 2000 to 2020: carbon sink increased from 64.64 TgC between 2000 and 2010, to 382.56 TgC between 2010 and 2020. The continuous improvement of biomass carbon density has made a major contribution to carbon sink, especially the carbon density increase in low carbon density forests and shrubs. Carbon-dense forests and shrubs realized their contribution to carbon sink in the second decade after displaying negative carbon sink in the first decade. Carbon sink from new afforestation increased 61.16% from the first decade to the second decade, but the contribution proportion decreased. The overall low carbon density of forest and shrub in the Dongting Lake Basin and their carbon sink dynamics indicated their huge carbon sequestration potential in the future. In addition to continuously implementing forest protection and restoration projects to promote afforestation, the improvement of ecosystem quality should be paid more attention in ecosystem management for areas like Dongting Lake Basin, where ecosystems, though severely degraded, are important and fragile, to realize their huge carbon sequestration potential.

Spatio-Temporal Variations and Socio-Economic Driving Forces for Wetland Area Changes: Insights from 2008–2017 Data of Yunnan Province, China

An in-depth understanding of the associations between variations in the wetland area and socio-economic driving forces is essential owing to rapid urbanization. However, to date, no study has performed a quantitative study on the relationships between spatio-temporal patterns for wetland area variations and socio-economic driving factors in Yunnan Province. Based on Statistical Yearbook data, we found that during 10 years, different types of wetlands exhibited different change rates, with obvious spatial heterogeneity. The overall increase in wetland area in Yunnan Province was 13.35%, of which the increases in river, lake, and swamp wetland areas were 46.39%, −3.12%, and 295.56%, respectively. At the city level, the maximum decrease and increase in total wetland area were noted in Xishuangbanna (−84.30%) and Diqing (+185.22%), respectively. A total of 9 of 24 factors which were further selected according to collinearity diagnostics might help interpret changes in the wetland area of Yunnan Province according to the regression analysis results (R2 = 0.749, p < 0.01). Moreover, in different city development periods, the key socio-economic factors were different, which should be considered separately when formulating policies. Our results may clarify the socio-economic influencing factors for wetland spatio-temporal changes and help to guide policymakers.

Increasing collaboration between China and India in the environmental sciences to foster global sustainability

As the two largest countries by population, China and India have pervasive effects on the ecosphere. Because of their human population size and long international boundary, they share biodiversity and the threats to it, as well as crops, pests and diseases. We ranked the two countries on a variety of environmental challenges and solutions, illustrating quantitatively their environmental footprint and the parallels between them regarding the threats to their human populations and biodiversity. Yet we show that China and India continue to have few co-authorships in environmental publications, even as their major funding for scientific research has expanded. An agenda for collaboration between China and India can start with the shared Himalaya, linking the countries' scientists and institutions. A broader agenda can then be framed around environmental challenges that have regional patterns. Coordinated and collaborative research has the potential to improve the two countries' environmental performance, with implications for global sustainability.

Enhancing Ecosystem Services in the Agro-Pastoral Transitional Zone Based on Local Sustainable Management: Insights from Duolun County in Northern China

Ecosystem and associated ecosystem services (ESs) in the agro-pastoral transitional zone of northern China (APTZNC) are sensitive to climate change and human activities. Essential to designing targeted policy interventions toward achieving sustainability in the APTZNC is a comprehensive understanding of the spatiotemporal changes in ESs and their drivers. This study identified the spatiotemporal changes in six ESs in Duolun County from 2000 to 2017. The impacts of drivers—temperature, precipitation, wind speed, vegetation cover (FVC), land use/cover (LULC), soil type, altitude, and slope—on the changes in the ESs in the county and its ecological production zones were then explored. The results indicated that the six ESs improved during the study period. The drivers influencing changes in ESs over time exhibited similarities across regions. Although FVC contributed to improvements in the food supply, grass production, carbon sequestration, and soil wind erosion (SLwind), it also reduced water yield, which may exacerbate the water shortage in arid and semi-arid areas. In regions where the ecology was in the recovery phase, especially in slope farmland, the inhibition of soil water erosion (SLwater) by FVC was easily offset by the higher SLwater potential from increased precipitation. The decrease in wind speed improved the regional ESs, whereas the increase in temperature posed a threat to SLwind. The drivers affecting the spatial patterns of ESs varied among zones. Across the three zones, the greater influential drivers of ESs were FVC and LULC. The impacts of topographic drivers and soil type on the distribution of ESs should also be noted in the agro-zone and agro-pastoral zone, respectively. Our study advocated that ES management should be adjusted to local conditions, and differentiated planning policies should be implemented in line with the ecological characteristics in the APTZNC, which will contribute to regional ecological sustainable development.

