Evaluation and simulation of the impact of land use change on ecosystem services based on a carbon flow model: A case study of the Manas River Basin of Xinjiang, China

Impact of agricultural irrigation and resettlement practices on carbon storage in arid inland river basins: A case study of the Shule river basin

Agricultural irrigation and resettlement have significant impacts on carbon storage in arid inland river basins. With the background of "Comprehensive development measures for agricultural irrigation and resettlement in Shule River Basin (SRB)", this paper uses land use data to estimate regional carbon storage through InVEST model and revises the result by using net ecosystem productivity (NEP). The influence of land use change on carbon storage and the driving factors of carbon storage spatial differentiation were analyzed by using the optimal parameters geographical detector (OPGD). It can be inferred from the results that: (1) During 2000-2020, the increase of cropland and grassland area is the main type of land use change in the central oasis area of Yumen City and Guazhou County. Cumulative carbon storage increased by 1.75 × 107 t. (2) NEP in the central oasis area of Yumen City and Guazhou County showed a fluctuating upward trend, and it generally behaves as a carbon sink. The average annual NEP was 1.78 × 105 t, and the carbon sink increased by 0.95 × 105 t. (3) The main factors responsible for driving are vegetation, elevation, potential evapotranspiration, and precipitation. The explanatory power of each factor in carbon storage spatial differentiation was enhanced by the interaction between natural and anthropogenic factors. The interaction between vegetation and the human factor is more significant than that of the human single factor. (4) Agricultural irrigation and resettlement measures did not cause a decline in ecosystem carbon storage in Yumen City and Guazhou County in the central part of SRB. Conversely, the region's ecosystems have seen an increase in carbon storage as a result of the increase in cropland. (5) The introduction of the NEP modification method and the OPGD model improves the accuracy of carbon storage estimation and obtains better driving results in spatial differentiation. The study idea provides a new perspective for the estimation of carbon storage as a whole, and provides a reference basis for the formulation of ecological protection policies.

Spatial constraints or spatial dynamics? The spatial spillover effect of networks of flood regulation service flows on land-use degree

In the face of frequent floods under climate and environmental changes, it is particularly important to measure the supply and demand of flood regulation services. Using the Hainan Island as an illustrative case, this study constructs a spatial spillover model to examine the spatial correlation mode and evolution of regional land-use degree through the network of ecosystem service flow. The research results show that forests, grasslands, and reservoirs function as the primary suppliers of flood regulation services, with forests contributing significantly to the regulation of floods. High flood risk was identified in the eastern, northern, and western regions of the Hainan Island, corresponding to increased demand for flood regulation services in croplands, towns, and rural settlements within these areas. The flow of flood regulation services within the Hainan Island was found to be directed from the center to the surrounding areas, with medium and high service flows predominantly concentrated in the northern and surrounding regions. The degree of land use on the Hainan Island demonstrated an influence on socio-economic development. Additionally, the flow network of ecological services was identified as a crucial factor in spatial spillovers, reflecting the level of interaction between county units.

Differentiated factors drive the spatial heterogeneity of ecosystem services in Xinjiang Autonomous Region, China

Exploring the driving factors of changing ecosystem services is critical for supply capacity maintaining and ecological management zoning. Xinjiang of Northwest China, is considered one of the most fragile ecological environment areas. However, studies on how ecosystem services’ driving forces respond to the environmental conditions of Xinjiang are still insufficient, especially in sub–regions with considerable spatial heterogeneity. Based on 106 counties across Xinjiang, we employed models of the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) and Revised Wind Erosion Equation (RWEQ) to quantify four essential ecosystem services (carbon storage, habitat quality, and sand fixation and water yield). Then, we investigated the spatial distribution of four ecosystem services and drivers at the county scale in 2020 by using multi–scale geographically weighted regression (MGWR). The results showed that the spatial distribution of ecosystem services is higher in the north and lower in the south, and hotspots and high–value ecosystem services areas were consistent. Precipitation, temperature, and fractional vegetation cover were the dominant factors influencing the four ecosystem services. Therefore, regulating climate and increasing vegetation will maximize the improvement of regional ecosystem services in Xinjiang. Significant differences exist in the counties of the type, intensity, and direction of ecosystem services drivers. The correlation between carbon storage, habitat quality and fractional vegetation cover was more robust stronger in the south. Water yield was more closely related to fractional vegetation cover in southern Xinjiang. Under different ecological and social conditions, the impact of driving forces on ecosystem services showed different changing trends. Three suggestions for improving ecosystem services management were proposed based on our results. The comparative analysis of the driving factors of county ecosystem services in this study will help to formulate differentiated ecological protection policies and promote a sustainable supply of ecosystem services in Xinjiang. In the future, it is necessary to strengthen the long-term monitoring and evaluation of ecosystem services and the research on the interaction of multiple drivers.

