Spatial relationships between ecosystem services and socioecological drivers across a large-scale region: A case study in the Yellow River Basin

Quantification of the provenance contribution and sedimentary mixing effect of sediments in the Yellow River Basin, China

Quantifying the source contributions of sediments in large fluvial systems with active wind erosion problems has crucial implications for understanding morphological evolution and ecological progression in the Earth system. Much effort have been focused on characterizing sediments of the Yellow River, but quantitation of the sediment source proportions at the basin-wide scale is lacking. To this end, the research aims to quantitatively elucidate the potential source contributions of sediments in the Yellow River based on geochemical characteristics and sediment fingerprinting technique, in order to identify sedimentary mixing effect and propose sustainable development strategies. In total, samples of four source groups (n = 107) and target floodplain sediments (n = 61) were collected and tested for elemental composition, grain size, magnetic susceptibility, and quartz grain microtextures. The results indicated that the optimal tracer combination was determined as P, Zn, and Ca. The average contributions of the "Tibetan Plateau", "Sandy deserts-Loess Plateau", "Loess Plateau", and "Loess Plateau-Qinling Mountains" source groups to the target sediments were 23.0 %, 21.5 %, 31.6 %, and 23.9 %, respectively. The accuracy of source apportionments was supported by the goodness of fit (GOF) and virtual mixtures tests. Meanwhile, large amounts of debris from surrounding mountains was transported to the Loess Plateau through fluvial processes and ultimately mixed with aeolian deposits, leading to sedimentary mixing effect. To maintain water balance and minimize erosion risk, the drought-resistant perennial planting and moderate grazing were recommended. The findings are instrumental in promoting soil and water conservation and disclosing fluvial and aeolian interaction on a global scale.

Cross-scale coupling of ecosystem service flows and socio-ecological interactions in the Yellow River Basin

As research on the full spectrum of ecosystem service (ES) generation and utilization within coupled human and natural systems (CHANS) has expanded, many studies have shown that the spatiotemporal dynamics of ESs are managed and influenced by human activities. However, there is insufficient research on how ESs are affected by bidirectional coupling between societal and ecological factors during spatial flow, particularly in terms of cross-scale impacts. These bidirectional influences between humans and nature are closely related to the utilization and transfer of ESs and affect the perception of spatiotemporal patterns of ESs and the formulation of management strategies. To fill this research gap, this study focuses on the Yellow River Basin (YRB), using network models to track the spatial dynamics of ES flows (ESFs) and the interactions between ecosystems and socio-economic systems within the basin on an annual scale from 2000 to 2020. The results highlight cross-scale impacts and feedback processes between local subbasins and the larger regional basin: As the supply-demand ratios of freshwater ESs, soil conservation ESs, and food ESs increase within individual subbasins of the YRB, more surplus ESs flow among subbasins. This not only alleviates spatial mismatches in ES supply and demand across the entire basin but also enhances the connectivity of the basin's ESF network. Subsequently, the cascading transfer and accumulation of ESs feedback into local socio-ecological interactions, with both socio-economic factors and the capacity for ES output within subbasins becoming increasingly reliant on external ES inflows. These results underscore the crucial role of ESFs within the CHANS of the YRB and imply the importance of cross-regional cooperation and cross-scale management strategies in optimizing ES supply-demand relationships. Furthermore, this study identifies the potential risks and challenges inherent in highly coupled systems. In conclusion, this work deepens the understanding of the spatial flow characteristics of ESs and their socio-ecological interactions; the analytical methods used in this study can also be applied to research on large river basins like the YRB, and even larger regional ecosystems.

Spatiotemporal pattern and obstacle factors of coupling relationship between habitat quality and urbanization level in the Yellow River Basin, China

Land use change stands as the primary factor influencing habitat quality (HQ). Clarifying the spatiotemporal change and the obstacle factors of the coupling relationship between HQ and urbanization level (UL) can provide imperative references for achieving sustainability in the Yellow River Basin (YRB). This study is based on the InVEST model, spatial autocorrelation, and obstacle factor analysis to measure the spatiotemporal dynamics and impediments of the coupling relationship between HQ and UL from 2000 to 2020 in the YRB. The findings were as follows: (1) From 2000 to 2020, the HQ showed a tendency of rise first and then fall, with the pattern of "High in the middle and west, low in the east"; (2) from 2000 to 2020, the UL had an upward trend, with the pattern of "Low in the west, high in the middle and east"; (3) the coupling and coordination level of HQ and UL in the YRB changed from extreme incoordination to verge of coordination, and it had a distribution pattern of "High in the east, low in the west", with the high-value area expanding to the east and the low-value area shrinking to the west. (4) Location condition, climate, proportion of construction land, vegetation index, and proportion of non-agricultural employment are the main obstacle factors that determined the coupling and coordination of the HQ and UL.

