Improvement of ecosystem quality in National Key Ecological Function Zones in China during 2000-2015

Reeve's Muntjac (Muntiacus reevesi) Habitat Suitability Under Climate Change Scenarios in Hupingshan National Nature Reserve, China

Climate change and human disturbance are critical factors affecting the habitat distribution of wild animals, with implications for management strategies such as protecting migration corridors, habitat restoration, and species conservation. In the Hupingshan National Nature Reserve (NNR), Reeve's muntjac (Muntiacus reevesi) is a key prey species for the South China tiger (Panthera tigris amoyensis), which is extinct in the wild and targeted for reintroduction by the Chinese government. Thus, understanding the habitat distribution and abundance of Reeve's muntjac is essential to ensure the survival and sustainability of reintroduced tiger populations. Despite significant conservation efforts, the impacts of climate change and human disturbance on Reeve's muntjac habitat distribution in Hupingshan NNR remain unclear, though these factors could necessitate adaptive tiger management strategies due to shifts in prey abundance. In this study, we employed an optimized MaxEnt model to assess current habitat distribution and identify key environmental variables influencing the habitat distribution of Reeve's muntjac. Assuming non-climatic environmental factors will remain constant over the next century, we projected future habitat distribution under two shared socioeconomic pathways (SSP126 and SSP585) for the mid-century (2050s) and the late-century (2090s). Comparative analyses of current and projected habitat areas revealed potential impacts of climate change on this species. MaxEnt outputs classified habitat suitability into high, medium, and low levels. Results showed that climatic and human disturbance factors contributed 35.2% and 49.4% to habitat suitability, respectively. Under the SSP126 scenario, habitats with decreased suitability covered 0 km2 in the 2050s, expanding slightly to 4.2 km2 in the 2090s, while those with increased suitability spanned 491.1 km2 (2050s) and 463.2 km2 (2090s). Under the SSP585 scenario, habitats with decreased suitability covered 10.2 km2 in the 2050s and 431.8 km2 in the 2090s. Habitats with increased suitability were comparatively smaller under SSP585, covering 162.0 km2 (2050s) and 1.1 km2 (2090s). These findings suggest that while mid-century climate projections (SSP126 and SSP585) may support Reeve's muntjac's survival, habitat loss is projected by 2090s (SSP126). Thus, future climate change may lead to decreased habitat suitability and increased fragmentation, raising extinction risks for Reeves's muntjac. Mitigating these effects could involve establishing migration corridors, minimizing human disturbances, and potentially supplementing prey populations with captive-bred prey. Such measures are essential to support the South China tiger reintroduction plan and help ensure that prey availability remains sufficient for sustaining reintroduced tiger populations.

Optimal allocation of technical reclamation and ecological restoration for a cost-effective solution in Pingshuo Opencast Coal Mine area of China

Limiting adverse consequences of mining activities requires ecosystem restoration efforts, whose arrangement around mining areas is poorly designed. It is unclear, however, where best to locate ecological projects to enhance ecosystem services cost-effectively. To answer this question, we conducted an optimized ecological restoration project planning by the Resource Investment Optimization System (RIOS) model to identify the restoration priority areas in the Pingshuo Opencast Coal Mine region in Shanxi Province. This region features notable mining activity, agricultural land use, and urban development. We found that the land use changes were primarily influenced by human activities such as mining and urbanization, as well as ecological interventions from 1986 to 2022, during which the area of industrial and construction land continuously expanded. The RIOS model was configured using input data such as land use, digital elevation models (DEM), and biophysical coefficients. Ecological restoration objectives were selected, including Erosion Control for Drinking Water Quality, Erosion Control for Reservoir Maintenance, Nutrient Retention, and Baseflow. Investment optimization scenario simulations revealed that over 90% of ecological projects in the Pingshuo Opencast Coal Mine are distributed in the low-slope areas (0°-15°). Four types of technical reclamation and ecological restoration projects, i.e., agroforestry, grass strips, riparian management, and terracing, exhibit strong preferences for specific locations. Riparian management and agroforestry tend to be distributed on soil dumps; terracing and grass strips tend to be distributed in the upstream agricultural areas of rivers and junctions of watershed gullies and slopes. The model prioritized areas based on ecological restoration goals and stakeholder interests, optimizing locations that would maximize ecological benefits while addressing the objectives. Moreover, depending on the different goals of ecological restoration in the mining area, investment plans that maximize benefits for stakeholders should range between 3 and 6 million dollars. While the restoration strategies in this study were designed for the Pingshuo region, they hold potential for other mining areas with similar biophysical conditions, surrounding ecosystems, and mining scales. The RIOS model adjusts its recommendations based on specific input data, making it adaptable and broadly applicable to other mining area. The results of this study positively contribute to alleviating the conflict between ecosystem protection and socioeconomic development in mining areas, scientifically regulating ecological restoration activities, and enhancing ecosystem services. Our results provide evidence that ecological restoration interventions contribute measurably to restore the degraded ecosystems in the mining areas.