Spatio-Temporal Development of Vegetation Carbon Sinks and Sources in the Arid Region of Northwest China

Drylands, which account for 41% of Earth's land surface and are home to more than two billion people, play an important role in the global carbon balance. This study analyzes the spatio-temporal patterns of vegetation carbon sinks and sources in the arid region of northwest China (NWC), using the net ecosystem production (NEP) through the Carnegie-Ames-Stanford approach (CASA). It quantitatively evaluates regional ecological security over a 20-year period (2000-2020) via a remote sensing ecological index (RSEI) and other ecological indexes, such as the Normalized Difference Vegetation Index (NDVI), fraction of vegetation cover (FVC), net primary productivity (NPP), and land use. The results show that the annual average carbon capacity of vegetation in NWC changed from carbon sources to carbon sinks, and the vegetation NEP increased at a rate of 1.98 gC m-2 yr-1 from 2000 to 2020. Spatially, the annual NEP in northern Xinjiang (NXJ), southern Xinjiang (SXJ) and Hexi Corridor (HX) increased at even faster rates of 2.11, 2.22, and 1.98 gC m-2 yr-1, respectively. Obvious geographically heterogeneous distributions and changes occurred in vegetation carbon sinks and carbon sources. Some 65.78% of the vegetation areas in NWC were carbon sources during 2000-2020, which were concentrated in the plains, and SXJ, the majority carbon sink areas are located in the mountains. The vegetation NEP in the plains exhibited a positive trend (1.21 gC m-2 yr-1) during 2000-2020, but this speed has slowed since 2010. The vegetation NEP in the mountain exhibited only intermittent changes (2.55 gC m-2 yr-1) during 2000-2020; it exhibited a negative trend during 2000-2010, but this trend has reversed strongly since 2010. The entire ecological security of NWC was enhanced during the study period. Specifically, the RSEI increased from 0.34 to 0.49, the NDVI increased by 0.03 (17.65%), the FVC expanded by 19.56%, and the NPP increased by 27.44%. Recent positive trends in NDVI, FVC and NPP have enhanced the capacity of vegetation carbon sinks, and improved the eco-environment of NWC. The scientific outcomes of this study are of great importance for maintaining ecological stability and sustainable economic development along China's Silk Road Economic Belt.

Constructing a resilient ecological network by considering source stability in the largest Chinese urban agglomeration

The dynamics of ecological sources and their impact on the resilience of ecological networks (ENs) have attracted increasing attention from both researchers and managers. Although a couple of studies have recognized the source-loss effects on network resilience, there is a knowledge gap in integrating spatiotemporal changes of the sources while constructing resilient ENs. Here, we propose the concept of dynamic stability (DS) to explore the sources' changes over a certain period and improve source identification by grading the DS in the largest urban agglomeration located in the middle reaches of the Yangtze River in China. An investigation of the five selected ecosystem service (ES) indicators in 2000, 2010, and 2018 identified 49, 54, and 68 preliminary sources, respectively, from which 11, 14, and three sources were extracted, respectively, with high, moderate, and low levels of DS, respectively. A three-tier EN was constructed by considering both the ESs and DSs of the extracted sources. The constructed network was scale-free and featured in small world in topology analysis. Moreover, a carefully designed attack test found that this EN was of good resilience as the three critical nodes that might cause a marked decay of resilience were in high or moderate DSs and were preferentially protected by the Ecological Conservation Red Line policy in China. In conclusion, the improved approach of considering the DSs of sources may help to precisely identify and protect the critical nodes threatening network resilience, which is highly desired in constructing ENs facing various rapid changes, especially in large-scale urbanized areas.