Achieving higher eco-efficiency for three staple food crops with ecosystem services based on regional heterogeneity in China

Farmland ecosystems can provide both economic products and ecosystem services that are important in maintaining food security and ecological safety. However, the ecological functions of farmland ecosystems have not been adequately evaluated in China, especially from the perspective of ecological efficiency for three staple food crops (wheat, maize and rice). Moreover, the contribution of ecosystem services value (ESV) to agricultural eco-efficiency (AEE), and the factors that influence AEE for the three staple food crops in different regions are still unclear. In this study, data envelopment analysis (DEA) was applied to calculate the AEE using group-frontier and meta-frontier methods based on regional heterogeneity. We measured AEE for wheat, maize and rice production with and without ESV and compared the gap between ecological inefficiency resulting from management inefficiency and technology gap inefficiency. The research results showed that, first, the involvement of ESV could effectively promote AEE. In particular, water conservation, soil conservation and the nutrient cycle contributed to the promotion of eco-efficiency. The mean ΔAEE (the difference in AEE with or without ESV) of wheat, maize and rice increased by 15 %, 10 % and 13 % with group-frontier and by 20 %, 10 % and 11 % with meta-frontier, respectively. Second, the improvement of AEE was higher in ecologically sensitive areas than that in other areas, especially for wheat and rice. Third, although the involvement of ESV reduced ecological inefficiency, specifically for management inefficiency, its contribution differed significantly across regions. We provide suggestions on improving AEE and reducing inter-regional differences in China. In brief, these findings suggest that, except for grain yields, ecosystem services need to be recognized in the production of three staple food crops, especially in ecologically sensitive areas. This is helpful for crop planning and planting division in terms of sustainable development.

Assessing the responses of ecosystem patterns, structures and functions to drought under climate change in the Yellow River Basin, China

Understanding how ecosystems respond and adapt to drought has become an urgent issue as drought stress intensifies under climate change, yet this topic is not fully understood. Currently, conclusions on the response of ecosystems in different regions to drought disturbance are inconsistent. Based on long MODIS data and observed data, this study systematically explored the relationships between ecosystem patterns, structures and functions and drought, taking a typical climate change-sensitive area and an ecologically fragile area-the Yellow River Basin-as a case study. Drought assessment results revealed that the Yellow River Basin has experienced meteorological and hydrological drought during most of the last two decades, predominantly characterized by medium and slight droughts. The ecosystem patterns and structures changed dramatically as the grassland decreased and the landscape fragmentation index (F) increased with increasing wetness. The annual gross primary productivity (GPP) increased, the water use efficiency (WUE) declined and ecosystem service value (ESV) exhibited a W-shaped increase at the watershed scale, but there were significant regional differences. There were positive correlations between F, GPP, ESV and drought indices, while there was a negative correlation between WUE and drought indices at the watershed scale. Under drought stress, the ecosystem structure in the basin was disrupted, the GPP and ESV decreased, but the WUE increased. Notably, approximately 106 %, 20 %, and 1 % of the maximum reductions in F, GPP, and ESV, respectively, were caused by drought, while the maximum 4 % of WUE increased. Responses of some functions in the wetland and grassland to drought vary from those in other ecosystems. The mechanisms underlying ecosystem responses to drought were further investigated. This study enhances the understanding of these responses and will help stakeholders formulate drought mitigation policies and protect ecosystem health.

Coupling coordination analysis and key factors between urbanization and water resources in ecologically fragile areas: a case study of the Yellow River Basin, China

The rapid urbanization (UR) and industrialization in the Yellow River Basin (YRB) have resulted in a significant scarcity of water resources (WRs), highlighting the need to investigate the complex and dynamic relationship between UR and WR for sustainable urban development in ecologically fragile areas. This study utilizes the coupling coordination degree model (CCDM), spatial correlation analysis, and Tobit model to examine the coupling coordination relationship, spatial effects, and key factors between UR and WR in sixty prefecture-level cities within the YRB. The empirical findings reveal that the development of the WR subsystem lags behind the UR subsystem and that there is a significant spatial disequilibrium in the CCD between UR and WR. Specifically, the high-high clusters are located in the northwest and east, while the low-low clusters are spread in the southwest. Furthermore, investment in science and technology and economic development have a positive impact on the CCD, while government capacity, urban construction, and industrial structure have a negative impact. These results can provide valuable guidance for decision-making in urban planning for ecologically fragile areas facing water supply constraints.

Spatial Responses of Ecosystem Service Trade-offs and Synergies to Impact Factors in Liaoning Province

Global ecosystem services (ESs) are experiencing a significant decline, necessitating the development of robust environmental governance policies. To address the lack of integrated planning with heavy industry as the research object and a lack of knowledge of ES trade-offs and synergies in China's ecological and environmental governance. In this study, the spatial and temporal variations of four ESs (water yield (WY), soil conservation (SC), carbon storage (CS), and habitat quality (HQ)) were determined in the study area of Liaoning Province. Explore the mechanisms that shape ecosystem service trade-offs and synergies and the factors that influence them. Spearman's correlation and difference analyses were proposed to determine the spatial and temporal distributions of trade-offs and synergistic relationships among ESs. In addition, we constructed a multiscale geo-weighted regression (MGWR) model to investigate driver spatial heterogeneity affecting trade-offs and synergies. The results revealed that (1) In the study area, ESs were on the rise in Liaoning Province. (2) Temporally, ESs were overwhelmingly dominated by synergies; at the spatial scale, ESs were dominated by trade-offs of varying degrees, with the area of synergy between WY and SC being the highest. (3) ESs demonstrated spatial heterogeneity in intensity and were more impacted by natural factors such as vegetation cover, elevation, and precipitation than by characteristics related to human activity. This study helps improve understanding of the interactions and dependencies among ESs and can provide a reference for ecological governance and improvements in Liaoning Province.