Evaluation of ecosystem quality and stability based on key indicators and ideal reference frame: A case study of the Qinghai-Tibet Plateau

China has explicitly prioritized the enhancement of ecosystem quality and stability(EQS) as a governmental objective. However, our understanding of systematic and comprehensive assessment methods for EQS remains limited. The development and investigation of corresponding evaluation frameworks and their underlying mechanisms remain insufficiently explored. This study employs the concept of an "ideal reference system and key indicators," integrating diverse ecosystem and human activity characteristics from perspectives such as ecosystem structure, function, and landscape vulnerability, to determine indicator weights using the Analytic Hierarchy Process(AHP) and entropy weight method, thereby constructing an evaluation framework for assessing the quality and stability of the Qinghai-Tibet Plateau(QTP) ecosystem. The spatiotemporal variations in EQS from 2000 to 2018 were examined, and the key driving factors were identified using the optimal parameter-based geographical detector (OPGD). The results indicate that the EQS of the QTP exhibit a spatial distribution pattern characterized by higher values in the southeast and lower values in the northwest. From 2000 to 2018, there has been a consistent improvement in the overall ecosystem quality and stability across the QTP. The EQS exhibit a significant synergistic effect, with high-high(26.59 ± 1.26%) and low-low(32.61 ± 1.45%) matching combinations becoming the predominant regional patterns. However, in climatic transition zones and glacial areas, the relationship between these factors is particularly distinctive, indicating ecosystem response mechanisms specific to certain natural environmental conditions. Vegetation cover(>0.697), evapotranspiration(>0.620), and precipitation(>0.688) are the primary natural factors influencing EQS, while the impact of human activities has become increasingly significant. Furthermore, the research findings underscore the positive effects of the variable climatic conditions of the QTP on ecosystems within the context of global climate warming, while the stringent implementation of ecological protection measures has collectively contributed to the enhancement of EQS. The proposed evaluation framework not only facilitates a comprehensive and precise assessment of regional EQS, but also provides a scientific basis for understanding and managing the adaptive responses of plateau ecosystems under the complex interplay of natural and anthropogenic factors.

Improving grassland ecosystem services for human wellbeing in the karst desertification control area: Anthropogenic factors become more important

Elucidating the spatial and temporal patterns of grassland ecosystem service value (ESV) changes under different karst geomorphic types (KGTs) is crucial for promoting regional sustainable development and enhancing human well-being. Karst ecosystems are characterized by high spatial heterogeneity. However, analyses of the drivers of spatial and temporal changes in ESV in karst grasslands at multiple scales are lacking. In this study, the South China Karst (SCK) region was selected as the focus area, the gross ecosystem product (GEP) accounting method was used to quantify the grassland ESV from 2000 to 2020, and the GeoDetector model was used to elucidate the spatial and temporal evolution of the GEP, the drivers, and their interactions in different KGTs. The results indicate the following: (1) Over the past 20 years, the grassland GEP of SCK has increased from ¥ 14,844.24 × 108 in 2000 to ¥ 17,174.90 × 108 in 2020. Among the various KGTs, the karst gorge exhibited the fastest GEP increase (24.93 %) and karst hilly depressions the slowest (6.22 %). (2) The karst grassland GEP showed a strong positive spatial correlation with significant clustering characteristics (p < 0.05). (3) There are significant differences in the factors influencing the GEP of grasslands with different KGT values, and although they are generally influenced by factors such as NPP, precipitation, and population density, anthropogenic factors are becoming increasingly important. In addition, the multifactor interaction explained GEP better than the single factor. Based on our findings, we propose targeted grassland ESV restoration approaches and management recommendations for various KGTs dominated by distinct factors. Our results provide a scientific basis for decision-making regarding karst ecosystem service enhancement and value realization.