Landscape Ecological Risk Assessment Based on Land Use Change in the Yellow River Basin of Shaanxi, China

The Yellow River Basin in Shaanxi (YRBS) has a relatively fragile ecological environment, with severe soil erosion and a high incidence of natural and geological disasters. In this study, a river basin landscape ecological risk assessment model was constructed using landscape ecology principles to investigate the temporal and spatial evolution, as well as the spatial autocorrelation characteristics of landscape ecological risks in the YRBS over a 20-year period. The main findings from the YRBS were that the land use types changed significantly over the span of 20 years, there was spatial heterogeneity of the landscape pattern, and the ecological risk value was positively correlated. The threat of landscape ecological risks in YRBS is easing, but the pressure on the ecological environment is considerable. This study provides theoretical support administrative policies for future ecological risk assessment and protection, restoration measures, and control in the Yellow River Basin of Shaanxi Province.

Land Change Science and the STEPLand Framework: An Assessment of Its Progress

This contribution assesses a new term that is proposed to be established within Land Change Science: Spatio-TEmporal Patterns of Land (‘STEPLand’). It refers to a specific workflow for analyzing land-use/land cover (LUC) patterns, identifying and modeling driving forces of LUC changes, assessing socio-environmental consequences, and contributing to defining future scenarios of land transformations. In this article, we define this framework based on a comprehensive meta-analysis of 250 selected articles published in international scientific journals from 2000 to 2019. The empirical results demonstrate that STEPLand is a consolidated protocol applied globally, and the large diversity of journals, disciplines, and countries involved shows that it is becoming ubiquitous. In this paper, the main characteristics of STEPLand are provided and discussed, demonstrating that the operational procedure can facilitate the interaction among researchers from different fields, and communication between researchers and policy makers.

Estimation and Potential Analysis of Land Population Carrying Capacity in Shanghai Metropolis

It is of great practical significance to understand the current situation of urban land carrying capacity, explore its potential space, and continuously improve the economic adaptability and resilience and population carrying capacity of megacities. Based on the guiding principle of territorial spatial division and the concept of moderate-scale resilient cities, combined with GIS technology, this study aims to divide land spaces into three types and construct different index systems to evaluate the land carrying capacity of Shanghai in different spaces. Furthermore, we propose different schemes of estimating subspace land population carrying capacity, and the carrying potential of land population is analysed as well. The acquired results demonstrate three key points. Firstly, the total land population capacity of Shanghai is estimated at 25,476.61–32,047.27 people, with urban land space being the most dominant for the city’s population carrying capacity. Furthermore, the inner suburbs carry the largest population, and the urban centre carries a larger population density than other areas. Secondly, there are significant spatial differences in land population carrying potential. Compared with the demographic data from 2017, Shanghai still has a population carrying potential of 1293.30–7863.97 people and a suitable population carrying potential of 4578.64 people. The population of the urban centre is near the upper limit of the estimated population carrying capacity, and the suburbs, especially the outer suburbs, have large population carrying potential. Thirdly, the estimation method adopted in this study can effectively reveal the spatial differences in population carrying capacity and the potential of different land spaces and different regions in Shanghai, with the estimation results being highly credible. The results will provide references for the improvement of the multi-scenario population planning strategy in Shanghai, as well as enrich the research span and methods currently employed in land carrying capacity.

Multi-Scenario Simulation and Trade-Off Analysis of Ecological Service Value in the Manas River Basin Based on Land Use Optimization in China

