Ecosystem services response to urbanization in metropolitan areas: Thresholds identification

Urbanisation and ecosystem health in the Middle Reaches of the Yangtze River urban agglomerations, China: A U-curve relationship

Rapid urbanisation in global urban agglomerations has caused serious disturbances to the structure, function, and health state of ecosystems. Investigating the driving mechanisms behind the impact of urbanisation level (UL) on ecosystem health index (EHI) is important for constructing ecological civilisation and developing superior urban agglomerations in China. However, no in-depth studies exist on these mechanisms in various urban agglomerations, which makes formulation and implementation of effective ecosystem management and control policies difficult. In this study, we estimated UL and EHI based on multisource data, and a set of spatial regression models were then used to analyse the driving mechanisms at global and local scales in the Middle Reaches of the Yangtze River urban agglomeration (MRYRUA) in China between 1995 and 2015. Our results demonstrated that EHIs in the MRYRUA were 0.627, 0.613, and 0.610 in 1995, 2005, and 2015, respectively, with 2.71% decreases during the study period. The EHI in the surrounding mountainous regions was considerably higher than that in the plains. There was a significant spatial dependence between the UL and EHI. Low UL and high EHI, high UL and low EHI, and low UL and low EHI were the dominant relationship types in the MRYRUA (25.61%, 11.83%, and 11.27%, respectively). A 10% increase in UL resulted in 1.79%, 2.50%, and 2.99% decrease in EHI for each reference year in the spatial error model with lag dependence model. A U-shaped relationship was identified between UL and EHI in different urban agglomerations and cities of different administrative levels. Therefore, the results of this study can provide a scientific basis for the formulation of macro-control policies and locally specific control policies for ecosystem protection in the MRYRUA.

Elevation dependency of ecosystem services supply efficiency in great lake watershed

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

Distinguishing the impacts of land use change in intensity and type on ecosystem services trade-offs

Changes in land use intensity and types can affect the structure and function of ecosystems, and thus ecosystem services (ESs) as well as their interactions. However, the impacts of changes in land use intensity on ESs remain poorly understood. Through four different land use scenarios, we distinguished the independent contribution of changes in agricultural land use intensity and types to grain production (GP), water purification (WP), and their trade-offs in the Dongting Lake Basin. The results showed that from 1990 to 2015, GP increased across 58.07% of the total area, but WP decreased across 64.81% of the study area. The two ESs simultaneously increased or decreased across 41.93% of the total area. Watersheds covering 48.72% of the study area where GP increased and WP decreased were mainly distributed in areas with increased land use intensity. The other regions where GP decreased and WP increased were mainly distributed in areas with decreased land use intensity. The scenario analysis of GP, WP, and their trade-offs showed that the areas where agricultural land use intensity was the dominant factor were as large as 1.95 times, 2.38 times, and 2.43 times those dominated by land use type respectively, under the same climate conditions. This study highlighted the importance of changes in agricultural land use intensity on ES, which provided further supporting to ES-based land use management.

Spatial Characteristics of Land Use Multifunctionality and Their Trade-Off/Synergy in Urumqi, China: Implication for Land Space Zoning Management

Identifying and exploring the spatial characteristics of land use multifunctionality (LUMF) and their trade-off/synergy are the basis for promoting the coordinated development of LUMF, and have significant implications for land space zoning management. In this study, we integrated multi-source data to construct a multi-functional identification system of land use, and quantitatively identified agricultural production function (APF), urban life function (ULF), and ecological function (EF) from grid units. We used the mechanical equilibrium model and Spearman correlation variable analysis to explore the trade-off/synergy between the primary and secondary function of land use. The results show that LUMF has obvious spatial differentiation characteristics and significant composite characteristics. Functionality interweaves and overlaps spatially, creating trade-off/synergy between LUMF. Urumqi as a whole was at a coordinated level (73%). High urban life–low agricultural production and high ecology–low agricultural production were the main types of trade-off/synergy. APF and EF were dominant functions, and there was a significant synergistic relationship. APF and urban life-bearing function had a trade-off relationship. Based on the research results, zoning attempts were made as a reference. Finally, under the framework of regional function theory, we considered the sequential selection process and competition process of LUMF, and put forward proposals for land space zoning management.

Research on Expansion Characteristics of Aquaculture Ponds and Variations in Ecosystem Service Value from the Perspective of Protecting Cultivated Lands: A Case Study of Liyang City, China

In the context of global food insecurity, a large amount of cultivated land in China has been occupied by aquaculture ponds, leading to a series of variations in the ecological environment. The Chinese government pays close attention to the problem. In order to achieve sustainable development and ensure the safety of China’s cultivated land, the paper uses Liyang City as an example to discuss the spatial characteristics of the expansion of aquaculture ponds through occupying cultivated lands and analyzes the variations in ecosystem service value and cultivated land function. The conclusions are as follows: (1) 2073.24 hectares of cultivated lands were occupied for expanding aquaculture ponds in Liyang from 2009 to 2019, and there was a small number of new aquaculture ponds in the ecological protection area, which shows that the aquaculture ponds in Liyang City are at the stage of disorderly expansion; (2) the total value of ecosystem services increased by 1.43%; supply and support services values decreased, but the increase in regulation and cultural services values was sufficient to more than compensate for the mentioned losses; and (3) the expansion of aquaculture ponds leads to a decrease in the carbon storage of cultivated land, which in turn has negative impacts such as an increase in atmospheric carbon concentration.

Influence of soil properties on cadmium accumulation in vegetables: Thresholds, prediction and pathway models based on big data

Soil properties, such as soil pH, soil organic matter (SOM), cation exchange capacity (CEC), are the most important factors affecting cadmium (Cd) accumulation in vegetables. In this study, we conducted big data mining of 31,342 soil and vegetable samples to examine the influence of soil properties (soil pH, SOM, CEC, Zn and Mn content) on the accumulation of Cd in root, solanaceous, and leafy vegetables in Hunan Province, China. Specifically, the Cd accumulation capability was in the following order: leafy vegetables > root vegetables > solanaceous vegetables. The soil property thresholds for safety production in vegetables were determined by establishing nonlinear models between Cd bioaccumulation factor (BCF) and the individual soil property, and were 6.5 (pH), 30.0 g/kg (SOM), 13.0 cmol/kg (CEC), 100-140 mg/kg (Zn), and 300-400 mg/kg (Mn). When soil property values were higher than the thresholds, Cd accumulation in vegetables tended to be stable. Prediction models showed that pH and soil Zn were the leading factors influencing Cd accumulation in root vegetables, explaining 87% of the variance; pH, SOM, soil Zn and Mn explained 68% of the variance in solanaceous vegetables; pH and SOM were the main contributors in leafy vegetables, explaining 65% of the variance. Further, variance partitioning analysis (VPA) revealed that the interaction effect of the corresponding key soil properties contributed mostly to BCF. Meanwhile, partial least squares (PLS) path modeling was employed to analyze the path and the interactive effects of soil properties on Cd BCF. pH and SOM were found to be the biggest two players affecting BCF in PLS-models, and the most substantial interactive influence paths of soil properties on BCF were different among the three types of vegetables.

A Synthetic Landscape Metric to Evaluate Urban Vegetation Quality: A Case of Fuzhou City in China

Urban vegetation plays a very important role in regulating urban climate and improving the urban environment. There is an urgent need to construct an effective index to quickly detect urban vegetation quality changes. In this study, a synthetic vegetation quality index (VQI) was proposed using a holistic approach based on the quality of vegetation itself and the spatial relationship with its surroundings, composed of four selected variables: normalized difference vegetation index (NDVI), patch aggregation index (AI), patch density (PD), and percentage of landscape (PLAND). Principal component analysis (PCA) was employed to calculate weights for each variable due to its objectivity. Then, taking Fuzhou City, southeast China as the case study, the scale effects of the VQI under different moving window sizes (500 m, 1 km, 2 km, …, 5 km) and the spatiotemporal changes were explored. The results showed that a VQI with a window size of 3 km had the highest correlations with all the selected indicators. Meanwhile, the representativeness and the effectiveness of the VQI were validated by the percentage eigenvalues of PC1, as well as Pearson correlation analysis and bivariate spatial autocorrelation analysis. We also revealed that the proposed VQI had the greatest explanatory power for land surface temperature (LST) among all the factors in both studied years (2000 and 2016), with the VQI’s interpretation of LST being 0–44% better than any individual indicator except for AI in 2000. Additionally, our work revealed that the location of vegetation has a great impact on the urban thermal environment. The VQI can assess urban vegetation quality effectively and quickly.

