Time series analysis of PM2.5 pollution risk based on the supply and demand of PM2.5 removal service: a case study of the urban areas of Beijing.

Demonstrating the temporal changes in PM2.5 pollution risk in regions facing serious PM2.5 pollution problems can provide scientific evidence for the air pollution control of the region. However, research on the variation of PM2.5 pollution risk on a fine temporal scale is very limited. Therefore, we developed a method for quantitative characterizing PM2.5 pollution risk based on the supply and demand of PM2.5 removal services, analyzed the time series characteristics of PM2.5 pollution risk, and explored the reasons for the temporal changes using the urban areas of Beijing as the case study area. The results show that the PM2.5 pollution risk in the urban areas of Beijing was close between 2008 and 2012, decreased by approximately 16.3% in 2016 compared to 2012, and further decreased by approximately 13.2% in 2021 compared to 2016. The temporal variation pattern of the PM2.5 pollution risk in 2016 and 2021 showed significant differences, including an increase in the number of risk-free days, a decrease in the number of heavily polluted days, and an increase in the stability of the risk day sequence. The significant reduction in risk level was mainly attributed to Beijing's air pollution control measures, supplemented by the impact of COVID-19 control measures in 2021. The results of PM2.5 pollution risk decomposition indicate that compared to the previous 2 years, the stability and predictability of the risk variation in 2016 increased, but the overall characteristics of high risk from November to February and low risk from April to September did not change. The high risk from November to February was mainly due to the demand for coal heating during this period, a decrease in PM2.5 removal service supply caused by plant leaf fall, and the common occurrence of temperature inversions in winter, which hinders the diffusion of air pollutants. This study provides a method for the analysis of PM2.5 pollution risk on fine temporal scales and may provide a reference for the PM2.5 pollution control in the urban areas of Beijing.

Identifying ecological security patterns based on the supply, demand and sensitivity of ecosystem service: A case study in the Yellow River Basin, China.

Ecological security is the basis for ecosystems to provide various ecosystem services (ESs) to humans. Identifying ecological security patterns (ESPs) is an effective approach to determine the priority conservation areas and ensure regional ecological security. However, most previous studies on ESPs were based mainly on the supply of ESs, while the demand and sensitivity of ESs were not fully considered. In this study, a comprehensive ESP identification framework was developed by integrating the supply, demand and sensitivity of ESs with the fuzzy multicriteria decision-making and circuit theory. Taking the Yellow River Basin (YRB) as a case study, our results show that the ecological sources (139,633 km2 or 17.3%) of the YRB were located mainly in the transition area between the Qinghai-Tibet Plateau and Loess Plateau, and in the Qinling Mountains and eastern plains; these areas reliably exhibited high conservation efficiency and low decision-making risk and tradeoff levels. However, the northern and western YRB had few ecological sources due to mismatches among the supply, demand and sensitivity of ESs. Based on circuit theory, ecological corridors (36,905 m and 76,878 km2) effectively connected the western, southern and eastern parts of the YRB. These ecological sources and corridors were both dominated by grassland, forest and cropland. However, ten pinch points, primarily covered by cropland, were also recognized in the eastern YRB and should be considered as priority areas for ecological conservation. Moreover, our results indicate that this comprehensive ESP identification framework could provide useful guidance to decision-makers for maintaining ESs and ecological conservation.

Linking Ecosystem Service Supply and Demand to Evaluate the Ecological Security in the Pearl River Delta Based on the Pressure-State-Response Model.

The increase in population and economic development has made environmental issues more serious and threatens regional ecological security and sustainable development. Currently, most indicators in the related research field of ecological security tend to be socio-economic and neglect depicting the state of the ecosystems. This study, therefore, assessed the ecological security by constructing the evaluation index system embedded in the ecosystem service supply and demand based on the pressure-state-response model and identified the key obstacles to ecological security in the Pearl River Delta from 1990 to 2015. Our results showed that soil retention, carbon sequestration, and water yield increased with fluctuation except for grain production and habitat quality. The grain demand, carbon emission, and water demand increased sharply by 10.1%, 769.4%, and 17.5%, respectively. The ecosystem service supply areas were mainly located in the low hills, while the demand regions were mainly in the low plain areas. The ecological security index's decline in vitality was caused by the decrease in the pressure index, indicating that the ecological security showed an inevitable deterioration and increased pressure on the ecosystem. During the study period, the source of the five key obstacle factors changed from the state layer and response layer to the pressure layer. The accumulative degree of the five top obstacle factors was above 45%. Therefore, governments should grasp the key indicators to improve ecological security as this study provides the theoretical basis and scientific information for sustainable development.

Spatial and temporal patterns of supply and demand risk for ecosystem services in the Weihe River Main Stream, NW China.