Defining Household Typologies Based on Cropland Use Behaviors for Rural Human-Environment Systems Simulation Research: A Case Study in Southwest China

The dynamics of rural human-environment systems in developing countries have increasingly been attracting attention. Agent-based modeling (ABM) is a valuable simulation tool for detecting complex feedback loops in rural human-environment systems with a ‘bottom-up’ approach. However, such models require the prerequisite analysis of household typology to simulate households’ decision-making process, where a gap exists between having accurate classification criteria and a simplified modeling framework. This study aimed to develop a household typology for two selected counties in southwest China based on multivariate analysis techniques and the classification tree method. Four categories of socioeconomic variables, including labor conditions, resource endowments, economic status, and social connections, were screened as possible factors impacting agriculture practice decisions. The results showed that household diversification in the study area was mainly determined by diversified livelihood strategies of off-farm work, livestock breeding, subsidy dependence, and traditional planting. Five distinct household types were identified: non-farm households, part-time households, livestock breed households, subsidized households, and traditional planting households. The household types were associated with specific cropland use behaviors, and their decision-making behaviors were verified with bounded rationality theory (where the maximization of profits is the primary goal). The quantitative classification criteria obtained in this study were clear and could be easily identified and used by ABMs. Our study provides a basis for further simulation of the complicated rural human-environment systems in southwest China.

Analysis of the Gross Ecosystem Product—Gross Domestic Product Synergistic States, Evolutionary Process, and Their Regional Contribution to the Chinese Mainland

The trade-off and synergy relationship between ecosystem services (ESs) and human well-being (HWb) in the land-use process has become a research hotspot. The evolutionary process and regional contribution of the accurate quantification of ESs and HWb can provide a reference for government departments to formulate macroeconomic policies. Therefore, this study first constructed an analysis framework to identify the synergistic states/evolutionary stages of the gross ecosystem product (GEP) per capita (PGEP) and gross domestic product (GDP) per capita (PGDP) and the regional contribution of the GEP–GDP synergy of 362 municipal units in mainland China from 2000 to 2015. We did this by employing the Markov transition probability matrix, land use data, and economic data based on satellite remote sensing images. The findings of this study show that (1) the PGEP of the Chinese mainland has a remarkable spatial divergence featuring a higher value in the northwestern Chinese mainland and a lower value in the southeastern Chinese mainland on both sides of the Hu Line during the investigation period; despite the eastern Chinese mainland having a higher PGDP, the PGDP at the national level is distributed in dispersion on both sides of the Hu Line; (2) during the first half of the investigation period, the GEP–GDP synergy in the Chinese mainland was generally in the pseudo-synergy stage or the transition stage from pseudo-synergy to primary/intermediate synergy, while in the second half of the period, the GEP–GDP synergy in the Chinese mainland continued to improve; (3) the GEP–GDP synergy was relatively stable on the Chinese mainland during the investigation period, with 24.28% of the units shifting to a lower or higher level synergy, and the GEP–GDP synergy was more stable in the western and central Chinese mainland, while it was more likely to shift to a higher state in the northeastern and eastern Chinese mainland. This study suggests that the GEP–GDP relationship varies with spatial scales; a hierarchical, multiscale approach is necessary to study and improve both of these relationships, as simply extrapolating policies across single administrative levels may lead to unintended outcomes.

Land-use-mediated inconsistency of changes in the provision and delivery of soil erosion control services at the watershed scale