Study on Eco-Environmental Effects of Land-Use Transitions and Their Influencing Factors in the Central and Southern Liaoning Urban Agglomeration: A Production–Living–Ecological Perspective

From the perspective of the production–living–ecological space, this paper reclassifies the land-use categories in the central and southern Liaoning urban agglomeration in the years 1990, 2000, 2010 and 2018. It then quantitatively analyzes the spatiotemporal evolution characteristics of land-use transitions by adopting the land-use transfer matrix and other methods. This paper further uses the eco-environmental quality index and ecological contribution rate to explore the eco-environmental effects of the land-use transition. Finally, it identifies the influencing factors of the eco-environmental effect and the spatial differentiation law of the effect in the study area through the multi-scale geographically weighted regression (MGWR) model. The main conclusions reached are as follows: (1) During the study period, a slow increase was seen in the ecological land of the central and southern Liaoning urban agglomeration. A sharp decline occurred in the production land, and a rapid rise was found in the living land. (2) From 1990 to 2018, the eco-environmental quality index in the study region showed significant spatial differentiation, with the distribution characteristics being high in the east and low in the west. The areas have expanded and spread along the Shenyang-Dalian axis to form medium-low quality agglomerations. The encroachment of agricultural production land and urban and rural living land on forest ecological land is the main contributor to the deterioration of the eco-environmental quality during the study period. (3) Compared with the geographically weighted regression model and the ordinary least squares model, a remarkable advancement can be seen in the MGWR model, which is more suitable for research on the influencing factors of eco-environmental quality. In addition, different influencing factors have significant spatial differences in the degree and scale of impact.

Spatially non-stationary relationships between urbanization and the characteristics and storage-regulation capacities of river systems in the Tai Lake Plain, China

Given environmental or hydrological functions influenced by changing river networks in the development of rapid urbanization, a clear understanding of the relationships between comprehensive urbanization (CUB) and river network characteristics (RNC), storage capacity (RSC), and regulation capacity (RRC) is urgently needed. In the rapidly urbanized Tai Lake Plain (TLP), China, various methods and multisource data were integrated to estimate the dynamics of RNC, RSC, and RRC as well as their interactions with urbanization. The bivariate Moran's I methods were applied to detect and visualize the spatial dependency of RNC, RSC, or RRC on urbanization. Geographically weighted regression (GWR) model was set up to characterize spatial heterogeneity of urbanization influences on RNC, RSC and RRC. Our results indicated that RNC, RSC and RRC variables each showed an overall decreasing trend across space from 1960s to 2010s, particularly in those of tributary rivers. RNC, RSC, or RRC had globally negative correlations with CUB, respectively, but looking at local scale the spatial correlations between each pair were categorized as four types: high-high, high-low, low-low, and low-high. GWR was identified to accurately predict the response of most RNC, RSC, or RRC variables to CUB (R²: 0.6-0.8). The predictive ability of GWR was spatially non-stationary. The obtained relationships presented different directions and strength in space. All variables except for the water surface ratio (Wp) were more positively affected by CUB in the middle eastern parts of TLP. Drainage density, RSC and RRC variables were more negatively influenced by CUB in the northeast compared to other parts. The quantitative results of spatial relationships between urbanization and RNC, RSC or RRC can provide location-specific guidance for river environment protection and regional flood risk management.

Monitoring ecosystem services in the Guangdong-Hong Kong-Macao Greater Bay Area based on multi-temporal deep learning

Assessment of ecosystem service supply and demand, as well as the budgets of ecosystem service supply and demand, is the basis of scientific urban planning. In the 20 years between the proposal and formation of the Guangdong-Hong Kong-Macao Greater Bay Area (GBA), the natural ecosystem has been degraded and the ecological balance has been destroyed. In this paper, in order to assess the changes in ecosystem services in the GBA, a deep learning method composed of deep change vector analysis and the ResUnet model is proposed to achieve land use/land cover (LULC) mapping for 2000 and 2020. An index-based non-monetary evaluation method is then employed to quantify the value of the ecosystem services, and the spatial and temporal characteristics of the ecosystem service changes are analyzed. The results reveal that: (1) the proposed deep learning approach that combines deep change vector analysis (CVA) and model fine-tuning is able to achieve rapid and efficient LULC mapping in a large-scale area with multi-temporal image sequences. The overall accuracy of LULC mapping is 86.06% for 2000 and 86.67% for 2020. (2) The impervious surface area of all the cities in the GBA has increased significantly between 2000 and 2020, with an overall increase of 11.95%. (3) The mismatch between supply and demand for ecosystem services in the GBA has intensified, especially for provisioning, regulation, and cultural services. (4) The spatial distribution of the ecosystem service budget changes in the GBA shows aggregation characteristics and spatially positive correlation. These findings will provide important insights for promoting the coordinated development of the regional ecosystems and social economy in the GBA.

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.

Trade-offs Between the Value of Ecosystem Services and Connectivity Among Protected Areas in the Upper Chattahoochee Watershed

The Upper Chattahoochee Watershed supplies most of the drinking water to the Atlanta Metropolitan Area, a region with one of the fastest urban growth rates in the United States. Smart conservation planning is necessary to conciliate urban development and the provision of critical ecosystem services (ESs) such as water quality, carbon storage, and wildlife habitat. We employed optimization models to compare the value of the ESs provided by alternative allocations of land parcels for conservation. We adopted boundary penalties to determine the trade-offs of choosing higher connectivity among parcels regarding economic values provided by carbon storage, wildlife habitat, and water quality. We used InVEST models to quantify and map ESs and value transfer to assign economic values to them. We set low and high ESs economic value bounds and discounted their values to perpetuity using 3% and 7% discount rates. Our results indicate that incorporating boundary penalties results in solutions with larger, fewer, and more connected parcels but yields lower economic benefits than unconstrained models. However, these differences are relatively small (between 2.6% and 7.3% loss in economic value). Additional transaction costs of purchasing more parcels and improving ecological networks provided by larger forest patches might justify the selection of solutions with higher connectivity. Decision-makers can use the developed models for estimating the economic cost of selecting connected parcels for conservation purposes at the landscape level.

Incorporating Ecosystem Service Multifunctionality and Its Response to Urbanization to Identify Coordinated Economic, Societal, and Environmental Relationships in China

Urbanization poses a threat to ecosystems and contributes to the degradation of the environment. It is of great importance to identify coordinated economic, societal, and environmental relationships with key ecological functions and services to achieve regional sustainability. Based on a case study in China, this study seeks to fill this gap by estimating the spatial distribution of ecosystem service multifunctionality (ESM) and its spatially heterogeneous response to urbanization. First, the biophysical values of five typical ecosystem services (ESs) (carbon storage, habitat quality, net primary production, soil conservation, and water yield) were assessed based on several simulation models. The biophysical values of these ESs were then standardized and summed to obtain the spatial distribution of ESM. Afterward, the urbanization level was evaluated, and finally, the spatial interaction between urbanization and ESM was exhibited based on the bivariate Moran’s I and Getis-Ord Gi* statistic. The results showed that: (1) the ESM showed obvious spatial heterogeneity in southeastern and northwestern China, with a gradual decline from the coast to the interior; (2) ESM and urbanization had different spatial distribution patterns and produced significant local aggregation effects; and (3) harmonious relationships between ESM and urbanization were observed in southeastern coastal China and the surrounding areas of the North China Plain, which were related to the capacity of local coastal ecosystems, mangrove forests, and aquatic ecosystems to provide multiple services and goods simultaneously. Our results suggest that multifunctional ecosystems can realize a ‘win–win’ situation for ecological conservation and socioeconomic development. The results of this study can advance our understanding of the ecological effects of urbanization on ecosystems and provide valuable implications for the coordinated development of humans and nature in the rapid urbanization process.

Correlative distribution of DOM and heavy metals in the soils of the Zhangxi watershed in Ningbo city, East of China

In peri-urban critical zones, soil ecosystems are highly affected by increasing urbanization, causing probably an intense interaction between dissolved organic matter (DOM) and heavy metals in soil. Such interaction is critical for understanding the biogeochemical cycles of both organic matter and heavy metals in these zones. However, limited research has reported the correlative distribution of DOM and heavy metals at high seasonal and spatial resolutions in peri-urban critical zones. In this study, 160 soil samples were collected from the farmland and forestland of Zhangxi watershed, in Ningbo, eastern China during spring, summer, fall and winter four seasons. UV-visible absorption and fluorescent spectroscopy were used to explore the optical characteristics of DOM. The results indicated a mixture of exogenous and autogenous sources of DOM in the Zhangxi watershed, while DOM in farmland exhibited a higher degree of aromaticity and humification than that in forestland. Fluorescent results showed that humic acid-like, fulvic acid-like and microbial-derived humic-like fractions were mostly affected by seasons. The distribution of heavy metals was affected mainly by land-use changes and seasons. Correlation analysis between heavy metals and DOM characteristics and components suggested that aromatic and humic substances were more favorable in binding with EDTA extractable Ni, Cu, Zn and Cd. The bioavailable Cd and Pb decreased due to binding with humic fractions, indicating its great effects on the bioavailability of Cd and Pb. Overall, these findings provide an insight into the correlative distributions of DOM and heavy metals in peri-urban areas, thereby highlighting their biogeochemical cycling in the soil environment.