The rapid development of society and economy in the post-industrial era has exacerbated the spatial matching contradiction between the demand of humans and the supply of the natural environment, while ecosystem service (ES) as a bridge linking nature and society, identifying and assessing its supply-demand risk, was beneficial to ecosystem management and promoted regional high-quality development. Based on the data of multi-source remote sensing and statistics, the supply and demand levels of four ESs, which contain food supply, carbon storage, soil conservation, and water yield in the main stem of the Weihe River in 2000, 2010, and 2020, were quantitatively measured. The spatial and temporal analysis of the supply, demand, and supply-demand ratio of each service was carried out using spatial mapping. The spatio-temporal pattern of the supply-demand risk was recognized by the method of spatial overlay, which means overlaying the supply and demand for material quality, ratio, trend, and the degree of trade-off coordination together between each service. The results showed that (1) the demand for water yield decreased slightly while the demand for food and the supply of carbon storage remained stable. In addition, the supply and demand of other services showed an upward trend. (2) The spatial distribution of the supply-demand ratio of each service shows "high in the south and low in the north" and "high in the east and low in the west," among which the supply-demand ratio of carbon storage is decreasing. (3) The overall supply-demand risk of soil conservation in the study area is low with characteristics of small range and high degree, the risk distribution characteristics of the other services are high in the east and low in the west, and the risk is high in the city center and low around. Otherwise, the supply-demand risk of food supply showed a downward trend, the risk of carbon storage showed an upward trend, the risk of soil conservation remained stable, and the risk of water yield showed a significant downward trend. Based on static supply-demand risk identification, this study assesses supply-demand risk over two periods and analyzes the trend of supply-demand risk changes over time. It clarifies the extent and direction of supply-demand risk shifts, as well as provides improved theoretical support for ecosystem service management.

Spatiotemporal Differentiation and Balance Pattern of Ecosystem Service Supply and Demand in the Yangtze River Economic Belt.

Analyzing the supply and demand of ecosystem services and the regional balance pattern is an important basis for improving the ecological management level. Taking the Yangtze River economic belt as the study area, the spatiotemporal characteristics and balance pattern of ecosystem service supply and demand are quantitatively revealed based on equivalent factors, supply and demand balance modeling and quantile regression. The results show that: (1) the ecosystem services value in the research area experienced a change process of "increase-decrease-increase" from 2000 to 2020. The ecological service value of cultivated land and grassland presented a continuous decline, with decreases of 20.446 billion and 4.53 billion yuan, respectively, in the past 20 years, with reduction rates of -4.82% and -3.98%, respectively. (2) The demand for ecosystem services showed an unbalanced and phased growth trend. The total demand for ecosystem services showed heterogeneity and agglomeration effects in space. High demand and higher demand areas are mainly distributed in the regions with relatively developed population and economy, including Yangtze River Delta urban agglomeration, "Changsha-Zhuzhou-Xiangtan" urban agglomeration, Poyang Lake Plain, Jianghan Plain and Chengdu Plain. (3) The overall pattern of the supply-demand balance of ecosystem services has changed little; however, there have also been significant changes in certain areas in individual years.

Review on supply and demand of ecosystem service and the construction of systematic framework.

The supply and demand of ecosystem services are related to both natural ecosystems and socio-economic systems. The research on the supply and demand of ecosystem services would help enhance ecosystem management and achieve optimal allocation of resources, which ensures regional ecological security and sustainable development of socio-economic. Based on a systematic review of international literature, we comprehensively reviewed the conceptual connotation, evaluation metho-ds, and practical application of ecosystem service supply and demand. Although relatively abundant investigations have been conducted from the perspective of theoretical development, they are still scattered and lacking a coherent research framework. Based on expanding the scope of research on the supply and demand of ecosystem service, we constructued a research framework that referred to "qualitative-positioning-quantitative-policymaking" in accordance with the research pattern of "theory-methodology-practice". To promote the theoretical and practical research on the supply and demand of ecosystem service, future research needs to focus on the spatial delivery mechanism, strengthen the research on quantitative methods, deepen the management and application practice, and establish the evaluation mechanism of ecosystem service supply and demand application.

Considering landscape-level processes in ecosystem service assessments.

The provision of ecosystem services is inherently spatial. Landscape structure affects service provision through multiple landscape-level processes, such as fragmentation, edge and connectivity effects. These processes can affect areas of ecosystem service supply and demand, and the flows linking those areas. Despite the emergence of sophisticated spatial ecosystem service assessments in the last two decades, we show through a literature review that landscape-level processes are still rarely considered in a comprehensive way. Even when they are considered, landscape effects are mostly limited to landscape composition, and configuration effects are underrepresented. Furthermore, most studies infer ecosystem service provision by only evaluating supply, ignoring demand and flows. Here we present a simple conceptual framework that illustrates how to incorporate landscape-level processes in the assessment of the different components of the service provision chain (supply, demand and flows). Using simulations, we evaluated how estimations of ecosystem service provision change when considering different landscape processes and discussed the implications of disregarding landscape effects. However, to fully implement the framework, a series of challenges linked to mapping and quantifying supply and demand, defining adequate scales of analysis, measuring flows, and parameterizing models for different types of services, still need to be overcome. To promote an adequate use and management of ecosystem services, it is essential to better incorporate landscape processes in ecosystem service assessments. This will lead to more quantitatively accurate and spatially precise estimates.