Soil erosion control services (SECSs) are the benefits delivered to people derived from preventing the negative impacts of soil erosion, such as avoiding the loss in soil productivity and preventing the damage to infrastructures such as dams and roads. SECS is derived from the functions of the ecosystems and is delivered to people through physical processes and social activities. The land-use change (LUC) reshapes the SECSs supply capacity, the SECS flow over the landscape, and the related benefit people received. Numerous studies have revealed how LUC shapes the SECSs supply capacity. However, the SECSs flow to local communities, and the LUC-derived SECS flow dynamics remain unclear. This study quantified the SECSs delivered to local communities following a land-use-specific cascade mechanism and using the WATEM/SEDEM framework. The effects of on-site soil erosion and sediment delivery over the watershed were combined. The cultivated lands were considered as the conveyers of SECSs. The study revealed the inconsistency of temporal change in SECS provision and the actual SECSs delivery to local communities. The results illustrated the increased capacity for soil erosion prevention and sediment flow reduction and a consequent increase in SECS supply capacity. However, the total amount of actual SECSs delivered to the local communities was declined due to the land-use change featured in reduced cropland area. The results imply that changes in SECS provision capacity cannot directly indicate the changes in SECS delivery to local communities. Though the modeled SECSs did not cover all SECSs in this region, this study highlights the effectiveness of the land-use-specific cascade framework in describing the delivery of SECSs and the importance of addressing the delivery processes of ecosystem services from ecosystem to people.

Trade-off between tree planting and wetland conservation in China

Trade-offs between tree planting programs and wetland conservation are unclear. Here, we employ satellite-derived inundation data and a process-based land surface model (ORCHIDEE-Hillslope) to investigate the impacts of tree planting on wetland dynamics in China for 2000–2016 and the potential impacts of near-term tree planting activities for 2017–2035. We find that 160,000–190,000 km² (25.3–25.6%) of historical tree planting over wetland grid cells has resulted in 1,300–1,500 km² (0.3–0.4%) net wetland loss. Compared to moist southern regions, the dry northern and western regions show a much higher sensitivity of wetland reduction to tree planting. With most protected wetlands in China located in the drier northern and western basins, continuing tree planting scenarios are projected to lead to a > 10% wetland loss relative to 2000 across 4–8 out of 38 national wetland nature reserves. Our work shows how spatial optimization can help the balance of tree planting and wetland conservation targets.

Afforestation and reforestation programs aimed at enhancing carbon sequestration may have unintended effects on non-forest ecosystems and biodiversity. Here the authors use remote sensing and land surface modelling to quantify trade-offs between tree planting and wetland conservation in China

How does the local-scale relationship between ecosystem services and human wellbeing vary across broad regions?

Recent studies have shown that the relationships between ecosystem services (ES) and human wellbeing (HWB) can be positive, negative, or non-existent, but the underlying causes and processes remain unclear. This study aimed to investigate how and why the local level ES-HWB relationship would change geospatially and manifest on broad regions. Using data for Mainland China, we first calculated seven ES and Human Development Index (an indicator of HWB), then used geographically weighted regression and cluster analysis to quantify the county-level ES-HWB relationship, and finally adopted Wilcoxon test and random forest to investigate key influencing factors. We found that (1) the local-scale relationship between ES and HWB exhibited a great deal of spatial heterogeneity, varying from positive to negative or no correlations across broad regions; (2) the varying relationships merged spatially into three general types of regions: Positive Correlation-Dominant Region, Negative Correlation-Dominant Region, and No Correlation-Dominant Region; and (3) the variations and spatial patterns of the ES-HWB relationships were influenced by a number of social-ecological factors (e.g., population density and land cover compositions), and generally corresponded to different stages of land use transition and socioeconomic development: a positive ES-HWB relationship was found mainly in socioeconomically underdeveloped (rural or agricultural) regions with low ES production levels; a negative ES-HWB relationship occurred mostly in intermediately developed regions with abundant non-food ES; and ES and HWB had no relationships in socioeconomically well-developed (intensive agriculture/urbanized) societies with ample provisioning ES. These findings suggest that neither the "environmentalist's paradox" nor the "environmentalist's expectation" adequately accounts for the complexity of the ES-HWB relationship.

An integrated remote sensing and model approach for assessing forest carbon fluxes in China