Rapid socio-economic development has had a significant impact on land use/cover (LULC) changes, which bring great pressure to the ecological environment. LULC changes affect ecosystem services by altering the structure and function of ecosystems. It is of great significance to reveal the internal relationship between LULC changes and ecosystem service value (ESV) for the protection and restoration of ecological environments. In this study, based on the spatial and temporal evolution of ecological service values in the Manas River basin from 1980 to 2020 and considering ecological and economic benefits, we coupled the gray multi-objective optimization model (GMOP) and patch-generating land-use simulation (PLUS) model (GMOP–PLUS model) to optimize the LULC structure under three scenarios (a natural development scenario, ND; ecological priority development scenario, (EPD); and balanced ecological and economic development scenario, EED) in 2030, and analyzed the trade-offs and synergies in the relationships among the four services. We found that from 1980 to 2020, farmland and construction land expanded 2017.90 km² and 254.27 km², respectively, whereas the areas of grassland and unused land decreased by 1617.38 km² and 755.86 km², respectively. By 2030, the trend of LULC changes will be stable under the ND scenario, the area of ecological land will increase by 327.42 km² under the EPD scenario, and the area of construction land will increase most under the EED scenario, reaching 65.01 km². From 1980 to 2020, the ESV exhibited an upward trend in the basin. In 2030, the ESV will increase by 7.18%, 6.54%, and 6.04% under the EPD, EED, and ND scenarios, respectively. The clustering of the four services is obvious in the desert area and around the water system with “low–low synergy” and “high–high synergy”; the plain area and mountainous area are mainly “high–low trade-off” and “low–high trade-off” relationships. This paper provides a scientific reference for coordinating economic development and ecological protection in the basin. It also provides a new technical approach to address the planning of land resources in the basin.

The Trade-Offs/Synergies and Their Spatial-Temporal Characteristics between Ecosystem Services and Human Well-Being Linked to Land-Use Change in the Capital Region of China

With the rise of the strategy of Coordinated Development for the Beijing-Tianjin-Hebei Region, it is necessary to evaluate the trade-offs/synergies of the survival environment and human well-being in Hebei, the capital region of China. However, existing methods cannot analyze and express trade-offs/synergies of two or more variables simultaneously. Therefore, this paper proposes a new framework to express the trade-offs/synergies among land-use intensity, ecosystem services, and human well-being. In this paper, we first identified the land-use intensity change and land-use transformation and evaluated ecosystem services and human well-being in Hebei from 2000–2015 under the Millennium Ecosystem Assessment framework. Then, the trade-offs/synergies of the three indicators were determined by GIS-based methods and MATLAB. The results show that land-use intensity and human well-being mainly present a synergistic relationship, while ecosystem services and land-use intensity mainly present a trade-off relationship, and ecosystem services and human well-being also present a trade-off relationship in Hebei during 2000–2015. In addition, some regional solutions to achieve sustainable development were proposed: region 1 needs to adjust land-use structure, region 2 needs to protect the ecological environment to improve the supply of ecosystem services, and region 3 needs to commit to improving the regional comprehensive human well-being. This study not only proposes a new framework for analyzing trade-offs/synergies of land use intensity, ecosystem services, and human well-being, but it also provides regional solutions for Hebei to achieve sustainable development.

Modelling the Impact of Land Cover Changes on Carbon Storage and Sequestration in the Central Zagros Region, Iran Using Ecosystem Services Approach

Central Zagros region in Iran is a major hotspot of carbon storage and sequestration which has experienced severe land cover change in recent decades that has led to carbon emission. In this research, using temporal Landsat images, land cover maps were produced and used in Land Change Modeler to predict land cover changes in 2020, 2030, 2040 and 2050 using Multilayer Perceptron Neural Network and Markov Chain techniques. Next, resultant maps were used as inputs to Ecosystem Services Modeler. The Intergovernmental Panel on Climate Change (IPCC) report data was used to extract carbon data. Results show that between 1989–2013 about half of forests have been destroyed. Prediction results show that by 2050 about 75% of existing forests will be lost and between 2013–2020 about 157,000 Mg carbon and by 2050 about 565,000 Mg carbon will be lost with more than US$1.9 million to 2020 and AU$3.2 million by 2050 economic compensation.

Recent Oasis Dynamics and Ecological Security in the Tarim River Basin, Central Asia