Assessing the Potential Impacts of Urban Expansion on Hydrological Ecosystem Services in a Rapidly Urbanizing Lake Basin in China

Hydrological ecosystem services (HESs) such as water purification and water supply are important for providing other ecosystem services such as drinking water, recreation, and human health. Land use change caused by urbanization is a direct driver affecting the provision of HESs. The quantification and integration of HES into watershed management and urban planning have become increasingly important. In this study, we highlighted an integration of the InVEST and CLUE-S models to simulate and predict future changes of HES in a rapidly urbanizing lake basin, namely the Nansihu Lake basin of China. The spatiotemporal patterns of HESs including water yield, water purification, and sediment export in the past five decades (from 1980 to 2015) have been revealed through our integrated modeling approach. Furthermore, urbanization and land use change scenarios till 2030 were developed using land use, topography, climate, and soil data. It is found that due to the rapid expansion of urban land, water yield, total nitrogen (TN), and total phosphorus (TP) export has increased by 5.5%, 7.38%, and 7.02%, respectively, while the sediment export has decreased by 4%. As a result, the risks of flooding and water quality degradation increased. Under a hybrid ecological and farmland redline policy (EFRP) scenario, the HESs have all been significantly improved compared to the level in 2015. This research can help to predict the future changes in HESs for land use management and ecological and environmental protection in the Nansihu Lake basin.

Is China’s Urbanization Quality and Ecosystem Health Developing Harmoniously? An Empirical Analysis from Jiangsu, China

The relationship between urbanization and ecology environment is a current research hotspot. Most literature to date focuses on the interaction between urbanization and a single component of the ecosystem (e.g., water, forests, and ecosystem services), while little attention has been given to the relationship between urbanization quality and ecosystem health. Accordingly, this paper used the entropy method and vigor—organization–resilience model to measure the urbanization quality and ecosystem health in Jiangsu Province. Based on the results, this paper analyzed the spatial-temporal pattern and evolution characteristics of the coordination degree between urbanization quality and ecosystem health in Jiangsu Province in 2000, 2005, 2010, 2015, and 2017 and then used the geographic detector and Tobit regression model to explore its internal driving forces and external influencing factors. The results show the following: 1. The changing trend of urbanization quality and ecosystem health in the Jiangsu Province share some traits; it first descends and then ascends; 2. The cities in Jiangsu Province are all between primary coordination and high-quality coordination. Central Jiangsu has the best coupling coordination degree, and Northern Jiangsu has the worst coupling coordination degree, but the overall coordination degree is on the rise; 3. The internal and external factors that drive the coordinated development of urbanization and ecosystem health differ based on periodic and regional characteristics. We need to tailor policies to ensure the sustainable development of the region.

Quantifying ecosystem service mismatches for land use planning: spatial-temporal characteristics and novel approach-a case study in Jiangsu Province, China

Land use and land cover changes associated with urbanization have had a significant influence on ecosystem services (ESs), but previous studies have insufficiently focused on the relationships between ES supply and demand; these relationships are seldom considered in the science-policy frameworks of land use planning. In this study, a specific supply-demand indicator was constructed to measure ES supply and demand and their disparity across multiple scales in Jiangsu Province from 2000 to 2018. High spatial heterogeneity and mismatches of ES supply and demand were found in water yield, grain production, carbon sequestration, soil conservation, heat regulation, and recreation services. At provincial scale, the supplies of carbon sequestration and heat regulation services were smaller than their demands. At the 1-km² grid scale, the ES supply and demand mismatches in urban areas were more serious than those in surrounding areas, especially for carbon sequestration and recreation services. Five ES supply-demand risk zones were identified based on the current status and trends of all ES supply and demand. Southern Jiangsu generally had high risks of ES mismatch, which should be reduced by strategic planning. Constructing the ES supply-demand indicator is a novel practice that assists in evaluating environmental issues and integrating them into further development decisions. This paper suggests that governments should reduce ES mismatches with reference to local conditions (economic development, industrial type, and ecological carrying capacity) and the actual situation of ES supply and demand.

A Method for Identifying Urban Functional Zones Based on Landscape Types and Human Activities

The effects of land use and socioeconomic changes on urban landscape patterns and functional zones have been increasingly investigated around the world; however, our knowledge on these effects is still inadequate for sustainably managing urban ecosystems. The urban functional zone (UFZ) refers to a kind of regional space that provides specific functions for human activities and reflects the land use type in a city. They are important for urban planning and exploring urban texture dynamics. UFZs improve understanding of sustainable development for urban ecosystems with extreme environments and unique social backgrounds. However, the identification methods for UFZs are incomplete because of a lack of socioeconomic attributes, as well as their hierarchical relations. Here, we present a hierarchical weighted clustering model to identify UFZs based on the entropy weight method. The data included points of interest (POIs), land use type data, road network data, socioeconomic data, and population density. We found that the adjusted cosine metric and the average criterion were the optimal distance metric and linkage strategy, respectively, to cluster urban zone data. The performance with weighted data was better than that with raw data, and the level of the POI classification scheme and landscape pattern affected the accuracy of identification UFZs. The research indicated that the hierarchical weighted clustering model was a useful method to classify UFZs in order to improve urban planning and environmental management schemes.

Quantification of ecosystem services supply-demand and the impact of demographic change on cultural services in Shenzhen, China

Previous studies on the supply and demand of ecosystem services (ES) mainly focused on inter-annual changes, and no studies have explored the impact of demographic change on the ES supply and demand on fine-grained time scales. Thus, taking Shenzhen as an example, the status of ES supply and demand, as well as diurnal population changes and their impacts on cultural services were analyzed at different time periods using mobile phone signaling data, ecological supply-demand ratio (ESDR), Geo-Informatic Tupu, InVEST model and buffer zone. The results showed that the population declines successively on workdays, weekends and holidays, and that the daytime population is greater than the nighttime. Water yield services can basically meet the demand in terms of quantity and spatial distribution, however, carbon sequestration and cultural services showed the opposite results. The main type of ESDR changes in cultural services are the mutual conversion of deficit and balance, and these are concentrated in areas with high forest coverage and small populations, but frequent population changes. In addition, when the fixed population is too large, the use of time-varying population data will conceal the impact of demographic changes on ES supply and demand, and other data are needed for auxiliary analysis. Overall, this study provides a new research perspective for the ES supply and demand and can provide a theoretical basis for refined sustainable urban management.

Identifying ecosystem service bundles and the spatiotemporal characteristics of trade-offs and synergies in coal mining areas with a high groundwater table

Understanding the spatiotemporal characteristics of the interactions among ecosystem services (ESs) is a crucial but challenging task for maintaining human well-being and achieving sustainable regional development. However, understanding the spatiotemporal interactions of multiple ESs at different grid scales and within different ecosystem services bundles (ESBs) is relatively limited, particularly in coal mining areas with a high groundwater table (CMA-HGT) where the land use has drastically changed as a result of mining subsidence. This study examines CMA-HGT in Huainan, aiming to identify ESBs and explore the spatiotemporal characteristics of trade-offs/synergies among ESs at distinct grid scales and ESBs. Five ESs relating to provisioning, regulation, and maintenance, including food production (FP), water yield (WY), soil conservation (SC), carbon sequestration (CS), and biodiversity maintenance (BM) were quantified using different biological models during the period 1987-2018. Spatiotemporal trade-offs/synergies among ESs were explored using correlation analysis and significance tests at different scales. The spatiotemporal distributions and main characteristics of distinct ESBs were identified using a self-organizing map (SOM) and Calinski criterion. The interactions among ESs in different ESBs were detected. Relationships between ESs and land use or coal production (CP) were explored using redundancy analysis (RDA). The results demonstrate that spatiotemporal trade-offs were generally observed among provisioning services at distinct grid scales and within different ESBs. Meanwhile, spatiotemporal synergies generally appeared between regulation and maintenance services at distinct grid scales. Interactions among ESs presented temporal dynamic, spatial heterogeneity and scales dependence due to the relationships of FP-BM or SC-CS had changed with the increasing of research scales. Three ESBs-ESB1, ESB2, and ESB3-were identified at a grid of scale of 1000 m, and their spatial locations varied across different periods, but the areas of variation covered less than 24% of the study area. BM was synergistic with FP, WY, SC, and CS; while WY had only a trade-off relationship with FP in ESB1. WY had trade-off relationships with FP, SC, CS, and BM in ESB2. In ESB3, BM was synergistic with FP, SC, and CS; while it was in a trade-off relationship with WY. Cultivated land, construction land and CP were the main driving factors in the WSA, ESB1, ESB2 and ESB3. There was a certain degree of change in the relationships between ESs and land use/CP, and the relationships among ESs at different grid scales and ESBs over time and space, which indicates strong regional heterogeneity and scale dependence. These results can provide detailed guidelines for formulating spatially targeted ecosystem management, restoration programs and ES payment policies.