Responses of Soil Microbial Survival Strategies and Functional Changes to Wet-Dry Cycle Events

Soil microbial taxa have different functional ecological characteristics that influence the direction and intensity of plant-soil feedback responses to changes in the soil environment. However, the responses of soil microbial survival strategies to wet and dry events are poorly understood. In this study, soil physicochemical properties, enzyme activity, and high-throughput sequencing results were comprehensively anal0079zed in the irrigated cropland ecological zone of the northern plains of the Yellow River floodplain of China, where Oryza sativa was grown for a long period of time, converted to Zea mays after a year, and then Glycine max was planted. The results showed that different plant cultivations in a paddy-dryland rotation system affected soil physicochemical properties and enzyme activity, and G. max field cultivation resulted in higher total carbon, total nitrogen, soil total organic carbon, and available nitrogen content while significantly increasing α-glucosidase, β-glucosidase, and alkaline phosphatase activities in the soil. In addition, crop rotation altered the r/K-strategist bacteria, and the soil environment was the main factor affecting the community structure of r/K-strategist bacteria. The co-occurrence network revealed the inter-relationship between r/K-strategist bacteria and fungi, and with the succession of land rotation, the G. max sample plot exhibited more stable network relationships. Random forest analysis further indicated the importance of soil electrical conductivity, total carbon, total nitrogen, soil total organic carbon, available nitrogen, and α-glucosidase in the composition of soil microbial communities under wet-dry events and revealed significant correlations with r/K-strategist bacteria. Based on the functional predictions of microorganisms, wet-dry conversion altered the functions of bacteria and fungi and led to a more significant correlation between soil nutrient cycling taxa and environmental changes. This study contributes to a deeper understanding of microbial functional groups while helping to further our understanding of the potential functions of soil microbial functional groups in soil ecosystems.

Ecosystem services relationship characteristics of the degraded alpine shrub meadow on the Qinghai-Tibetan Plateau

Alpine shrub meadows hold significant importance as grassland ecosystems on the Qinghai-Tibetan Plateau (QTP). They provide a range of vital ecosystem services (ESs) and are commonly utilized as summer pastures by herders, resulting in short grazing periods and high grazing intensities. Unfortunately, these practices have led to varying degrees of degradation, thereby affecting the sustainable provision of ESs. However, the current knowledge regarding changes in ESs and their characteristics under the influence of degradation, particularly the differences between alpine shrub and alpine meadow ecosystems, is insufficient. To address this gap, this study aimed to investigate and analyse changes in four ESs within alpine shrub meadows across different levels of degradation, as well as explore their relationships. The research was conducted in a summer pasture located in the northeastern QTP. The findings revealed a substantial reduction of 85.9% in forage supply due to degradation in alpine shrub meadows. Moreover, regulating services experienced a decline followed by an increase in instances of heavy degradation. Trade-offs were observed between provisioning and regulating services, while synergistic relationships were identified among different regulating services. Degradation exacerbated imbalances between provisioning and regulating services, whereas light degradation allowed for a better equilibrium between the two. Comparatively, alpine meadows exhibited higher levels of forage supply and carbon storage services, whereas alpine shrub ecosystems displayed greater nutrient supply and water retention services. It was observed that changes in ESs and relationship patterns within alpine shrub meadows were significantly influenced by the presence of alpine meadows. Consequently, safeguarding the structural integrity of alpine meadows and addressing conflicts over ESs is essential to ensure coordination and sustainability of ESs within alpine shrub meadows. The outcomes of this study provide valuable insights for ecosystem management and ecological restoration initiatives in alpine shrub meadows on the QTP.

Spatiotemporal exploration of ecosystem service, urbanization, and their interactive coercing relationship in the Yellow River Basin over the past 40 years

Understanding how ecosystem services (ESs) interact with urbanization is crucial for formulating sustainable development policies. Although previous literature has paid attention to this topic, information on complex spatiotemporal interactions between ESs and urbanization remains inadequate, especially in the Yellow River Basin (YRB), a typical basin that will usher in rapid progress of ecological protection and urbanization. In this study, we constructed a framework for evaluating ecosystem service values (ESV) and urbanization by synthesizing multi-source data in the YRB from 1980 to 2018, and further revealing the interactive coercing mechanisms of ESV and urbanization. We found that the YRB has experienced rapid urbanization, with an increasing growth trend for all urbanization indicators, especially from 2000 onwards. ESV had a significant negative correlation with urbanization, showing a decreasing trend with urbanization growth before 2000, but reversed this trend after 2000 as ecological restoration projects offset the adverse effects of urbanization on ESV. Furthermore, while significant negative spatial correlations occurred between ESV and urbanization, these correlations diminished over time. The results also revealed differences in the spatial correlations between global and local scales, with three types of spatial correlations at the local scale: High-Low (high ESV and low urbanization), Low-High (low ESV and high urbanization), and Low-Low (low ESV and low urbanization). Our results contribute to understanding the interactive coercing relationship between ESV and urbanization in the YRB, particularly at the local scale, and insights into coordinating future ecological protection and urban development.

The potential for carbon sequestration by afforestation can be limited in dryland river basins under the pressure of high human activity

Dryland regions cover >40 % of the Earth's land surface. Both human activities and climate change have driven forest expansion in parts of dryland regions. Afforestation has been implemented widely to enhance carbon sequestration and benefit the ecological environment of many global drylands. However, the potential and available afforestation space in drylands is uncertain due to the conflicts between additional forest areas and available water. How afforestation will affect the potential for forest carbon stock is also unclear. This paper assessed the future spatial distribution of afforestation and potential forest carbon stock in a typical dryland region, the Yellow River Basin (YRB), which has experienced rapid afforestation and high human activity pressure over the past several decades. Combining the future land use change model (FLUS) and local important development planning, we simulated future afforestation distributions and estimated potential forest carbon stock under the ecological restoration, urban expansion, and cultivated land protection scenarios. The afforestation carbon stock was predicted by considering the dynamic change trends of the mature forest, the immature forest, and new afforestation. The results demonstrated that the potential afforestation area would be limited to 4000 km² in the YRB accounting for less than one-twentieth of the total forest area. Accordingly, the maximum potential forest carbon stock would increase only 59.5 × 10⁶ t. These findings implies that afforestation programs in drylands should further consider the optimum allocation of afforestation space and the balance between carbon and water in drylands, especially under a changing climate with increasing human activities.