As an important agricultural and gathering area in arid inland areas of China, the ecological environments of oasis areas are more sensitive to regional climate change and human activities. This paper investigates the dynamic evolution of the oases in the Tarim River basin (TRB) and quantitatively evaluates the regional ecological security of oases via a remote sensing ecological index (RSEI) and net primary productivity (NPP) through the Carnegie–Ames–Stanford approach (CASA) from 2000 to 2020. The results indicate that the total plain oasis area in the TRB during the study period experienced an increasing trend, with the area expanding by 8.21%. Specifically, the artificial oases (cultivated and industrial land) showed a notable increase, whereas the natural oases (forests and grassland) exhibited an apparent decrease. Among the indictors of oasis change, the Normalised Difference Vegetation Index (NDVI) increased from 0.13 to 0.16, the fraction of vegetation cover (FVC) expanded by 36.79%, and NPP increased by 31.55%. RSEI changes indicated that the eco-environment of the TRB region went from poor grade to general grade; 69% of the region’s eco-environment improved, especially in western mountainous areas, and less than 5% of the regions’ eco-ecological areas were degraded, mainly occurring in the desert-oasis ecotone. Changes in land- use types of oases indicated that human activities had a more significant influence on oases expansion than natural factors. Our results have substantial implications for environment protection and sustainable economic development along the Silk Road Economic Belt.

Exploring Spatiotemporal Variation of Carbon Storage Driven by Land Use Policy in the Yangtze River Delta Region

Land use/land cover (LULC) change driven by land use policy always leads to dramatic change in carbon storage and sequestration, especially in a rapidly urbanizing region. However, few studies explored the influences of land use polices on carbon storage and sequestration in a rapidly urbanizing region. Through Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model, the spatial-temporal pattern of carbon storage altered by LULC transformation and its linkage with land use policies were analyzed in five periods (1990–1995, 1995–2000, 2000–2005, 2000–2010, 2010–2015) in the Yangtze River Delta (YRD) Region. The results indicated that: (1) the carbon storage in the YRD was substantially altered by continuous LULC transformation, totally decreased by 1.49 × 107 Mg during 1990–2015. (2) The total amount of carbon storage increased from 2.91 × 109 Mg in 1990 to 2.95 × 109 Mg in 1995, and then decreased to 2.90 × 109 Mg in 1995–2015. Thus, the total economic value of carbon storage increased approximately from 467.42 million dollars in 1990 to 472.99 million dollars in 1995, and then decreased to 465.01 million dollars in 2015. (3) The carbon storage and sequestration were influenced by LULC transformation driven by land use policies in five periods: large areas of grassland converted to woodland in 1990–1995 led by Forest Law, then clustered areas of cropland converted to built-up land in 1995–2015 around large cities of YRD Region led by Land Management Law and Development Plans, and finally, the conversion of cropland to built-up land was decreased and scattered in the entire region influenced by land use polices led by early stage of ecocivilization construction. The study can facilitate to develop regional land use policy for carbon storage conservation and carbon neutrality in a rapidly urbanizing region.

Effect of income and energy efficiency on natural capital demand

This study explores the driving forces of natural capital demand to help solve the new problems faced by China's regional sustainable development and formulate relevant policies on resource utilization, ecological compensation, and energy structural adjustment. We find a significant and inverted U-shaped relationship between income and natural capital demand. Both economic development and environmental protection can only be improved beyond the inflection point. Energy efficiency is also closely related to natural capital demand, and its continuous improvement can slow down the rise in natural capital demand. This research provides important implications for the spread and allocation of natural capital regionally. It recommends the national allocation of natural capital, formulation of differentiated environmental policies, and improvement in energy efficiency by improving scale, technology, and structure.

The Process-Mode-Driving Force of Cropland Expansion in Arid Regions of China Based on the Land Use Remote Sensing Monitoring Data

The center of gravity of China’s new cropland has shifted from Northeast China to the Xinjiang oasis areas where the ecological environment is relatively fragile. However, we currently face a lack of a comprehensive review of the cropland expansion in oasis areas of Xinjiang, which is importantly associated with the sustainable use of cropland, social stability and oasis ecological security. In this study, the land use remote sensing monitoring data in 1990, 2000, 2010 and 2018 were used to comprehensively analyze the process characteristics, different modes and driving mechanisms of the cropland expansion in Xinjiang, as well as its spatial heterogeneity at the oasis area level. The results revealed that cropland in Xinjiang continued to expand from 5803 thousand hectares in 1990 to 8939 thousand hectares in 2018 and experienced three stages of expansion: steady expansion, rapid expansion, and slow expansion. The center of gravity of cropland showed the characteristic of shifting to the South. Edge expansion and encroachment on grassland were the dominant spatial pattern mode and land use conversion mode of Xinjiang’s cropland expansion, respectively. The expansion of cropland in Xinjiang was affected by multiple factors. Irrigation conditions played a dominant role. Topography indirectly affected cropland expansion by affecting the suitability of agricultural production and development. Population growth and farmers’ income were important driving forces. There was significant spatial heterogeneity in the intensity, mode and driving force of cropland expansion among different oasis areas in Xinjiang. The spatial shift of China’s new cropland has occupied a large amount of water resources and ecological land in Xinjiang and exacerbated the vulnerability of the ecosystem in arid regions. The key to sustainable management of cropland in Xinjiang in the future lies in maintaining an appropriate scale of cropland and promoting the coordinated development of cropland, population, water resources and industry.