Forest plays an important role in reducing pressure on the natural environment, weaking the influence of greenhouse effects, and sequestrating atmospheric carbon dioxide. So far, due to the lack of complete understanding of forest ecosystem processes and the limitations on the scope of application of evaluation methods, there are still great uncertainties in the researches on carbon fluxes of forest ecosystems in China at the national level. In this study, an individual tree species FORCCHN model, which could flexibly use the inventory data as the initial field (more accurately) or use the remote sensing information to inverse initial field was applied. The dynamics of key carbon cycle fluxes (net primary productivity (NPP) and net ecosystem productivity (NEP)) and carbon sequestration of forest ecosystems in China from 1982 to 2019 were simulated based on remote sensing data and FORCCHN model. The results showed that forest ecosystems in China had great carbon sequestration potential over the past 39 years. From 1982 to 2019, the NPP of Chinese forests presented a fluctuated increase. Total NPP from 2011 to 2019 ranged from 0.91 PgC·a^-1 to 1.14 PgC·a^-1. Annual average NEP of forest ecosystems in China from 2011 to 2019 was 0.199 PgC·a^-1 (1Pg = 10¹⁵ g). Influenced by climate, soil and vegetation, carbon sequestration potential in Chinese forest ecosystems presented obvious regional differences in space. The spatial distribution of NEP gradually increased from Northwest to Southeast China. From 2011 to 2019, forests in Yunnan Province had the strongest carbon storage capacity (72.79 TgC·a^-1, 1Tg = 10¹² g), followed by forests in Guangxi (18.49 TgC·a^-1) and forests in Guangdong (10.01 TgC·a^-1). Our results not only address concerns about carbon sequestration but also reflect the importance of Chinese forest resources in the development of the national economy and society.

Assessment of ecological restoration projects under water limits: Finding a balance between nature and human needs

Revegetation has significantly contributed to improvements in ecosystem services, such as carbon sequestration and soil retention. Yet, vegetation expansion in water-limited regions may generate conflict of water demand between nature and humans. Present studies are still lacking when it comes to identifying the permissible vegetation capacity, i.e. net primary productivity (NPP) threshold, based on the local water resources limits, and further proposing adjustment and optimization strategies to keep water use balanced in anthropogenic-biological systems. Under such a circumstance, this study assesses the difference between the actual NPP and NPP thresholds at regional and ecosystem scales in China. The results show that 8 out of 31 provinces have their provincial actual NPP above the regional NPP thresholds, mainly concentrated in northern China between 400 and 800 mm iso-precipitation line, i.e. North China Plain (Beijing-Tianjin-Hebei), the middle reaches of the Yellow River Basin (Shaanxi and Henan provinces), and the Northeast China (Heilongjiang, Jilin and Liaoning). Forest ecosystems dominate the difference between the actual total woodland and grassland ecosystems NPP and the permissible NPP thresholds in these regions, ranging from 67% (Beijing) to 99% (Tianjin). If the current vegetation intensity in these regions remains unchanged, the areas of woodland and grassland ecosystems should be optimized 0-48% and 0-100% of their present areas to balance the water demand between the ecosystems and humans, without considering the potential consequence of climate change and soil erosion. Although 23 provinces have their regional actual NPP below their permissible NPP thresholds, 6 out of 23 provinces still have their woodland and grassland ecosystems NPP above the corresponding NPP thresholds, mainly focusing on the Northwestern China north over the 400 mm iso-precipitation line, including Inner Mongolia, Qinghai, Hainan, Shanxi, Gansu and Xinjiang. Forest ecosystems also dominate the negative NPP differences in these regions, ranging from 91% (Inner Mongolia) to 46% (Gansu). These reveal the hidden and potential pressure in the 6 provinces to balance limited water resources in the local anthropogenic-biological system. This study provides a method to assess the water-resources permissible NPP threshold and further proposes the specific adjustment and optimization plans for the areas with actual NPP above the corresponding NPP thresholds, which can provide guidance for ecological restoration program implementations in a more sustainable way.

The Trade-Offs and Synergies of Ecosystem Services in Jiulianshan National Nature Reserve in Jiangxi Province, China

Ecosystem services are directly related to human well-being. Previous studies showed that management policies and human activities alter the trade-offs and synergies of ecosystem services. Taking effective measures to manage the trade-offs and synergies of ecosystem services is essential to sustain ecological security and achieve a “win-win” situation between society and ecosystems. This study investigated the spatiotemporal changes of water yield, soil conservation, and carbon sequestration in the Jiulianshan National Nature Reserve from 2000 to 2020 based on the InVEST model. We distinguished spatial patterns of trade-offs and synergies between ecosystem services using the correlation relationship analysis. Then we analyzed the response of ecosystem services relationships among different vegetation types and elevation bands. The results showed that water yield and carbon sequestration presented an overall upward trend, while soil conservation remained a marginal degradation. Rising ecosystem services were mainly in the central, western, and southeastern regions, and declining areas were mainly distributed in the midwestern and northeastern fringes. Synergies spatially dominated the interactions among water yield, soil conservation, and carbon sequestration, and the trade-offs were primarily concentrated in the northern, southern, and southwestern fringes. Among the different vegetation types, synergies dominated ecosystem services in broad-leaved forests, coniferous forests, mixed forests, and Moso bamboo forests and in grass. The trade-offs were gradually reduced with elevation. This study highlighted that trade-off of ecosystem services should be incorporated into ecological management policies, strengthening the effectiveness of nature reserves in protecting and improving China’s ecosystem services.