Spatio-Temporal Characteristics of Trade-Offs and Synergies in Ecosystem Services at Watershed and Landscape Scales: A Case Analysis of the Yellow River Basin (Henan Section)

The changes and interrelationships of ecosystem services at different global and regional scales have been actively investigated. Clarifying the trade-offs and synergies between ecosystem services from a multi-scale scientific perspective is vital to improve the coordinated and sustainable development of the watershed and ecological protection. As an important ecological barrier region of the Yellow River Basin, the Henan section provides a variety of important ecosystem services. This study analyzes the characteristics of land use changes in the Yellow River Basin (Henan section) from 1990 to 2020. Based on the InVEST model, four ecosystem services-water production, soil conservation, carbon storage and food supply have been evaluated. The Spearman correlation coefficient was used to further reveal the spatial and temporal characteristics of the trade-offs and synergies at different levels of each service. The results showed that: (1) From 1990 to 2020, the basin was dominated by farmland conservation. The construction land area mainly exhibited an inflow behavior, while other land use types were mainly related to outflow. (2) From 1990 to 2020, the water yield, soil conservation and carbon storage first increased and then decreased, while food supply gradually increased. The spatial distribution of these ecosystem services was lower in the southwest and slightly higher in the northeast and farmland had the highest capacity of water production and food supply, while woodland had the highest capacity for soil conservation and carbon storage. (3) The Spearman rank correlation coefficient indicated that the trade-offs for the ecosystem services in the Yellow River Basin (Henan section) dominated before 2000, and the synergies gradually strengthened after 2000. (4) There were clear spatial heterogeneities in the ecosystem services of the basin; for instance, the functions in the middle and lower reaches of the Yellow River Basin (Henan section) were mainly trade-offs, while the higher elevations in the middle reaches exhibited synergistic relationships. This study aims to clarify the trade-offs and synergies between ecosystem services at the different levels. Based on our findings, countermeasures and suggestions for ecological protection and management are proposed to promote the coordinated development of social economy and ecological protection.

Inter-regional ecological compensation in the Yellow River Basin based on the value of ecosystem services

Ecological compensation in the Yellow River Basin aims to improve its ecological and environmental management capacity. Based on data on land-use changes in the Yellow River Basin from 2010 to 2020, this study used the equivalent factor method to assess the value of ecosystem services in the basin. This was measured at three spatial scales in the upper, middle, and lower reaches, encompassing; nine provinces and 72 cities. The priority and amount of ecological compensation were determined for the Yellow River Basin regions. Results show that (1) The total value of ecosystem services in the Yellow River Basin increased from 1798.317 billion yuan in 2010 to 1838.259 billion yuan in 2020. Grasslands had the highest total ecosystem service value in 2020, accounting for 46.11%. (2) The value of ecosystem services in the Yellow River Basin region is upstream > midstream > downstream. Qinghai Province has the highest value of ecosystem services among the nine provinces, and the level of economic development in each region is inversely correlated with the value of ecosystem services. (3) The ecosystem service value and the economic development level of the cities in the Yellow River Basin are positively and negatively correlated with the priority of ecological compensation, respectively. Among them, the cities in the upper reaches are the most urgent targets for national ecological compensation. (4) The total ecological compensation in the Yellow River Basin in 2020 was approximately 122.63 billion yuan. Further, the amount of vertical ecological compensation to be paid by the state was approximately 114.673 billion yuan, and the horizontal compensation to be borne between provinces was approximately 7.957 billion yuan. The findings of this study provide novel insights into improving ecological compensation in the Yellow River Basin regions.

Review on Eco-Environment Research in the Yellow River Basin: A Bibliometric Perspective

The Yellow River Basin (YRB) is an important economic zone and ecological barrier in China. The analysis of its research characteristics and hotspots has been helpful to grasping the future research direction. This work carried out text mining and analysis on scientific papers related to eco-environment research in the YRB from English and Chinese publications. It showed that: there was a fluctuating upward trend over the past 30 years, which was closely related to major events in the YRB during the same period. Chinese research institutions have a closer cooperation with the USA, Australia and other developed countries. More articles were from high-quality journals in ecology, the environment, and others. Interestingly, research institutions with more Chinese articles were mainly located around Beijing or the YRB. Additionally, from a research object perspective, both the English and Chinese articles have mainly focused on large areas such as the lower Yellow River, the middle reaches of the Yellow River, and the upper reaches of the Yellow River, then turning to small areas such as the Yellow River estuary and the source area of the Yellow River. Eco-environment research in the YRB has involved multiple disciplines, and "water-soil-vegetation-ecological protection" has been widely concerned. From the evolution law of hot topics, it has shown a transformation from quantity to quality, from utilization to management, from macro to micro, from construction to high-quality development. It suggests that future research should focus on water, soil, the ecological environment and local high-quality development in small regions and small watersheds.