Assessing spatio-temporal patterns and driving force of ecosystem service value in the main urban area of Guangzhou

Increasing human activity around the world has greatly changed the natural ecosystem and the services it provides. In the past few decades, a series of significant changes have taken place in land use/land cover (LULC) in China due to the rapid growth in population, particularly in the cities of the Zhujiang Deita. However, there have been few attempts to study the co-evolution of land use/land cover change and ecosystem service value (ESV) in the main urban area of Guangzhou. Therefore, based on Landsat TM/OLI images from 1987, 1993, 1999, 2005, 2011 and 2017, the weight vector AdaBoost (WV AdaBoost) multi-classification algorithm was utilized to extract LULC data sets, and the spatiotemporal patterns of LULC over these periods were studied. The ESV was estimated and the driving force was analysed. The effect of LULC dynamics on the ESV was evaluated. The results showed that great changes have taken place in LULC in the main urban area of Guangzhou from 1987 to 2017, of which the most significant was the large-scale expansion of the built-up area that occurred through degradation of the forest and cultivated land. The proportion of forest and cultivated land decreased from 43.12% and 34.23% to 25.88% and 12.59%, respectively. The results between periods revealed a decrease in total ESVs from 5.63 × 109 yuan in 1987 to 5.27, 4.16, 4.62, 3.76 and 4.47 × 109 yuan in 1993, 1999, 2005, 2011 and 2017, respectively. In total, ESVs decreased by 1.16 billion yuan (20.61%) from 1987 to 2017. Water supply, food production, nutrient cycling and gas regulation were the four principal ecosystem service functions that affected the total ESVs. Forest, water body and cultivated land areas played a key role in ecosystem services. Therefore, we advocate that when protecting natural ecosystems in the future land use management in Guangzhou should be prioritized.

Analysis of driving forces on wetland ecosystem services value change: A case in Northeast China

Social development and changes in natural conditions have seriously affected the ecosystem services value (ESV) of wetlands. It is important for social sustainable development and human welfare to identify and evaluate the driving factors that lead to changes in ESVs. Based on the land use data of Northeast China (NEC) from 1980 to 2015, the Emergy method and Logarithmic Mean Divisia Index decomposition analysis (LMDI) was applied to calculate the main ESVs of wetlands and clarify the contributions of different driving factors to ESVs changes. The results showed that the value of provision services (ESV_p) and cultural services (ESV_c) increased significantly, while the value of regulation services (ESV_r) and supporting services (ESV_s) decreased. Overall, the ESV of wetlands increased by 7.31 × 10²² solar emjoules (sej), with a growth rate of 127.73%. The most obvious factors driving ESV changes were the wetland supporting factor (△GA), per capita GDP factor (△PG), and protection investment factor (△T). The combined average contribution weight of the three factors was above 50%. From the perspective of driving force category, social-economic development effect had the greatest impact on ESVs, with average contribution weights ranging from 45.18% to 54.59%, followed by human activity effect, average contribution weights ranging from 33.45% to 40.14%, and the influence of natural factor effect was relatively small. The research results would provide a reference for protecting and improving the ESV of the wetland ecosystem.