Linking the assessment of ecological engineering construction with zoning management in the typical agro-pastoral area of China: A perspective from quantity, quality and function

Combatting land damage has become a global priority, and China has adopted a series of ecological engineering measures, especially in the agro-pastoral area with fragile ecological environment. The effectiveness of ecological engineering construction (EEC), from a comprehensive recognition encompassing its quality, quantity, and function, has remained largely unknown. To this end, Zhangbei County, a typical agro-pastoral ecotone of northern China, was chosen as our focal area. After summarizing the timelines, aims and results of the EEC during various periods in Zhangbei, the linear spectral mixture analysis was employed to process Landsat 5 TM images in 2000 and 2010, as well as Landsat 8 OLI images in 2020. Then, a comprehensive evaluation framework of EEC was established from the perspective of "quantity-quality-function", and the ecological effectiveness of EEC was evaluated from 2000 to 2020 in Zhangbei. Results revealed that EEC played a critical role in enhancing quantity, quality and function, in spite of that, there were still numerous regions showing varying degrees of degradation in terms of these aspects. Then, by extending the three-dimensional cube as the theoretical basis for the zoning management of EEC, we merged four zones according to the space matching relationship among quantity, quality and function of EEC, namely, Ecological conservation area, Ecological improvement area, Ecological restoration area and Ecological remodeling zone. More targeted ecological measures were required for specific matching relationship among quantity, quality and function of EEC. This study is expected to present an empirical case for assessing the ecological effectiveness of EEC in areas or countries with similar restoration demand and support regional management.

Ecological barriers: An approach to ecological conservation and restoration in China

The Chinese government has pursued comprehensive ecological conservation and restoration by establishing an ecological barrier system. However, the majority of international research tends to focus on the connectivity between habitats, overlooking the functions that ecological barriers play in ecological conservation and restoration. The existing literature lacks a systematic exploration of the theory and practice of ecological barriers. This study employed the literature analysis tool CiteSpace to present the theoretical and developmental trends in ecological barriers from various perspectives, including research fields, historical evolution, research hotspots, and major research nations. By analyzing the differences in the understanding of ecological barriers between China and other countries, examining the ecological barriers construction history in China, and exploring the types and functions of ecological barriers, this study summarizes the framework of China's ecological barriers construction system as "features-functions-problems." Constructing an ecological barrier system can help achieve ecological conservation and restoration goals in China.

Effectiveness and driving mechanism of ecological restoration efforts in China from 2009 to 2019