Analysis of ecosystem service drivers based on interpretive machine learning: a case study of Zhejiang Province, China

A systematic understanding of the driving mechanisms of ecosystem services (ESs) and the relationships among them is critical for successful ecosystem management. However, the impact of driving factors on the relationships between ESs and the formation of ecosystem service bundles (ESBs) remains unclear. To address this gap, we developed a modeling process that used random forest (RF) to model the ESs and ESBs of Zhejiang Province, China, in regression and classification mode, respectively, and the Shapley Additive Explanations (SHAP) method to interpret the underlying driving forces. We first mapped the spatial distribution of seven ESs in Zhejiang Province at a 1 × 1 km spatial resolution and then used the K-means clustering algorithm to obtain four ESBs. Combining the RF models with SHAP analysis, the results showed that each ES had key driving factors, and the relationships of synergy and trade-off between ESs were determined by the driving direction and intensity of the key factors. The driving factors affect the relationships of ESs and consequently affect the formation of ESBs. Thus, managing the dominant drivers is key to improving the supply capacity of ESs.

Natural and anthropogenic forces on suspended sediment dynamics in Asian estuaries

Climate change and anthropogenic activities are affecting the hydrological conditions of rivers and may have altered nutrient and suspended sediments released into coastal seas. However, testing this hypothesis is difficult, confounded by the lack of observational data and the unavailability of globally accepted suspended sediment concentration (SSC) algorithms. Here, we analyzed the trends in SSC (2000-2020) at the mouths of 10 major Asian rivers using 10 available satellite-SSC algorithms. We identified spatially distinct trends, with SSC decreasing at the mouths of the Yellow, Pearl, and Indus rivers, and increasing trends at the mouths of the Narmada and Ganges-Brahmaputra rivers, while there were no significant trends at the mouths of the remaining rivers. River discharge, dams, and land use changes in basins individually did not suffice, but reproduced the observed SSC trends when used together. Our results imply that anthropogenic activities threaten the marine ecosystem more than climate forcing on Asian coasts.

Influencing factors of the supply-demand relationships of carbon sequestration and grain provision in China: Does land use matter the most?

The provision of ecosystem services (ESs) such as carbon sequestration and grain provision are critical components to sustainable development. Reaching carbon neutrality generally requires the growing carbon sequestration of forest land, and feeding a growing population needs an expansion of cultivated land. However, limited land resources may lead to a contradiction between the carbon sequestration and grain provision. China has proposed long-term and large-scale land use programs, and exploring whether these land use policies are effective for ES sustainable provision would be instructive for future policy implications. This study integrated multi-source data in the socioecological dimension to determine the extent by which land use and land use change influence the supply-demand mismatches of carbon (carbon sequestration and emission) and grain (grain provision and consumption) in China at the provincial level. The result showed that the total quantity of carbon emissions surpassed carbon sequestration and the grain provision could cover the consumption from 2000 to 2015. Spatially, southeastern coastal provinces had higher grain deficits and northeast provinces had higher carbon deficits. This study further detected the influencing factors of the mismatches between the supply and demand of the two ESs. Excluding land use factors, our results showed that social factors contributed 38% and 47% to the supply-demand mismatches of carbon and grain, respectively, and natural factors contributed 39% and 15%, respectively. During 2000-2005, 2005-2010, and 2010-2015, cropland changes significantly affected grain balance, while forest land changes did not significantly affect carbon balance. These results indicated that cropland protections are vital to food safety, and carbon emission reductions should be the focus for carbon balance. Finally, this study makes policy suggestions for land use and ecosystem management, and a future research framework was proposed to help mitigate ES supply-demand imbalance.

Evaluating Ecosystem Services and Trade-Offs Based on Land-Use Simulation: A Case Study in the Farming–Pastoral Ecotone of Northern China

Evaluating the impacts of land-use change (LUC) on ecosystem services (ESs) is necessary for regional sustainable development, especially for the farming–pastoral ecotone of northern China (FPENC), an ecologically sensitive and fragile region. This study aimed to assess the impacts of LUC on the ESs and provide valuable information for regional planning and management in the FPENC. To accomplish this, we assessed LUC in the FPENC from 2010 to 2020 and simulated land-use patterns in 2030 under three plausible scenarios: the business as usual scenario (BAUS), economic development scenario (EDS), and ecological protection scenario (EPS). Then, we quantified five ESs (including crop production, water yield, soil retention, water purification, and carbon storage) for 2020–2030 and analyzed the trade-offs and synergies among ESs in all scenarios. The results show that FPENC experienced expanding farming land and built-up land throughout 2010–2020. Under the BAUS and EDS from 2000 to 2030, especially EDS, the increase in farming land and built-up land will continue. As a result, crop production and water yield will increase, while soil retention, water purification, and carbon storage will decrease. In contrast, EPS will increase soil retention, water purification, and carbon storage at the cost of a decline in crop production and water yield. These results can provide effective reference information for future regional planning and management in the farming–pastoral ecotone.

Letter to the editor regarding Li et al. (2022) Identifying ecosystem service bundles and the spatiotemporal characteristics of trade-offs and synergies in coal mining areas with a high groundwater table, Liu et al. (2021) Ecosystem service multifunctionality assessment and coupling coordination analysis with land use and land cover change in China's coastal zones, and Zhang et al. (2021) Spatial relationships between ecosystem services and socioecological drivers across a large-scale region: A case study in the Yellow River Basin

Three studies used empirical equations to calculate the rainfall erosivity factor R, and all three equations appeared to be incorrect. All of the studies were published in the journal Science of the Total Environment, and none of them accurately cited the sources of the incorrect equations that were used in them. We were able to track down the original equation as well as the source of the equation. Additionally, it was discovered that the original equation contained an incorrect conversion factor, which needs to be corrected.