Evaluation and Tradeoff Analysis of Ecosystem Service for Typical Land-Use Patterns in the Karst Region of Southwest China

Although many land-use patterns have been established to restore vegetation and eliminate poverty in the karst area in southwest China, the ecosystem services (ESs) of these patterns are still not fully understood. To compare the differences in seven typical monoculture patterns and three agroforestry patterns, their ESs and tradeoffs were analyzed within the Millennium Ecosystem Assessment Framework. Compared with the local traditional corn pattern, the marigold pattern improved provisioning, regulating, and cultural services by >100%. The pomegranate pattern provided far more provisioning services than the other patterns. The apple + soybean intercropping pattern reduced regulating services, and eventually, its Total ESs (TES) and ecosystem multifunctionality index (EMF) also decreased. Cultural services will be enhanced by the introduction of fruit trees, as well as intercropping. Orange + peach had the greatest negative tradeoffs between provisioning and regulating services (P-R), provisioning and supporting services (P-S), and provisioning and cultural services (P-C), which indicates that the provisioning services urgently require improvement. Peach + pumpkin intercropping decreased the negative tradeoffs of P-R, P-S, and P-C (all > 10%), while pomegranate + grass intercropping increased the negative tradeoffs of R-S and R-C (all > 100%). Our results suggest that all six of these patterns are worthy of promotion but the pomegranate pattern should be given priority. Among the three intercropping patterns studied herein, the apple + soybean pattern should be redesigned to improve performance.

Evaluating the ecological benefits of plantations in arid areas from the perspective of ecosystem service supply and demand-based on emergy analysis

Plantations can significantly improve the ecological environment of arid areas. However, in the arid area of Northwestern China, plantations consume several thousand cubic meters of water per hectare per year, which also has a negative effect. By evaluating the relationship between the supply and demand of ecosystem services, the positive and negative benefits of plantations can be effectively identified for regional sustainable development. This study took typical arid regions as examples and evaluated the changes in ecosystem services before and after the conversion of a desert shrub system to a plantation system based on emergy analysis. The relationship between the supply and demand of various ecosystem services from different stakeholder perspectives was investigated and combined with the degree of ecosystem service demand obtained from the participatory survey. Results showed the following. (1) The ecosystem services provided by vegetation increased, the ecosystem services provided by water resources decreased, and the total service decreased by 6.89E+17 sej. (2) The relationship between the supply and demand of ecosystem services provided by water resources was of the "low-high" type. Dust purification was of the "high-high" type, and carbon sequestration and soil conservation were of the "high-low" type. (3) From the perspective of citizens, the matching degrees of the supply and demand of dust purification and soil conservation services were 21.75% and 9.38% higher than those of farmers, respectively. From the perspective of farmers, the matching degrees of the supply and demand of water supply, water purification, power supply and sediment transport, and carbon sequestration were 9.90%, 10.96%, 3.22%, and 18.28% higher than those of citizens, respectively. In summary, attention should be given to the efficient use and conservation of water resources and the promotion of the coordinated development of ecosystem services by comparing the differences in matching degrees of supply and demand among different stakeholders when constructing plantations. Meanwhile, the distribution of water resources should be given attention to protect the water demand of citizens in a targeted manner for effectively improving the level of regional well-being.

Quantitative Assessment for the Dynamics of the Main Ecosystem Services and their Interactions in the Northwestern Arid Area, China

Evaluating changes in the spatial–temporal patterns of ecosystem services (ESs) and their interrelationships provide an opportunity to understand the links among them, as well as to inform ecosystem-service-based decision making and governance. To research the development trajectory of ecosystem services over time and space in the northwestern arid area of China, three main ecosystem services (carbon sequestration, soil retention, and sand fixation) and their relationships were analyzed using Pearson’s coefficient and a time-lagged cross-correlation analysis based on the mountain–oasis–desert zonal scale. The results of this study were as follows: (1) The carbon sequestration of most subregions improved, and that of the oasis continuously increased from 1990 to 2015. Sand fixation decreased in the whole region except for in the Alxa Plateau–Hexi Corridor area, which experienced an “increase–decrease” trend before 2000 and after 2000; (2) the synergies and trade-off relationships of the ES pairs varied with time and space, but carbon sequestration and soil retention in the most arid area had a synergistic relationship, and most oases retained their synergies between carbon sequestration and sand fixation over time. Most regional relationships of sand fixation and soil retention with a weak trade-off during the before-2000 stage turned into weak synergies at the after-2000 stage; (3) the ES pairs of carbon sequestration and sand fixation had significant time-lagged trade-off relationships in most arid areas, and these time trade-offs were generally maintained for 2–6 years, where a higher absolute value of the maximum time-lagged correlation coefficient corresponded to a longer time-lag. This study could assist us in understanding the trade-off and synergy of ESs and will provide quantitative zonal information for the ecosystem-services-based ecomanagement of arid areas.