Over the past decades, China's rapid economic growth and industrialization have led to serious ecological concerns. To combat ecological degradation and promote ecosystem sustainability, China has made substantial investments in ecological restoration in recent decades. Nevertheless, a comprehensive analysis of the effectiveness and driving mechanisms of these efforts are still lacking. Therefore, this study aims to bridge this gap by employing national land-use survey data to evaluate the effectiveness and driving mechanisms of China's ecological restoration efforts during 2009-2019, with a specific focus on ecological land preservation, land use structure, and their contribution to ecosystem services. Additionally, the Geodetector model was used to detect potential influencing factors and driving mechanisms of these efforts. The results of this study revealed that: (1) Between 2009 and 2019, a total of 585,492.61 km2 of non-ecological land was successfully transformed into ecological land through various ecological restoration efforts. Most of these areas were previously unused or cultivated land. (2) Forest and grass plantations were the major ecological restoration efforts in China, accounting for 47.35% and 41.91% of the total restored ecological land, respectively. Grassland restoration clustered northwest of the Hu Line, while forest restoration concentrated mainly to the southeast. Water and wetlands restoration were mainly distributed around China's major rivers, such as the Yangtze River and Yellow River. (3) China's ecological restoration efforts contributed to a 2.53 trillion CNY yuan increase in ecosystem service value during 2009-2019, with over 65% of the increase attributed to ecosystem regulating services. (4) China's ecological restoration efforts were mainly influenced by anthropogenic factors, such as population, land use, and urbanization, while the non-linearly enhanced interaction between natural and other factors also deserves attention. China should balance urban expansion, agricultural development, and ecological preservation, aligning restoration with socioeconomic trends while establishing effective inter-regional ecological compensation mechanisms.

Effects of large-scale land consolidation projects on ecological environment quality: A case study of a land creation project in Yan'an, China

Large land consolidation projects modify the structures and functions of regional ecosystems through the reshaping of the territorial spatial pattern, thereby affecting the ecological environmental quality (EEQ). To investigate the effects of large-scale land consolidation projects on EEQ, this study takes the major land consolidation project of "bulldoze mountains to create land" (BMCL) in Yan'an City as a research object and evaluates the change of EEQ based on Remote Sensing Ecological Index (RSEI). The consolidated area and the control area were set up to comparatively analyze the EEQ change processes and spatial distribution characteristics of these two areas in the full life cycle of BMCL. According to the results, the mean RSEI of the consolidated area was 0.128 lower than that of the control area, and the EEQ of the consolidated area was always lower than that of the control area. BMCL had a strong negative impact on the EEQ grade of the consolidated area, especially in the early stage. However, the positive effect of BMCL on EEQ gradually emerged in the late stage of the large land consolidation project. The overall EEQ grade of the consolidated area has also improved. The results of the stepwise regression analysis indicated that the wetness component and the normalized differential vegetation index played key roles in improving the EEQ of the BMCL. Overall, the local BMCL strongly affected the EEQ of the consolidated area but would not cause the EEQ of the whole region to experience any dramatic, abrupt change in the short term. This study provided references for the evaluation and analysis of the ecological effects of land consolidation at the regional scale, offering a feasible way to evaluate the spatio-temporal change of EEQ in BMCL.

Does green location-oriented policy enhance ecological resources and reduce air pollution? Empirical analysis from counties in China

Green location-oriented policy plays a vital role in improving the ecological security. Using the multi-phase difference-in-difference (DID) method, this study evaluates the impact of national key ecological functional areas (NKEFA) on ecological resources and environmental pollution. There are several important findings. Firstly, NKEFA effectively enhances ecological resources and reduces air pollution, the policy effect only manifests after two years of implementation. Secondly, NKEFA has indirectly improved air quality by promoting technological innovation, advanced industrial structure, and regional ecological resource quality. Moreover, the relationship between NKEFA and ecological resources is negatively regulated by industrialization and economic agglomeration, while the relationship between NKEFA and air pollution is positively regulated by them. Thirdly, NKEFA has the strongest impact on enhancing ecological resources in the eastern region, and it is more effective in reducing air pollution in the central and eastern regions compared to the western regions. Furthermore, the NKEFA demonstrates the greatest effectiveness in promoting ecological resources and reducing air pollution in water and soil conservation areas. However, there is a spatial spillover effect, which suggests that this policy has some negative impacts on the surrounding counties' ecological environment.