Spatial correlation among cultivated land intensive use and carbon emission efficiency: A case study in the Yellow River Basin, China

Considering the current global goal of carbon neutrality, the relationship between cultivated land intensive use (CLIU) and carbon emission efficiency (CEE) should be explored to address the global climate crisis and move toward a low-carbon future. However, previous work in this has been conducted at provincial/regional scales and few have identified the spatial correlation between CLIU and CEE at the scale of large river basins. Therefore, this study explored the spatiotemporal characteristics of CLIU, cultivated land carbon emissions (CLCE), and CEE, as well as the spatial correlation between CLIU and CEE in the Yellow River Basin (YRB), China. A comprehensive evaluation model, the Intergovernmental Panel on Climate Change (IPCC) coefficient methodology, existing data envelopment analysis model, and bivariate spatial autocorrelation models were used to analyze statistical data from 2005 to 2017. We found that the overall CLIU and CLCE values in the YRB exhibited a continuous increase; the average carbon emission total efficiency and carbon emission scale efficiency first decreased and then increased, and the average carbon emission pure technical efficiency gradually decreased. Areas of high CLCE were concentrated in eastern areas of the YRB, whereas those of high CLIU, carbon emission total efficiency, carbon emission scale efficiency, and carbon emission pure technical efficiency predominantly appeared in the eastern areas, followed by central and western areas of the YRB. Spatial analysis revealed a significant spatial dependence of CLIU on CEE. From a global perspective, the spatial correlations between CLIU and CEE changed from positive to negative with time. Moreover, the aggregation degree between CLIU and CEE gradually decreases with time, while the dispersion degree increases with time, and the spatial correlation gradually weakens. The local spatial autocorrelation further demonstrates that the number of high-low and low-high clusters between CLIU and CEE gradually increases over time, while the number of high-high and low-low clusters gradually decreased over time. Collectively, these findings can help policymakers formulate feasible low-carbon and efficient CLIU policies to promote win-win cooperation among regions.

Spillover Effects of Built-Up Land Expansion Under Ecological Security Constraint at Multiple Spatial Scales

Land-use change is a global issue, and the built-up land expansion has affected the ecological landscape patterns of the major river basins in the world. However, measurement of the ecological risks of potential landscape and identification of the dynamic relationships by natural and human-driven built-up land expansion at different zoning scales are still less understood. Based on multi-period Landsat satellite image data, we combined remote sensing (RS) and geography information systems (GIS) technologies with Spatial Durbin Panel Model to quantitatively analyze the landscape ecological effects under the built-up land expansion in the Yellow River Basin. The results showed that there is spatial heterogeneity in the built-up land expansion and ecological security patterns, with the expansion gravity center gradually spreading from the downstream to the middle and upstream areas, and the most dramatic change in landscape patches of ecological safety patterns occurring around the year 2000. At different zoning scales, there is a spatial spillover effect on the interaction between built-up land expansion and ecological security, with the significance of the regression estimates decreasing from large sample sizes to small sample sizes. Our findings highlighted the importance of spatial heterogeneity at different zoning scales in identifying the dynamic relationship between built-up land expansion and ecological security, scientific planning of land resources, and mitigation of ecological and environmental crises.

Identification of Coupling Relationship between Ecosystem Services and Urbanization for Supporting Ecological Management: A Case Study on Areas along the Yellow River of Henan Province

Urbanization has an important effect on ecosystem services (ESs) and identifying the relationship between urbanization and ESs can provide a decision-making reference for regional ecological protection and management. Taking the areas along the Yellow River of Henan Province (AYRHP) as a research area, a coupling system of ESs and urbanization is established in this study to reveal the coupling relationship between the two. ESs are estimated by using Carnegie–Ames–Stanford approach, revision universal soil loss equation, and Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) models. The urbanization level is evaluated from three dimensions, namely, population, economy, and land. The coupling coordination relationship between various ESs and urbanization in AYRHP is quantified from 2000 to 2018 on the county scale based on the coupling coordination degree (CCD) model. The lead–lag relationship between ESs and urbanization is identified by using the relative development degree model, and ecological management zoning is conducted. Results show that in the study period, net primary production (NPP), soil conservation, and food production are increased, whereas water yield is decreased. In the study period, population, economy, and land urbanization level are increasing, and the comprehensive urbanization level is increased by 51.63%. The total CCD between NPP, food production, and water yield and comprehensive urbanization is basic or moderate coordination, whereas that between soil conservation and comprehensive urbanization is moderate maladjustment. In the research period, the coupling coordination between NPP and food production and comprehensive urbanization is increasing; that between water yield and comprehensive urbanization is fluctuated; and that between soil conservation and comprehensive urbanization is decreasing. The result of the research into the relative development degree in 2018 showed that food production, water yield, and soil conservation lag behind the urbanization level in most regions and counties along the Yellow River of Henan Province. On the basis of the lead–lag relationship between different ESs and urbanization level, the AYRHP are divided into ecological reconstruction area, ecological and agricultural improvement area, and ecological conservation area. CCD and relative development degree models can be used to evaluate the coordination relationship between ESs and urbanization, which provides scientific support for regional ES management.