The Impact of Urbanization on Land: A Biophysical-Based Assessment of Ecosystem Services Loss Supported by Remote Sensed Indicators

Urbanization and related land consumption are one of the main causes of ecosystem services loss. This is especially the case for soil-related services affecting ecosystem functions and limiting accessibility to natural resources. Satellite remote sensing and environmental databases enable in-depth analysis of urban expansion and land changes, which can be used to monitor trends in the provision of ecosystem services. This work aims to describe a multilayered approach to the assessment of biophysical loss of ecosystem services flows in Italy caused by an increase in land consumption in the period 2012–2020. The results show higher losses in wood production, carbon storage, hydrological regime regulation, and pollination in the northern regions of Italy, as well as in some southern regions, such as Campania and Apulia. Habitat quality loss is widespread throughout Italy, whereas crop production loss varies on the basis of the locations in which it occurs and the crop types involved. Loss of arable land and fodder production mainly occurs in northern regions, whereas southern regions have experienced a drop in permanent crop production. This study highlights the importance of using integrated data and methodologies for well-founded approaches, with a view to gaining a thorough understanding of ecosystem services-related processes and the changes connected therewith.

Linking MSPA and Circuit Theory to Identify the Spatial Range of Ecological Networks and Its Priority Areas for Conservation and Restoration in Urban Agglomeration

Rapid urbanization has led to the continuous degradation of natural ecological space within large urban agglomerations, triggering landscape fragmentation and habitat loss, which poses a great threat to regional ecological sustainability. Ecological networks (ENs) are a comprehensive control scheme to protect regional ecological sustainability. However, in the current research about ENs, most studies can only determine the orientation of ecological corridors but not their specific spatial range. This leads to the fact that ENs can only be abstract concepts composed of points and lines, and cannot be implemented into concrete spatial planning. In this study, taking the Shandong Peninsula urban agglomeration as an example, ecological sources were identified by morphological spatial pattern analysis (MSPA) and habitat quality assessment, ecological resistance surfaces were constructed based on habitat risk assessment (HRA). And circuit theory was used to simulate the ecosystem processes in heterogeneous landscapes via by calculating the cumulative current value and cumulative current recovery value, to identify the spatial range and key areas of ecological corridors. The results showed that the ENs includes 6,263.73 km2 of ecological sources, 12,136.61 km2 of ecological corridors, 283.61 km2 of pinch points and 347.51 km2 of barriers. Specifically, ecological sources were distributed in a spatial pattern of five groups, and ecological corridors were short and dense within groups, long in distance and narrow in width between groups. The pinch points and barriers mainly exist in the ecological corridors connecting the inner and outer parts of the central city and in the inter-group corridors. In order to ensure the connectivity and effectiveness of ENs, it is necessary to focus on the pinch points and barriers and include them in the priority areas for protection and restoration. Based on MSPA and circuit theory, this study provides a new method for determining the spatial range of ENs and the specific locations of priority areas, and provides a feasible solution for the concrete implementation of ENs to achieve effective ecological protection and restoration.

Research on cropping intensity mapping of the Huai River Basin (China) based on multi-source remote sensing data fusion

As a key input variable to many global climates, land surfaces and crop models, cropping intensity (CI) accurately assesses and predicts crops' output, in view of the global decline in food production in recent years due to declining natural resources, urban expansion and declining quality of arable land. Hence, research on CI mapping can have a contribution to solve this problem. Unfortunately, existing remote sensing data for CI mapping research, including Moderate Resolution Imaging Spectroradiometer (MODIS) and Landsat images, are not adequate for obtaining CI information at higher spatial and temporal resolution. In this regard, we develop an algorithm to extract CI based on per-pixel physiognomy. To be specific, the algorithm is based on the Google Earth Engine (GEE) platform and constructs a high temporal (10 days) spatial (30 m) resolution dataset with the fusion of Landsat 7/8 and Sentinel-2 A/B image data and extracts CI information using a time series of peak discovery method, threshold method and phenological period feature extraction to obtain the 2018 Chinese Huai River Basin (HRB) CI map. Our results suggest that the overall accuracy (OA) of CI extraction in the HRB is 92.72%, with a kappa coefficient of 0.864. The single-season crop, double-season crop and three-season crop account for 41.6%, 57.7% and 0.7% of the total farmland area, respectively. Compared to existing CI identification and extraction methods, this approach achieves higher accuracy in the identification and extraction of CI information over a larger area.

Quantifying the human disturbance intensity of ecosystems and its natural and socioeconomic driving factors in urban agglomeration in South China

The impact of human activities on terrestrial ecosystems is becoming more intense than ever in history. Human disturbance analyses play important roles in appropriately managing the human-environment relationship. In this study, a human disturbance index (HDI) that uses land use and land cover data from 1980, 2000, 2010, and 2018 is proposed to assess the human disturbance of ecosystems in the Guangdong-Hong Kong-Macao Greater Bay Area. The HDI is first calculated by classifying the human disturbance intensity into seven levels and 13 categories from weak to strong in ecosystems. Then the driving factors of the HDI spatial pattern change are explored using a geographically weighted regression (GWR) model. The results showed that the spatial pattern of the HDI was high in the middle and low in the surrounding areas. The intensity of human disturbance increased, and the medium and high disturbance areas expanded during 1980-2018, especially in Guangzhou, Foshan, Shenzhen, and Dongguan. Human disturbance displayed an obvious spatial heterogeneity. The GWR model had a better explanation effect of the analysis of the HDI change drivers. The driving effect of the socioeconomic conditions was significantly stronger than that of the natural environmental. This study assists in understanding the distribution and change characteristics of the ecological environment in areas with strong human activities and provides a reference for related studies.

Quantitative Evaluation of Ecological Stress Caused by Land Use Transitions Considering the Location of Incremental Construction Lands: The Case of Southern Jiangsu in Yangtze River Delta Region

With their significance in connecting socio-economic development and related eco-environmental consequences, land use transitions have gradually become the focus of land change science and sustainability science. Although various research studies have determined the ecological effects of land use transitions and provided suggestions to regulate them, few studies have investigated the different ecological stress of construction lands from the perspective of their spatial locations in ecologically differentiated regions. Taking economically developed and highly urbanized southern Jiangsu in Eastern China as an example, we developed a process-based method to indicate the spatial heterogeneity of ecological suitability and divided southern Jiangsu into five-level ecological zones accordingly. Considering that construction lands in ecological zones with higher ecological suitability levels cause greater ecological stress, we evaluated the ecological stress levels of incremental construction lands at different stages after 1990. Then, we carried out the calculation of county-level ecological stress and county-level zoning based on both the area and ecological stress level of their incremental construction lands. Results indicated that ecological zones with the highest to lowest ecological suitability levels accounted for 49.85%, 25.73%, 15.56%, 6.51%, and 2.34%, respectively. The majority of the incremental construction lands had the highest and moderately high ecological stress levels, and they were mainly distributed in areas along the Yangtze River and around Taihu Lake. The general ecological stress level of southern Jiangsu was at a relatively high level at each stage, but the county-level patterns of ecological stress levels were spatially different. As determined from the relationship between the amount of incremental construction lands and the average stress level associated with these lands in each unit, four types of zones, i.e., H-H, H-L, L-H and L-L zones, were identified, and targeted suggestions on land use regulations were proposed. We conclude that the spatial distribution of incremental construction lands significantly affects their ecological consequences from the perspective of maintaining ecosystem integrity. Both construction lands and ecological suitability are location specific, so the location-oriented evaluations could provide an effective approach for determining the spatial patterns of land use transitions based on spatially differentiated ecological consequences. It is essential to propose location-specific policies to carry out spatially precise ecological restoration and the redistribution of incremental construction lands.