An ecological perspective for understanding regional integration based on ecosystem service budgets, bundles, and flows: A case study of the Jinan metropolitan area in China

Regional integration can contribute to co-occurring benefits of different parts of an urban agglomeration by managing these parts as a whole. However, current regional integration mainly focuses on the socioeconomic rather than the ecological dimension. To interpret regional ecological integration, we firstly selected six typical ecosystem services (ESs) to represent ecological benefits that potentially need to be improved by ecological integration for further analysis. Then we used ES budgets, bundles, and flows to investigate the potential, basic analysis unit, and occurring manners of ecological integration, respectively. Our results show that supply-demand mismatches were observed in all the ES types. Meanwhile, coexisting ES surpluses and deficits on the town scale were found in supporting biodiversity, soil retention, water yield, green space recreation, and crop yield, which indicates that their supply-demand mismatches can be mitigated with ecological integration. Furthermore, all the towns were classified into five spatial clusters with distinct ES budget bundles, which acted as the basic analysis unit of ecological integration. ES flows with three flow characteristic types were observed between different clusters, and all the clusters had ES provider-beneficiary relationships with each other. Based on the ES approach, we provided an ecological perspective for understanding regional integration, which has the potential to promote regional ecological sustainability.

Quantifying impacts of climate dynamics and land-use changes on water yield service in the agro-pastoral ecotone of northern China

Large-scale revegetation practices have lasted approximately two decades in the agro-pastoral ecotone of northern China (AENC), and their impacts on hydrological and ecological effects remain poorly understood. Previous studies largely focused on assessing water yield service (WYs) based on several fixed time points, whereas time series information-continuous WYs dynamics were more reliable and valuable in decision-making about water sustainability goals. This study analyzed the interannual WYs trend and relative roles of its drivers in the last 20 years based on a newly proposed approach, and revealed the past, present and future impacts of revegetation on WYs. The final results indicated that the annual WYs averaged approximately 97 mm and exhibited an increasing trend of 1.96 mm year^-1 (p = 0.086) during 2000-2019, in which climate and land-use changes were responsible for 88% and 12% of WYs variations, respectively. From 2000 to 2019, WYs was pronouncedly 1.47 mm year^-1 (p = 0.119) lower in the afforestation area than in the nonafforestation area, but the precipitation in the two regions had a statistically insignificant difference (p = 0.97). Future revegetation scenarios showed great potential for the shrinkage of WYs provision, even approaching a maximum of 50 mm at a local scale. Even so, the afforestation-induced reductions in blue water and benefits in green water both should receive equal attention. Specifically, any attempts to assess WYs or other climate-driven ecosystem services using discontinuous years as the study period must be taken with extreme caution.

Spatio-Temporal Changes in Ecosystem Service Value and Its Coordinated Development with Economy: A Case Study in Hainan Province, China

Ecosystem service value is crucial to people’s intuitive understanding of ecological protection and the decision making with regard to ecological protection and economic green development. This study improved the benefit transfer method to evaluate ESV in Hainan Province, proposed the coupling analysis method of economic and environmental coordination, and explored the relationship between ESV and economic development based on the medium-resolution remote sensing land use data and socio-economic data from 2000 to 2020. The results show that Hainan Province’s ESV decreased by 33.305 billion CNY from 2000 to 2020. The highest ESV per unit area was found in the water system and forest ecosystem, mainly distributed in the central mountainous area. The overall condition of EEC decreased from a basic coordination state to a moderate disorder state. Areas with high economic development had better EEC, such as Haikou and Sanya. Meanwhile, we analyzed the driving force of ESV and EEC by Geodetector. The results show that land use intensity was the most important driving factor affecting ESV, with a contribution rate of 0.712. Total real estate investment was the most important driving factor affecting EEC, with a contribution rate of 0.679. These results provide important guidance for the coordinated development of regional economy and ecosystem protection.