Assessing Changes in the Value of Forest Ecosystem Services in Response to Climate Change in China

Ecosystem services are the basis of human survival and development and play an irreplaceable role in maintaining the dynamic balance of the earth’s life support system and environment. This study evaluated the annual forest ecosystem service values (ESVs) and their spatial evolution characteristics from 2001 to 2020 in China and revealed the impact of climatic factors as well. The equivalent factor method was applied to calculate ESVs in combination with net primary productivity (NPP) calculated by the CASA model. The water conservation results based on the InVEST model and equivalent factor method were compared to test the reliability of the method. From 2001 to 2020, the annual forest ESVs ranged from RMB 9.17 trillion to 10.81 trillion, with an average of RMB 9.99 trillion in China. The forest ESVs increased from the northwest to the southeast regions of China with the lowest values of less than RMB 3 million per square kilometer and relatively high values of more than RMB 9 million per square kilometer. In the past 20 years, the forest ESVs have shown a significant increasing trend, especially in the Northeast Forest Region and Southeast Forest Region. The ESVs have decreased only in very few forest areas such as Cuona and Motuo counties on the southern edge of Tibet Province in Southwest China and Pingtung and Kaohsiung counties in southern Taiwan. The mean annual forest ESV was necessarily higher in the recent 10 years (2011–2020, RMB 10.43 trillion) than in the previous 10 years (2001–2010, RMB 9.55 trillion), while the spatial growth rate was usually less than 20%. The annual forest ESVs were significantly correlated with temperature, precipitation and evapotranspiration but not with sunshine hours and relative humidity across the 20 years. In most areas (>60%), the positive impact of various climatic factors was dominant, and the area positively affected by precipitation was the largest (76%). The mean annual forest water conservation from 2001 to 2020 was RMB 1.46 trillion based on the InVEST model and was RMB 1.77 trillion based on the equivalent factor method. Overall, the results obtained by the two methods are roughly equal and mostly spatially matched. This study has some guiding significance for utilizing resources rationally, strengthening ecological environment protection and improving adaptability to climate change.

Analyzing the Interrelationships among Various Ecosystem Services from the Perspective of Ecosystem Service Bundles in Shenyang, China

An understanding of the relationships among multiple ecosystem services (ES) facilitates ecosystem management and decision-making. The study of ES bundles can well explain the complex interactions between different ES in a region. Shenyang is a significant economic development and food production area in Northeast China, with a diverse range of ES types. In this study, we quantified eleven ES from Shenyang, China (two provisioning services, eight regulating services, and one cultural service). The trade-offs and synergies among ES were analyzed by Spearman’s correlation analysis. The ES bundles were identified using principal component analysis and k-means cluster analysis. Finally, the random forest method was employed to identify the driving factors affecting the ES bundles. The results showed: (1) all ES in Shenyang improved between 2000 and 2019; (2) the most obvious trade-off was found between sand fixation and water conservation; (3) the ES in the study region could be clustered into five different ES bundles which were primarily affected by land-use type; and (4) social-ecological factors largely explained and predicted the formation and distribution of ES bundles. The study provides reference information for the management and optimization of Shenyang’s ecosystems and land use regulation.

Assessment of Grassland Ecosystem Service Value in Response to Climate Change in China

The assessment of ecosystem services provides an intuitive source of information on the benefits humans derive from ecosystems. The equivalent factor method was applied to calculate the ecosystem service value (ESV) in combination with net primary productivity (NPP) calculated by the process-based Carnegie–Ames–Stanford approach (CASA) model. This study evaluated grassland ESV and its spatial evolution characteristics in China from 2001 to 2020 and revealed the impact of climate factors. For 2001–2020, the annual grassland ESV ranged from 1.17 × 1012 to 1.51 × 1012 yuan (renminbi, China yuan—the same below; $0.15 × 1012–$0.20 × 1012, US dollar), with an average of 1.37 × 1012 yuan ($0.18 × 1012). The spatial pattern of ESV per unit area of grassland was notably characterized by an increase from northwest to southeast. However, the value of grassland ecosystem services was relatively large (exceeding 10 × 106 yuan; $1.30 × 106) in northern and western provinces and was the lowest (less than 0.2 × 106 yuan; $0.03 × 106) in eastern and southern provinces. In the last 20 years, grassland ESV has increased in most areas of China and has decreased only in some western and northern areas. Compared with the first 10 years, the average ESV of grassland in most areas increased in the last 10 years, usually by less than 20%. However, it decreased in the western and northern parts of China, mainly concentrated in the alpine meadow and alpine grassland of the Qinghai–Tibet Plateau and the grassland around the Yili region of Xinjiang. Precipitation was the main regulating factor of grassland ESV and had a positive impact in 79% grassland areas, especially in northern China. Evapotranspiration and sunshine hours exhibited a marginal impact on ESV, but temperature and relative humidity had no significant effect. Overall, this study contributes to exploring the spatiotemporal patterns of grassland ecosystem service value and the impact of climate factors in China, thereby providing reliable guidance for grassland ecosystem management.