Land Use Change in the Cross-Boundary Regions of a Metropolitan Area: A Case Study of Tongzhou-Wuqing-Langfang

Since the 1980s, metropolitan areas have increased worldwide due to urbanization and regionalization. While the spatial integration of the labor and housing markets has benefitted the development of cities within metropolitan areas, they have also brought great challenges for land governance; this is particularly evident in cross-boundary regions due to the complex relations between the markets and the regulations and between governments at different levels. Extensive research has been conducted on the city-level analysis of socioeconomic integration, land use development, and urban governance within metropolitan areas; yet, it is insufficient for understanding the intricate interplay between the various forces in such regions. This study aims to reveal the dynamics of land use change from 1990–2020 and its driving forces in the recent decade in the Tongzhou-Wuqing-Langfang (TWL) region—a typical cross-boundary area between Beijing, Tianjin, and the Hebei Metropolitan Area—using Landsat imagery. We employed the land-use dynamic degree, kernel density analysis, principal component analysis, and multiple linear regression to explore the spatiotemporal patterns of land use change and its driving factors at the district/county level. The results show that the general land use changes from cultivated and forest land to urban and rural construction land across the region. The speed of the trend varies considerably over time between different areas as the land use policies and regulations of each local government change. The population growth and the tertiary and secondary industry growth are the main driving factors for the change in construction land across the whole TWL region, while the urbanization rate and fixed asset investment have different impacts across the cross-boundary region. The results suggest that expanding the integration of land use policies and regulations in the cross-boundary region is urgently required.

Assessment of Ecosystem Health and Its Key Determinants in the Middle Reaches of the Yangtze River Urban Agglomeration, China

Urban agglomerations have gradually formed in different Chinese cities, exerting great pressure on the ecological environment. Ecosystem health is an important index for the evaluation of the sustainable development of cities, but it has rarely been used for urban agglomerations. In this study, the ecosystem health in the middle reaches of the Yangtze River Urban Agglomeration was assessed using the ecosystem vigor, organization, resilience, and services framework at the county scale. A GeoDetector was used to determine the effects of seven factors on ecosystem health. The results show that: (1) The spatial distribution of ecosystem health differs significantly. The ecosystem health in the centers of Wuhan Metropolis, Changsha-Zhuzhou-Xiangtan City Group, and Poyang Lake City Group is significantly lower than in surrounding areas. (2) Temporally, well-level research units improve gradually; research units with relatively weak levels remain relatively stable. (3) The land use degree is the main factor affecting ecosystem health, with interactions between the different factors. The effects of these factors on ecosystem health are enhanced or nonlinear; (4) The effect of the proportion of construction land on ecosystem health increases over time. The layout used in urban land use planning significantly affects ecosystem health.

Biodiversity and ecosystem services mapping: Can it reconcile urban and protected area planning?

Land-use changes, especially urbanization, have largely impacted the capacity of ecosystems to deliver ecosystem services (ES) on which human wellbeing depends. The current sectorial landscape and territorial planning approaches that separately address protected areas and urban areas have proven ineffective in conserving biodiversity. To address this important challenge, integrated territorial planning has been claimed to be able to better reconcile interests between nature conservation and urban planning, and ES supply and demand mapping may be a useful tool for such purposes. In this study, we quantitatively mapped biodiversity and the supply and demand of eight ES along an urban-rural gradient in the region of Madrid (Spain). Then, we clustered the municipalities in this gradient into four groups based on their common biodiversity and ES supply and demand characteristics. Additionally, we reviewed the urban plans from these municipalities and the management plans of three protected areas, analysed the references to ES in the plans, and searched for potential conflicts between urban and protected area planning aims. We found that municipalities with highly coupled ES supply and demand are in high altitude areas, coinciding with protected areas, while in urban areas, the ES demand exceeds the supply. Municipalities exhibiting a high demand for regulating ES usually include them in their plans, while municipalities with a high supply of regulating ES do not. Given the several conflicts between protected areas and urban planning that we detected, we discuss the utility of mapping biodiversity and ES supply and demand beyond administrative boundaries to overcome the challenge of integrating spatial planning approaches, especially in the context of urban-rural gradients and megacities. We also explore the utility of these methods for coordinating urban planning tools to achieve integrated territorial planning.

Synergies between Urban Heat Island and Urban Heat Wave Effects in 9 Global Mega-Regions from 2003 to 2020

Global urbanization significantly impacts the thermal environment in urban areas, yet urban heat island (UHI) and urban heat wave (UHW) studies at the mega-region scale have been rare, and the impact study of urbanization is still lacking. In this study, the MODIS land surface temperature (LST) product was used to depict the UHI and UHW in nine mega-regions globally between 2003 and 2020. The absolute and percentile-based UHW thresholds were adopted for both daily and three-day windows to analyze heat wave frequency, and UHW magnitude as well as frequency were compared with UHI variability. Results showed that a 10% increase in urban built-up density led to a 0.20 °C to 0.95 °C increase in LST, a 0.59% to 7.17% increase in hot day frequency, as well as a 0.08% to 0.95% increase in heat wave number. Meanwhile, a 1 °C increase in UHI intensity (the LST differences between the built-up and Non-built-up areas) led to a 2.04% to 92.15% increase in hot day frequency, where daytime LST exceeds 35 °C and nighttime LST exceeds 25 °C, as well as a 3.30% to 33.67% increase in heat wave number, which is defined as at least three consecutive days when daily maximum temperature exceeds the climatological threshold. In addition, the increasing rates of UHW magnitudes were much faster than the expansion rates of built-up areas. In the mega-regions of Boston, Tokyo, São Paulo, and Mexico City in particular, the increasing rates of UHW hotspot magnitudes were over 2 times larger than those of built-up areas. This indicated that the high temperature extremes, represented by the increase in UHW frequency and magnitudes, were concurrent with an increase in UHI under the context of climate change. This study may be beneficial for future research of the underlying physical mechanisms on urban heat environment at the mega-region scale.

Analysis for the Interaction Relationship between Urbanization and Ecological Security: A Case Study in Wuhan City Circle of China

Exploring the interaction relationship between urbanization and ecological security is the key issue to achieve regional sustainable development. This study used coupling coordination model and vector auto-regression model to comprehensively investigate the interaction relationship between urbanization and ecological security in Wuhan City Circle from 2005 to 2018. The results showed that urbanization quality in Wuhan City Circle increased from 0.1818 in 2005 to 0.4355 in 2018, with an average annual increase rate of 10.74%. The ecological security of Wuhan City Circle decreased from 0.4890 in 2005 to 0.4511 in 2015 and increased from 0.4511 in 2015 to 0.4554 in 2018. The degree of coupling coordination between urbanization and ecological security of Wuhan City Circle presented a circle structure with Wuhan as the center and increasing outward. Additionally, the impulse analysis showed that the increase of urbanization had a significant negative impact on ecological security of Wuhan city, Huangshi city, and Xiaogan city. Meanwhile, the ecological security index of Ezhou city, Tianmen city, Huanggang city, Xiantao city, Xianning city, and Qianjiang city were all positive in early stage after the ecological security was impacted by the increase of urbanization. The analysis of historical data and future trends can provide operable recommendations for urbanization development and ecological security protection through cleaner production and efficient use of natural resources from the aspect of coordinated development.

Landscape Evolution and It's Impact of Ecosystem Service Value of the Wuhan City, China

Rapid urbanization and industrialization and enhanced ecological protection measures have greatly influenced landscape change, which has exacerbated regional landscape competition and conflicts and indirectly affected the supply of ecosystem services. Clarifying the relationship between ecosystem service change and landscape change is useful for understanding the impact of ecosystem conversion on socio-economic development and providing a knowledge base for relevant policy decisions. In this study, we used remote sensing technology to process Landsat TM/ETM+/OLI imageries, combined with transformation analysis and kernel density analysis to study the spatial and temporal characteristics of land use change in Wuhan City from 1980 to 2020. We also estimated the ESV in the region using the improved unit area value equivalent method to reveal the trends of ESV changes in Wuhan. The results showed that land use changes in Wuhan during 1980–2020 occurred mainly in terms of decreases in farmland, forestland, and bare land, as well as increases in built-up land and water bodies. The built-up land was mainly concentrated in the main urban areas, but its area in each suburban area has increased in recent years. In contrast, farmland was mainly distributed in suburban areas, and its area has been decreasing in recent years due to the impact of urban expansion. However, the reduction is compensated for by the reclamation of ecological land such as grassland and forestland, which has aggravated the loss of ecosystem service values in the study area. In addition, human activities such as urban expansion have increased the demand for water resources, while also leading to ecological problems such as water scarcity and water quality degradation, which have caused serious losses to key ecosystem services in Wuhan city. Therefore, in order to alleviate the competition and conflicts in the landscape and mitigate the loss of ecosystem service values in this area, we have proposed some constructive suggestions for future urban planning and water quality improvements in Wuhan. The focus of these suggestions is on controlling the expansion of built-up land, as well as the conservation of ecological land and resource protection. Meanwhile, our findings can also provide reference information for land resource planning and ecological monitoring, and help researchers to understand the contribution of ecosystem service functions in relation to socio-economic development.