Assessment of changes in oasis scale and water management in the arid Manas River Basin, north western China

Modern water-saving irrigation technology has expanded the scale of agricultural oases in arid and semi-arid regions of China. In this study, we used Landsat MSS and Landsat TM/ETM remote sensing data to assess changes in oasis scale and water availability with reference to differing water management practices in the Manas River Basin of north-western China from 1975 to 2015. We used the water-heat balance index H₀ to determine oasis stability over time and constructed a suitable-scale calculation model for arid and semi-arid regions to assess the suitable development scale and cultivated land area in the study area. The implementation of water-saving technology in 2000 effectively improved the utilization efficiency of water resources and accelerated the formation of artificial oases; these expanded by 3873.3 km² while natural oasis area was reduced by 3485.0 km². The oasis stability index H₀ was less than the critical stability index of 0.5 throughout the study period, implying that these areas were in a metastable state and unsuitable for further development. Therefore, in order to improve oasis stability, both scale and agricultural area should be further controlled. At present, actual oasis scale exceeds appropriate scale by 1.1 times and agricultural area exceeds suitable area by 2.5 times. To ensure the stability of the oasis, its area should be maintained at 3942.28-4481.06 km² and the cultivated land should be maintained at 1576.91-1792.42 km².

Spatio-temporal evolution scenarios and the coupling analysis of ecosystem services with land use change in China

Ecosystem service (ES) supply and demand are affected by changes in land use and the supply of specific ecosystem services for human consumption, respectively. Future spatio-temporal dynamics and their coupling relations with land use in China have not been well analysed. In this study, based on future land use scenarios of Li's database, ES supply, demand and balance (supply minus demand) were revealed utilizing land use and land cover (LULC) matrix model in China in 2010, 2050 and 2100. The results showed that ES supply, demand and balance had great spatial and temporal variations under different scenarios at national and provincial scales. Higher population and higher urban expansion scenarios will lead to a significant decreasing in the balance values of different categories and total ESs in most provinces. The ecological sensitivity index was calculated to indicate the impact of land use intensity on ecosystem services. The results showed that the sensitivity levels in approximately 90% of provinces were low for all the scenarios, as only Anhui, Zhejiang, Jiangxi and Liaoning in 2050 and Gansu in 2100 were extremely sensitive to changes in supply, while only provinces in the central-eastern regions were sensitive with obvious differences from the demand. The coupling coordination analysis between land use intensity and ES balance was applied to identify the provinces with low-level coordination in land use and ES management. The results showed that the coordination change in most provinces remained stable under four scenarios. However, some provinces displayed an improving trend from low to moderate coordination or from moderate to high coordination and a degrading trend from moderate to low coordination or from high to moderate coordination from 2010 to 2100. This study contributes to exploring the effect of land use on ecosystem service evolution, thereby providing credible guidance for future land and ES management.

Human modified landscape structure and its implication on ecosystem services at Guder watershed in Ethiopia

We investigated the impacts of landscape structure changes on ecosystem services for Guder watershed. We first analyzed remotely sensed data of four decades (1973-2015). The raster data sets of land uses were used as an input in FRAGSTAT to analyze the magnitude of fragmentation. Furthermore, the locally modified ecosystem service values to estimate the ESVs for the watershed were used. Results indicated that grasslands, shrub land, and forest lands reduced by 83.5%, 48.5%, and 37.5%, whereas the corresponding increase was recorded for settlement and cultivated land by 572.2% and 7.1%. Fragmentation analysis showed an increase in class area (CA) for cultivated land and settlement, whereas number of patches (NP) rose for forest land, shrub land, grassland, settlement, and cultivated land signifying the extent of fragmentation. The overall ESVs of the watershed decreased due to the changes in landscape structure. We recommend the need to take in to account landscape-level watershed conservation to enhance ecosystem services.