Evaluation of Regional Water Resources Management Performance and Analysis of the Influencing Factors: A Case Study in China

Water resources management (WRM) is a global strategic issue. Effectively evaluating WRM performance and analyzing its influencing factors have strong practical significance for improving regional WRM performance. Data envelopment analysis (DEA) is one of the most popular models to measure the efficiency of decision-making units (DMUs). Taking regional WRM performance as efficiency DMUs, this paper proposes the indicator system to quantify WRM performance from the perspectives of resource endowments, economic and technological development, and ecosystem protection. The WRM performance of 31 provincial administrative regions in mainland China from 2013 to 2019 are measured, and the temporal and spatial changes are explored using the window DEA model and the Malmquist index model. Finally, the Tobit model is used to quantitatively analyze the affecting factors. The results indicate that: (1) in 2015 and 2019, WRM performance of Sichuan, Shaanxi, Xinjiang, Inner Mongolia, and Guangxi were slightly higher than that in other years, and the areas with more room for WRM performance improvements were areas with abundant water resources; (2) from 2013 to 2019, China’s overall WRM performance showed a slow rise, and there were obvious fluctuations in 2018; (3) the improvement in WRM performance was primarily the result of an improvement to comprehensive technical efficiency changes (EC), whereas technological progress changes (TC) have largely restricted China’s WRM performance; (4) the main influencing factors of WRM performance in China were as follows: industrial development level, water resources utilization rate, and urban sewage discharge per capita.

Land Use and Land Cover Change in the Yellow River Basin from 1980 to 2015 and Its Impact on the Ecosystem Services

Land use and land cover change is an important driving force for changes in ecosystem services. We defined several important human-induced land cover change processes such as Ecological Restoration Project, Cropland Expansion, Land Degradation, and Urbanization by the land use/land cover transition matrix method. We studied human-induced land cover changes in the Yellow River Basin from 1980 to 2015 and evaluated its impact on ecosystem service values by the benefit transfer method and elasticity coefficient. The results show that the cumulative area of human-induced land cover change reaches 65.71 million ha from 1980 to 2015, which is close to the total area of the Yellow River Basin. Before 2000, Ecological Restoration Project was the most important human-induced land cover change process. However, due to the large amount of cropland expansion and land degradation, the area of natural vegetation was reduced and the ecosystem value declined. Since 2000, due to the implementation of the “Grain for Green” program, the natural vegetation of upstream area and midstream area of Yellow River Basin has been significantly improved. This implies that under an appropriate policy framework, a small amount of human-induced land cover change can also improve ecosystem services significantly.

Coupling Coordination Relationship and Driving Mechanism between Urbanization and Ecosystem Service Value in Large Regions: A Case Study of Urban Agglomeration in Yellow River Basin, China

Mastering the coupling and coordination relationship and driving mechanism of urbanization and ecosystem service value (ESV) is of great significance to ecological protection and regional sustainable development. In this paper, the coupling coordination model, geographic detector and GWR model are used to analyze the spatio-temporal coupling interaction between urbanization and ESV and the spatial differentiation characteristics of influencing factors from 1995 to 2018. The results of the study are as follows: (1) During the study period, cities in the Yellow River Basin experienced accelerated urban expansion, and the ESV of forests, water and wetlands increased, which offset the reduction in ESV due to the expansion of construction land and farmland and grassland. (2) The degree of coupling and coordination between the two gradually improved, but the overall situation showed a low-level coupling and coordination process. Mild coupling coordination gradually increased, reaching an increase of 38.10%; severe imbalance types tended to disappear, decreasing by 52.38%, and coupling subtypes developed from lagging urbanization to ESV backward types. The high-value areas of the coupling coordination degree are distributed in the high-value areas of ESV in the north of the upper reaches, and the low-value areas are distributed in the cities of Henan and Shandong with high urbanization levels in the downstream and most resource-based cities in the middle reaches. (3) In addition, the spatial intensity of the effect of each dominant factor on the degree of coupling coordination is different. Economic growth, technological development, environmental regulations and the proportion of forest land have positive and belt-shaped alienation characteristics for the coupling and coordination of the two, and infrastructure and temperature show negative driving characteristics. Therefore, the coupling and coordination relationship between ESV and urbanization should be clarified to help future urban planning. On the basis of determining the regional environmental carrying capacity and the adjustment direction of the rational planning of land resources, the impact of urban barriers formed by administrative boundaries and natural geographical conditions on the development of urban agglomerations should be broken to achieve the overall high-quality and coordinated development of the basin.

Green Transition of Cultivated Land Use in the Yellow River Basin: A Perspective of Green Utilization Efficiency Evaluation

Exploring the green transition of cultivated land use from the perspective of green utilization efficiency evaluation has become an important content of deepening the study of cultivated land use transition, which is of great significance to promote food security and ecological civilization construction. At present, there are few studies on the green utilization efficiency of cultivated land (GUECL), which covers the comprehensive benefits of economy, ecology and society, combined with the requirements of ecological civilization and green development. Taking 65 cities (regions and autonomous prefectures) of the Yellow River Basin as the basic evaluation unit, the GUECL of the Yellow River Basin is evaluated with a Super-SBM model. In general, the GUECL of the Yellow River Basin was not high at four time points of 2000, 2006, 2012 and 2018, which presents a trend of “rising first and then falling”. Analyzing its temporal and spatial evolution pattern, the GUECL in the upper, middle and lower reaches presented an order of the upper reaches area > the lower reaches area > the middle reaches area; and the spatial variation trend showed a decrease from west to east, and a U-shaped change in the south-north direction. Using spatial correlation analysis, except for the year 2000, the GUECL in the Yellow River Basin presents a general distribution characteristic of spatial agglomeration, which is positively correlated in 2006, 2012 and 2018. The change of spatio-temporal pattern is the result of internal and external factors. The former mainly displays in the main characteristics of farmers, family characteristics and farmers’ cognition, while the latter is reflected in natural, social and policy factors.