The Effects of Land-Use Change/Conversion on Trade-Offs of Ecosystem Services in Three Precipitation Zones

Revealing the spatial differentiation of ecosystem service (ES) trade-offs and their responses to land-use change along precipitation gradients are important issues in the Loess Plateau of China. We selected three watersheds called Dianshi (300 mm < MAP (mean annual precipitation) < 400 mm), Ansai (400 mm < MAP < 500 mm), and Linzhen (500 mm < MAP < 600 mm). A new ES trade-off quantification index was proposed, and quantile regression, piecewise linear regression, and redundancy analysis were used. The results were as follows. (1) Carbon sequestration (TC) and soil conservation (SEC) increased, but water yield (WY) decreased in the three watersheds from 2000 to 2018. (2) The effect of forests on trade-offs was positive in three watersheds, the main effect of shrubs was also positive, but the negative effect appeared in the TC-WY trade-off in Ansai. Grassland exacerbated trade-offs in Dianshi, whereas it reduced trade-offs in Ansai and Linzhen. These effects exhibited respective trends with the quantile in the three watersheds. (3) There were threshold values that trade-offs responded to land-use changes, and we could design land-use conversion types to balance ESs. In general, the water consumption of grass cannot be ignored in Dianshi; shrubs and grass are suitable vegetation types, and forests need to be restricted in Ansai; more forests and shrubs can be supported in Linzen due to higher precipitation, but the current proportions of forests and shrubs are too high. Our research contributes to a better understanding of the response mechanisms of ES trade-offs to land-use changes.

Integrating supply and demand factors for estimating ecosystem services scarcity value and its response to urbanization in typical mountainous and hilly regions of south China

In the process of rapid urbanization, the decline in ecosystems' physical supply value is a direct result of the increasing demands of human development. The ecosystem services value combined with supply and demand factors can be used to obtain the ecosystem services scarcity value (ESSV). These ecosystems with larger ESSVs warrant increased protection, or at the very least a development plan to ensure a balance between their continued existence and human usage. However, urbanization and other developmental effects have often caused the ESSV of those regions to be disregarded, which produces an imbalance in the ecosystem. This paper evaluated the spatial differentiation of ESSV based on heterogeneous units in the Yuebei region, China. Then, a spatial response analysis of the ESSV to urbanization according to the spatial correlation model and Getis-Ord Gi* was conducted. The results showed that the ecosystem service physical supply value declined due to urban sprawl in 1990-2015, but the ESSV increased sharply during the same time with its acceleration being particularly strong after 2000. Areas with higher ESSV were concentrated in the northern region due to a higher prevalence of woodland. Urbanization accelerated significantly after 2000, and it is found that similar tendencies of ESSV and urbanization occurred over the same period. Surprisingly, the ESSV was negatively correlated with urbanization in local regions, and their interaction continued to increase over time. The spatial hotspot map of the ESSV and urbanization also formed an opposite pattern. In addition, the grid number of High-Low and Low-High types is more than half of the total number of aggregated grids. According to the results, understanding the variation in the ESSV clearly due to urbanization and identifying their interaction in local regions can provide a more specific direction for future resource adjustment and ecosystem service improvements.

Identifying mismatches of ecosystem services supply and demand under semi-arid conditions: The case of the Oasis City Urumqi, China

Understanding the balance between supply and demand of ecosystem services (ESs) is helpful for sustainable urban management. However, the interactions among multiple ESs supplies and demands remain under-researched, and ESs supply and demand spatial heterogeneity and correlation characteristics at the city level are rarely studied, especially in arid areas. To fill this gap, we established a comprehensive assessment framework of ESs supply and demand through integrating multi-source remote sensing data, social economy, and policy objectives, for the oasis city of Urumqi, China. The ESs supply-demand mismatches were revealed at the city level, and the spatial relationship between the ESs supply and demand was analyzed using spatial statistics. The results demonstrated that: (1) The total quantity of supply and demand of food provision, carbon sequestration, PM₁₀ removal, and recreation services in Urumqi revealed that the demand was greater than the supply, the deficits being 16.10 × 10⁷  kcal/ha, 6.88 × 10⁴  t/ha, 155.86 kg/ha, and 697.26, respectively. (2) The supply and demand assessment of ESs revealed spatial differences from the city center to the suburbs, which further indicated that there are neighborhood similarities between the supply and demand of ESs. (3) The matching types of ESs supply and demand present obvious spatial heterogeneity, which can be divided into four types: High-high, high-low, low-high, and low-low. Owing to rapid urban development in the inner city, the city center is dominated by low-high, whereas the urban-rural ecotone is characterized by high-low, owing to the higher elevation and water resource advantages in the suburbs. Based on the analysis of the supply, demand, and matching of ESs, economic development and sustainable management policies are proposed for different ecological spaces. Integr Environ Assess Manag 2021;17:1293-1304. © 2021 SETAC.

Identifying and Mapping the Responses of Ecosystem Services to Land Use Change in Rapidly Urbanizing Regions: A Case Study in Foshan City, China

Rapid urbanization has degraded some important ecosystem services and threatens socioeconomic sustainability. Although many studies have focused on the effect of urbanization on ecosystem services, the effect and its threshold have not been well-identified spatially. In this study, we propose a research framework by integrating nighttime light data, the InVEST (Integrated Valuation of Environmental Service and Tradeoffs) model, and a spatial response index to characterize the response of ecosystem services to rapid urbanization. We considered Foshan City as a case study to explore the effect of rapid urbanization on ecosystem services during 2000–2018. Our results showed that rapid urbanization resulted in a 49.13% reduction in agricultural production and a 10.13% reduction in habitat quality. The spatial response index of agricultural production, habitat quality, soil retention, water yield, and carbon sequestration were 14.25%, 2.94%, 0.04%, 0.78%, and 0.07%, respectively. We found that developing urban areas had the highest spatial response index, indicating that this area was the crucial area for future land management. We consider that our research framework can help identify the key areas affected by rapid urbanization. Visualizing the spatial response index and extracting the threshold for different levels of urbanization will be conducive to sustainable urban management and planning.

Assessment of Ecosystem Service Supply, Demand, and Balance of Urban Green Spaces in a Typical Mountainous City: A Case Study on Chongqing, China

Objective measurement of the supply–demand of ecosystem services (ESs) has received increasing attention from recent studies. It reflects the relationship between green spaces and human society. However, these studies rarely assess the mountainous cities. To fill this gap, this study takes a typical mountainous city as a research case to reveal the supply–demand relationship of ecosystem services, then development and management strategies are proposed for different districts according to their spatial differentiation characteristics. Results shows that: (1) there are differences of ESs supply between each district, and supply from Banan District is significantly higher than others. (2) The demands for ES also vary widely, which are higher in the core urban areas. (3) There are different degrees of imbalance between supply and demand in each district. We classified green spaces into four types based on their supply–demand characteristics, and optimization strategies are proposed. We found that most of the districts are lack of ES supply while there is a relatively high demand for ES in Chongqing, and the balance of supply and demand between different districts varies greatly. Our study indicates that targeted urban green spaces strategies for different districts must be considered to adequately optimize ES in mountainous cities.