Spatio-Temporal Changes in Ecosystem Quality across the Belt and Road Region

The Silk Road Economic Belt and the 21st Century Maritime Silk Road Initiative (BRI) proposed in 2013 by China has greatly accelerated the social and economic development of the countries along the Belt and Road (B&R) region. However, the international community has questioned its impact on the ecological environment and a comprehensive assessment of ecosystem quality changes is lacking. Therefore, this study proposes an objective and automatic method to assess ecosystem quality and analyzes the spatiotemporal changes in the B&R region. First, an ecosystem quality index (EQI) is established by integrating the vegetation status derived from three remote sensing ecological parameters including the leaf area index, fractional vegetation cover and gross primary productivity. Then, the EQI values are automatically categorized into five ecosystem quality levels including excellent, good, moderate, low and poor to illustrate their spatiotemporal changes from the years 2016 to 2020. The results indicate that the spatial distributions of the EQIs across the B&R region exhibited similar patterns in the years 2016 and 2020. The regions with excellent levels accounted for the lowest proportion of less than 12%, while regions with moderate, low and poor levels accounted for more than 68% of the study area. Moreover, based on the EQI pattern analysis between the years 2016 and 2020, the regions with no significant EQI change accounted for up to 99.33% and approximately 0.45% experienced a significantly decreased EQI. Therefore, this study indicates that the ecosystem quality of the B&R region was relatively poor and experienced no significant change in the five years after the implementation of the "Vision and Action to Promote the Joint Construction of the Silk Road Economic Belt and the 21st Century Maritime Silk Road". This study can provide useful information for decision support on the future ecological environment management and sustainable development of the B&R region.

The local coupling and telecoupling of urbanization and ecological environment quality based on multisource remote sensing data

Coordinating the relationship between urbanization and ecological environment quality (EEQ) is crucial to achieving sustainable development. With the development of globalization, the pattern of remote interaction between urbanization and EEQ has gradually increased. However, the current study on the coupling of urbanization and EEQ lacks a remote perspective, and the remote sensing ecological index (RSEI) model has not yet considered the environmental pollution caused by population agglomeration. For these reasons, this study proposes the remote sensing ecological environment index (RSEEI) model and measures the local coupling and telecoupling coordination degree (LTCCD) of urbanization and EEQ in China from 2000 to 2020. According to the results, the rate of change of EEQ in China was -0.00011a^-1. RSEEI widens the gap between the east and west of EEQ, differentiated by the Heihe-Tengchong Line. China's urbanization is growing at a 0.0008a^-1 rate, with a spatially driven radiation potential with Beijing, Shanghai, Hong Kong, and Macao as the core. LTCCD follows an increasing trend from inland to coastal and west to east. Over 70% of provinces experienced a shift in adjacent LTCCD levels, and 14 provinces moved from disorder to coordination after 2010. The telecoupling strengthens the correlation between urbanization and EEQ among regions compared with traditional coupling. In addition, the eastern coastal areas, the northern and central-south inland areas, and the northwest face different coordination problems.

Co-benefits of the National Key Ecological Function Areas in China for carbon sequestration and environmental quality

Introduction

The National Key Ecological Functional Areas (NKEFAs) are location-oriented ecological engineering of China, which rely on the main functional area planning. The co-benefits of ecological product supply and ecological environment improvement of NKEFAs has not been fully assessed in the literature.

Methods

NKEFAs is considered a quasi-natural experiment, and the time-varying difference-in-differences (DID) model is used to assess the impact of NKEFAs on carbon sequestration (CS) and environmental quality (EQ) based on the panel data of 330 cities in China from 2001 to 2019. Then, we explore whether the co-benefits of ecological product supply and eco-environment protection can be achieved.

Results and discussion

NKEFAs can enhance CS and EQ and thus achieve co-benefits for both. NKEFAs can achieve the co-benefits of CS and EQ through territory spatial allocation and labor force aggregation, but industrial structure upgrading only positively mediates the impact of NKEFAs on CS. The co-benefits of CS and EQ are heterogeneous across functional area types, geospatial locations, and quantiles, while only CS at windbreak-sand fixation area, northwestern region, and low quantile regions is enhanced. This study makes a theoretical and methodological contribution to the existing literature on the policy effect assessment of ecological engineering. It also provides a comprehensive framework for evaluating the ecological effects of relevant policies in other countries by integrating the co-benefits of ecological products and eco-environment, analyzing regional heterogeneity, and exploring the underlying mechanisms.