Research on the coordinated development of ecosystem services and well-being in agricultural and pastoral areas

Payment for Ecosystem Services (PES) has been widely accepted as a policy tool for promoting ecological and social progress. However, PES development and implementation in traditional agricultural and pastoral areas are often more challenging than in other areas. The contradiction between ecological protection and people's livelihood development in traditional agricultural and pastoral areas is related to developing country's sustainable development strategy. Based on this, we evaluate the PES (ERCCP: the Ecological Relocation and Capital Compensation Program) program in Tianzhu County, as a case study to investigated the impact of ERCCP on the local natural and social ecosystems on a 20-year scale. The results of indicated that ERCCP has achieved "win-win" gains of restoring environment and promoting socioeconomic development: in the 10 years since ERCCP was implemented, the area of forest land and grassland increased significantly, increasing by 1135.6 ha and 919.62 ha, respectively. 57.5% of farmland was converted to grassland and 30.8% to forest, respectively. In addition, 92.2% and 7.5% of bare land were replaced by grassland and forest, respectively, indicating a gradual recovery of green land during this period. We also analyzed the effects of ERCCP on social systems, and found that the change of agro-pastoralists' attitude towards ERCCP promoted the transfer of labor force from the primary industry to the tertiary industry, accelerated the development of urbanization, and made the poor population completely out of poverty by 2020. In addition, we predict that the income level of households, the PES return on investment of local governments, and the value of regional ecosystem services will increase significantly after 2025. In this context, We establish a theoretical model to explain the win-win plan for the coordinated development of ecosystem services and regional well-being to explore the sustainability of PES and provided a typical case for the similar research area in the world, especially in the areas with the ecological fragility and poverty problems.

"Targets-Plans-Decision": A framework to identify the size of protected areas based on the balance of ecological protection and economic development

A framework called "Targets-Plans-Decision" (TPD) was established for identifying the size of adequate protected areas (PAs) based on the combination of species distribution probability prediction method, systematic conservation planning (SCP) theory, and protection efficiency analysis, to achieve a balance between ecological protection and economic development. The first step of the framework is to determine the protection targets. In this study, the protection targets were defined as important habitats and important ecosystems. The second step is to identify the PAs plans of different sizes. We adopted a SCP method, which takes into account cost-effectiveness while delineating the PAs. The third step is to determine the optimal size of the PAs through ecological protection efficiency analysis. We constructed the protection efficiency index (PEI), which is the protection cost per unit area. Then we used Kaya identity (a structural decomposition method) to decompose PEI. The decomposed PEI included value density (ecological value per unit area) and value cost (cost to realize unit ecological value). By analyzing the changes of the two, the optimal size of the PAs can be determined. We took Nanchang as an example to conduct an empirical study to verify the usability of the TPD framework. The result shows the TPD framework proposed in this study can effectively identify the optimal size of PAs and contribute to forming a cost-effective ecological protection plan. When the size of PAs was set to 70% of the important habitats and important ecosystems, it was most beneficial for ecological protection. Furthermore, the optimal protection efficiency plan recommended by the TPD framework improved the efficiency of ecological protection. The TPD framework can serve as a basis for the size identification of PAs and also support the delineation of PAs worldwide.

Ecosystem restoration programs challenges under climate and land use change

Ecological restoration programs have significantly contributed to the improvement of ecosystem services in the past two decades. However, due to climate change and rapid land use change, planning and management of ecosystem services restoration programs are still challenging, particularly how to identify and quantify the specific contribution of natural and human drivers of ecosystem services dynamics, how to assess and simulate the integrated impacts of climate-land use change interactions on changes in ecosystem services, insufficient simulation of mid- and long-term impacts of different ecological restoration programs, and lack of identification of ecological restoration thresholds. To overcome the challenges, we propose a new framework for restoring ecosystem services programs as potential solutions to the challenges. The framework includes attribution analysis of changes in ecosystem services, assessment and projections of ecosystem services dynamics under the integrated impacts of climate-land use change interactions, simulation of mid- and long-term effects of ecological programs and identification of ecological restoration threshold, which forms the logic chain of the framework, i.e. theory foundation-techniques support-application cases-policy implications. We finally recommend four related research directions and steps forward to overcome the challenges, including (1) Step 1: establish attribution analysis method of ecosystem services dynamics based on ecological thermodynamics and partial differential equation; (2) Step 2: Assess and simulate the impacts of coupled climate-land use change interactions on ecosystem services dynamics; (3) Step 3: Simulate the mid- and long-term impacts of different ecological restoration programs; and (4) Step 4: Identify ecological restoration thresholds. This study could provide insights for improving management of ecosystem services restoration programs in the context of rapid land use change and continuous climate change.