The Direct and Spillover Effect of Multi-Dimensional Urbanization on PM2.5 Concentrations: A Case Study from the Chengdu-Chongqing Urban Agglomeration in China

The Chengdu-Chongqing urban agglomeration (CUA) faces considerable air quality concerns, although the situation has improved in the past 15 years. The driving effects of population, land and economic urbanization on PM_2.5 concentrations in the CUA have largely been overlooked in previous studies. The contributions of natural and socio-economic factors to PM_2.5 concentrations have been ignored and the spillover effects of multi-dimensional urbanization on PM_2.5 concentrations have been underestimated. This study explores the spatial dependence and trend evolution of PM_2.5 concentrations in the CUA at the grid and county level, analyzing the direct and spillover effects of multi-dimensional urbanization on PM_2.5 concentrations. The results show that the mean PM_2.5 concentrations in CUA dropped to 48.05 μg/m³ at an average annual rate of 4.6% from 2000 to 2015; however, in 2015, there were still 91% of areas exposed to pollution risk (>35 μg/m³). The PM_2.5 concentrations in 92.98% of the area have slowly decreased but are rising in some areas, such as Shimian County, Xuyong County and Gulin County. The PM_2.5 concentrations in this region presented a spatial dependence pattern of "cold spots in the east and hot spots in the west". Urbanization was not the only factor contributing to PM_2.5 concentrations. Commercial trade, building development and atmospheric pressure were found to have significant contributions. The spillover effect of multi-dimensional urbanization was found to be generally stronger than the direct effects and the positive impact of land urbanization on PM_2.5 concentrations was stronger than population and economic urbanization. The findings provide support for urban agglomerations such as CUA that are still being cultivated to carry out cross-city joint control strategies of PM_2.5 concentrations, also proving that PM_2.5 pollution control should not only focus on urban socio-economic development strategies but should be an integration of work optimization in various areas such as population agglomeration, land expansion, economic construction, natural adaptation and socio-economic adjustment.

Impacts of land use and land cover change on the interactions among multiple soil-dependent ecosystem services (case study: Jiroft plain, Iran)

The spatial and temporal distribution pattern is an outstanding feature of the relationship among ecosystem services (ESs) that explains links between human activities and disturbed chemical composition of ecosystems. This study investigated the spatiotemporal variation of land use/cover changes (LUCC) and quantifies the change in four essential ecosystem services with an emphasis on soil (nutrient delivery ratio, carbon storage, crop production, and water yield) and their relationships in the Jiroft plain, Iran, during 1996-2016 through analytical tools including Land Change Modeler, and the Integrated Valuation of Ecosystem Services and Tradeoff. During the 20-year concentrate period, there was a considerable overall gain in cropland (5396 km²) and urban (1787 km²), loss of unused land (5692 km²), water (2088 km²), and forest (1083 km²). As a result of LUCC, while crop production and nutrient delivery ratio showed a rising trend, overall carbon storage and water yield decreased. The spatiotemporal trade-off between carbon storage and crop production, the temporal trade-off between crop production and water yield, and synergy between water yield and crop production were widespread in Jiroft plain. These results showed that the interaction among ESs mutates over time and can be changed under planning and policies. This study will enrich the research of the geographical distribution of ESs interaction in dryland ecosystems to provide practical ecosystem management under local conditions.

Optimizing the Production-Living-Ecological Space for Reducing the Ecosystem Services Deficit

With rapid urbanization and industrialization, China’s metropolises have undergone a huge shift in land use, which has had a profound impact on the ecological environment. Accordingly, the contradictions between regional production, living, and ecological spaces have intensified. The study of the optimization of production-living-ecological space (PLES) is crucial for the sustainable use of land resources and regional socio-economic development. However, research on the optimization of land patterns based on PLES is still being explored, and a unified technical framework for integrated optimization has yet to be developed. Ecosystem services (ES), as a bridge between people and nature, provide a vehicle for the interlinking of elements of the human-land system coupling. The integration of ES supply and demand into ecosystem assessments can enhance the policy relevance and practical application of the ES concept in land management and is also conducive to achieving ecological security and safeguarding human well-being. In this study, an integrated framework comprising four core steps was developed to optimize the PLES in such a way that all ecosystem services are in surplus as far as possible. It was also applied to a case study in the middle and lower reaches of the Yellow River Basin. A regression analysis between ES and PLES was used to derive equilibrium thresholds for the supply and demand of ES. The ternary phase diagram method was used to determine the direction and magnitude of the optimization of the PLES, and finally, the corresponding optimization recommendations were made at different scales.

Exploring Spatial Variations in the Relationships between Landscape Functions and Human Activities in Suburban Rural Communities: A Case Study in Jiangning District, China

There is a complicated and contradictory relationship between landscape functions and human activities, especially in the suburban rural communities of metropolises. Previous studies focused on human interference to landscape function, ignoring the impact of landscape functions on human activities. Hence, the present study is focused on the impact of landscape function (based on ecosystem services) on human activities in suburban rural communities of China. The study evaluated the intensity of human activities based on big data; furthermore, the authors analyzed the spatial distribution characteristics through spatial autocorrelation, and probed into the spatial variations in the relationship between human activities and landscape functions using ordinary least squares (OLS) and geographically weighted regression (GWR) models. The result indicates that there are obvious spatial distribution differences in the intensity of human activities in suburban rural communities; that is, the intensity decreases from the inner to the outer suburban areas. Positive influencing factors of human activities are construction area, bus station, road network density, and leisure entertainment, among which, construction area is the principal driver; cultural heritage, hydrological regulation, and provision of aesthetics are negatively or positively correlated with human activities in various regions. The results offer insights for the sustainable development of rural environment in suburban areas and the big data-driven rural research.

The Driving Influence of Multi-Dimensional Urbanization on PM2.5 Concentrations in Africa: New Evidence from Multi-Source Remote Sensing Data, 2000-2018

Africa’s PM_2.5 pollution has become a security hazard, but the understanding of the varying effects of urbanization on driven mechanisms of PM_2.5 concentrations under the rapid urbanization remains largely insufficient. Compared with the direct impact, the spillover effect of urbanization on PM_2.5 concentrations in adjacent regions was underestimated. Urbanization is highly multi-dimensional phenomenon and previous studies have rarely distinguished the different driving influence and interactions of multi-dimensional urbanization on PM_2.5 concentrations in Africa. This study combined grid and administrative units to explore the spatio-temporal change, spatial dependence patterns, and evolution trend of PM_2.5 concentrations and multi-dimensional urbanization in Africa. The differential influence and interaction effects of multi-dimensional urbanization on PM_2.5 concentrations under Africa’s rapid urbanization was further analyzed. The results show that the positive spatial dependence of PM_2.5 concentrations gradually increased over the study period 2000–2018. The areas with PM_2.5 concentrations exceeding 35 μg/m³ increased by 2.2%, and 36.78% of the African continent had an increasing trend in Theil–Sen index. Urbanization was found to be the main driving factor causing PM_2.5 concentrations changes, and economic urbanization had a stronger influence on air quality than land urbanization or population urbanization. Compared with the direct effect, the spillover effect of urbanization on PM_2.5 concentrations in two adjacent regions was stronger, particularly in terms of economic urbanization. The spatial distribution of PM_2.5 concentrations resulted from the interaction of multi-dimensional urbanization. The interaction of urbanization of any two different dimensions exhibited a nonlinear enhancement effect on PM_2.5 concentrations. Given the differential impact of multi-dimensional urbanization on PM_2.5 concentrations inside and outside the region, this research provides support for the cross-regional joint control strategies of air pollution in Africa. The findings also indicate that PM_2.5 pollution control should not only focus on urban economic development strategies but should be an optimized integration of multiple mitigation strategies, such as improving residents’ lifestyles, optimizing land spatial structure, and upgrading the industrial structure.

Linking Ecosystem Service Supply–Demand Risks and Regional Spatial Management in the Yihe River Basin, Central China

The continuous supply of ecosystem services is the foundation of the sustainable development of human society. The identification of the supply–demand relationships and risks of ecosystem services is of considerable importance to the management of regional ecosystems and the effective allocation of resources. This paper took the Yihe River Basin as the research area and selected water yield, carbon sequestration, food production, and soil conservation to assess changes in the supply and demand of ecosystem services and their matching status from 2000 to 2018. Risk identification and management zoning were also conducted. Results show the following: (1) The spatial distribution of the four ecosystems service supply and demand in the Yihe River Basin was mismatched. The food production supply levels in the middle and lower reaches and the upstream water yield, carbon sequestration, and soil conservation supply levels were high. However, most of the areas with high demand for ecosystem services were concentrated downstream. (2) From 2000 to 2018, the supply of water yield and carbon sequestration in the Yihe River Basin decreased, while that of food production and soil conservation increased. The demand for the four ecosystem services also increased. (3) Water yield faced considerable supply–demand risks. Fifty percent of the sub-basins were at a high-risk level, and the risk areas were concentrated in the middle and lower reaches. The three remaining services were mainly at low-risk levels. The Yihe River Basin was divided into eight types of supply–demand risk spatial management zones based on the ecosystem service supply and demand levels, which will help promote refined regional ecosystem management and sustainable development. The supply and demand assessment of ecosystem services from a risk perspective can integrate the information of natural ecosystems and socio-economic systems and provide scientific support for watershed spatial management.

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.

Effects of Urbanization on Ecosystem Services in the Shandong Peninsula Urban Agglomeration, in China: The Case of Weifang City

Ecosystem services are the material basis of economic and social development, and play essential roles in the sustainable development of ecosystems. Urbanization can remarkably alter the provision of ecosystem services. Most studies in this area have focused on densely populated metropolises with poor ecological environments, while comparatively few studies have focused on cities with low ecological pressures. Therefore, to avoid continuing to engage in the repetitive pattern of destroying first and rehabilitating later, quantitative analyses of urbanization and ecosystem services should be carried out in representative cities. In this study, based on partial least squares-discriminant analysis, kernel density estimation, and correlation analysis, we quantitatively evaluated the impact of urbanization on ecosystem services in Weifang city. The Data Center for Resources and Environmental Sciences at the Chinese Academy of Sciences and the Institute of Geographic Sciences and Natural Resources Research provided remote sensing data on land use, the gross domestic production (GDP), population data, and ecosystem services. The results were as follows: (1) The variation in population, GDP, and built-up areas consistently increased throughout the study period, whereas the ecosystem service values (ESVs) decreased; (2) food production, raw material production, nutrient cycle maintenance, and soil conservation were decisive ecosystem services that led to vast reductions in ESVs during the process of urbanization; and (3) the negative correlation coefficient between built-up areas and ecosystem services was greater than that between the population or GDP and ecosystem services, which indicated that the impacts of population and economic urbanization on ecosystem services lagged behind the impact of land urbanization. This study provides references for fully recognizing the ecological effects of urbanization, and make suggestions regarding the application of ecosystem services in sustainable development.

Integrating Ecological Assessments to Target Priority Restoration Areas: A Case Study in the Pearl River Delta Urban Agglomeration, China

The identification and management of ecological restoration areas play important roles in promoting sustainable urban development. However, current research lacks a scientific basis for the scope and scale of ecological restoration. Further, the absence of a framework to assess policy goals and public preferences that leads to identification of ecological restoration areas across the science-policy interface is difficult, and the existing frameworks’ performance has little applicability. We proposed a transdisciplinary framework to combine ecological quality, ecological health, and ecosystem services as an assessment endpoint to identify priority restoration areas. Further, we classified the ecological restoration areas on a township scale by K-means. Based upon policy goals and public preferences of the Pearl River Delta urban agglomeration, we chose air quality, biodiversity, soil fragility, recreation quality, ecosystem vigor, landscape metrics, and the water supply ecosystem service as elements of the evaluation system. This study showed that priority restoration areas accounted for 10.8% of the urban agglomeration area and classified township, largely in the difference between natural and semi-natural ecosystems and the human environment. Policymakers can use this framework comprehensively and flexibly to identify and classify ecological restoration areas to achieve policy goals and fulfil public preferences.

Spatial identification and determinants of trade-offs among multiple land use functions in Jiangsu Province, China

Understanding the relationships among multiple land use functions (LUFs) is crucial for land-based spatial planning that can guide targeted land use policy-making in complex socio-ecological systems. However, few studies concerned the interactions among various LUFs integrating the issues of economy, environment, and society at a fine scale. In this study, we quantified 12 LUFs using a geospatial model and statistical analysis at the grid scale in Jiangsu Province. Then, we identified the relationships among three primary LUFs-agricultural production function (APF), urban-rural living function (ULF), and ecological maintenance function (EMF)-and further explored the determinants of LUF trade-offs aimed to provide a reference for policy-makers to make decisions in future land use planning and management. The results revealed that the high trade-off areas for APF and ULF are mainly distributed in central and northern Jiangsu, and the trade-offs for both APF-EMF and ULF-EMF were higher in the area covered with water and forest. The determinants of LUF trade-offs mainly refers to land use/land cover, potential evapotranspiration, and vegetation coverage ratio. Moreover, landscape configuration metrics and distance to the nearest county and nearest road also have remarkable impacts on the trade-offs of APF-EMF and ULF-EMF. Finally, we proposed that the concepts of LUF trade-offs should be incorporated into the processes of delineating boundaries for urban growth, farmland, and natural areas. We also propose that land consolidation projects should be implemented in an orderly manner to alleviate LUF trade-offs.

Impacts of Urban Expansion Forms on Ecosystem Services in Urban Agglomerations: A Case Study of Shanghai-Hangzhou Bay Urban Agglomeration

Exploring impacts of urban expansion on ecosystem services has become a hot topic for regional sustainable development, while analyzing the ecological effects of urban expansion forms under different expansion intensities and city sizes is relatively rare. Therefore, taking a typical urban agglomeration, Shanghai-Hangzhou Bay Urban Agglomeration, as a case study, this study first analyzed the dynamics of urban expansion forms (leapfrogging, edge-expansion, and infilling) and four critical ecosystem services (carbon sequestration, food supply, habitat quality, and soil retention) in three periods from 1990 to 2019. The multiple linear regression model and zonal statistics analysis model were used to quantitatively identify the impacts of urban expansion forms on ecosystem services, taking into account different expansion intensities and city sizes. The results showed that the urban expansion trend in the study area experienced a morphological change from integration to diffusion and then to integration in 1990–2019; edge-expansion was the dominant expansion form. Food supply decreased continuously while other ecosystem services had fluctuating changes, and they all had spatial heterogeneity. The leapfrogging, edge-expansion, and infilling all had negative impacts on ecosystem services, and among them, the edge-expansion intensity had the highest influence degree in the early expansion, and the leapfrogging intensity occupied the dominant position in all influences with the expansion of urban scales. For different city sizes, the impact of edge-expansion in large-scale cities was greater than in small-scale cities in the early expansion, and the impact of leapfrogging in large-scale cities exceeded the edge-expansion in the subsequent expansion. These findings will help further understand the influential mechanisms between urban expansion and ecosystem services and provide a scientific basis for formulating reasonable urban planning.

Urbanization pressures alter tree rhizosphere microbiomes

The soil microbial community (SMC) provides critical ecosystem services including organic matter decomposition, soil structural formation, and nutrient cycling. Studies suggest plants, specifically trees, act as soil keystone species controlling SMC structure via multiple mechanisms (e.g., litter chemistry, root exudates, and canopy alteration of precipitation). Tree influence on SMC is shaped by local/regional climate effects on forested environments and the connection of forests to surrounding landscapes (e.g., urbanization). Urban soils offer an ideal analog to assess the influence of environmental conditions versus plant species-specific controls on SMC. We used next generation high throughput sequencing to characterize the SMC of specific tree species (Fagus grandifolia [beech] vs Liriodendron tulipifera [yellow poplar]) across an urban-rural gradient. Results indicate SMC dissimilarity within rural forests suggests the SMC is unique to individual tree species. However, greater urbanization pressure increased SMC similarity between tree species. Relative abundance, species richness, and evenness suggest that increases in similarity within urban forests is not the result of biodiversity loss, but rather due to greater overlap of shared taxa. Evaluation of soil chemistry across the rural-urban gradient indicate pH, Ca⁺, and organic matter are largely responsible for driving relative abundance of specific SMC members.

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

Understanding the relationships between ecosystem services (ES) and their underlying socioecological drivers is essential for forming the efficient management decisions of ecosystems. We use a large watershed area as a case-study to analyze trade-offs/synergies and bundles of ESs and identify the associated socioecological variables (SEVs). This study assessed the supply of 7 ES indicators, namely, three provisioning services (crop production, livestock production, and industrial production), three regulating services (water conservation, soil conservation, and carbon sequestration), and one cultural service (recreation), across 65 municipalities in the Yellow River Basin (YRB) in China. We analyzed the paired trade-offs/synergies using Spearman's coefficient and identified the ES bundles (ESBs) by applying principal component analysis and K-means clustering. Subsequently, we detected the SEVs that affect the ES supply using the geo-detector model and characterized the associations between ESBs and socioecological clusters according to the spatial overlap. The results demonstrated that the synergies between ESs substantially exceeded the trade-offs, among which the strongest synergies were between the crop production and the livestock production, and both responded strongly to the cropland and the population density. Trade-offs were identified between provisioning services and soil conservation. Municipalities were grouped into three ESBs in the YRB. The ESB, which was dominated by provisioning ESs, was associated with areas where cropland, precipitation and socioeconomic conditions were all important, and the regulation of ESB was linked to regions with distinct ecological characteristics. We also identified an ESB that was dominated by carbon sequestration, as determined by extensive grassland and bare land. The land use/land cover strongly affected the characteristics of the ESBs. The findings can be used by land managers to identify areas in which ESs are dominant, to determine the associations of these compositions of the ESs with SEVs, and to support the formulation of optimal ES management in large-scale basins.