Temporal patterns in ecosystem services research: A review and three recommendations.

Temporal aspects of ecosystem services have gained surprisingly little attention given that ecosystem service flows are not static but change over time. We present the first systematic review to describe and establish how studies have assessed temporal patterns in supply and demand of ecosystem services. 295 studies, 2% of all studies engaging with the ecosystem service concept, considered changes in ecosystem services over time. Changes were mainly characterised as monotonic and linear (81%), rather than non-linear or through system shocks. Further, a lack of focus of changing ecosystem service demand (rather than supply) hampers our understanding of the temporal patterns of ecosystem services provision and use. Future studies on changes in ecosystem services over time should (1) more explicitly study temporal patterns, (2) analyse trade-offs and synergies between services over time, and (3) integrate changes in supply and demand and involve and empower stakeholders in temporal ecosystem services research.

Global vulnerability of soil ecosystems to erosion.

CONTEXT: Soil erosion is one of the main threats driving soil degradation across the globe with important impacts on crop yields, soil biota, biogeochemical cycles, and ultimately human nutrition. OBJECTIVES: Here, using an empirical model, we present a global and temporally explicit assessment of soil erosion risk according to recent (2001-2013) dynamics of rainfall and vegetation cover change to identify vulnerable areas for soils and soil biodiversity. METHODS: We used an adaptation of the Universal Soil Loss Equation together with state of the art remote sensing models to create a spatially and temporally explicit global model of soil erosion and soil protection. Finally, we overlaid global maps of soil biodiversity to assess the potential vulnerability of these soil communities to soil erosion. RESULTS: We show a consistent decline in soil erosion protection over time across terrestrial biomes, which resulted in a global increase of 11.7% in soil erosion rates. Notably, soil erosion risk systematically increased between 2006 and 2013 in relation to the baseline year (2001). Although vegetation cover is central to soil protection, this increase was mostly driven by changes in rainfall erosivity. Globally, soil erosion is expected not only to have an impact on the vulnerability of soil conditions but also on soil biodiversity with 6.4% (for soil macrofauna) and 7.6% (for soil fungi) of these vulnerable areas coinciding with regions with high soil biodiversity. CONCLUSIONS: Our results indicate that an increasing proportion of soils are degraded globally, affecting not only livelihoods but also potentially degrading local and regional landscapes. Similarly, many degraded regions coincide with and may have impacted high levels of soil biodiversity.

Advancing Systematic Conservation Planning for Ecosystem Services.

Conservation and sustainable management activities are critical for enhancing ecosystem services. Systematic conservation planning (SCP) is a spatial decision support process used to identify the most cost-effective places for intervention and is increasingly incorporating ecosystem services thinking. Yet, there is no clear guidance on how to incorporate ecosystem service components (i.e., supply, demand, and flow) for multiple beneficiaries into the decision problem underpinning SCP. As such, conservation plans may fall short of maximizing benefits for both people and nature. We propose a benefit-based approach to integrate ecosystem service components into SCP that uses the principles of decision theory. Our approach will improve the likelihood that ecosystem service benefits are enhanced in spatial planning applications.

Towards a Threat Assessment Framework for Ecosystem Services.

How can we tell if the ecosystem services upon which we rely are at risk of being lost, potentially permanently? Ecosystem services underpin human well-being, but we lack a consistent approach for categorizing the extent to which they are threatened. We present an assessment framework for assessing the degree to which the adequate and sustainable provision of a given ecosystem service is threatened. Our framework combines information on the states and trends of both ecosystem service supply and demand, with reference to two critical thresholds: demand exceeding supply and ecosystem service 'extinction'. This framework can provide a basis for global, national, and regional assessments of threat to ecosystem services, and accompany existing assessments of threat to species and ecosystems.

Priorities to Advance Monitoring of Ecosystem Services Using Earth Observation.

Managing ecosystem services in the context of global sustainability policies requires reliable monitoring mechanisms. While satellite Earth observation offers great promise to support this need, significant challenges remain in quantifying connections between ecosystem functions, ecosystem services, and human well-being benefits. Here, we provide a framework showing how Earth observation together with socioeconomic information and model-based analysis can support assessments of ecosystem service supply, demand, and benefit, and illustrate this for three services. We argue that the full potential of Earth observation is not yet realized in ecosystem service studies. To provide guidance for priority setting and to spur research in this area, we propose five priorities to advance the capabilities of Earth observation-based monitoring of ecosystem services.

Reframing landscape fragmentation's effects on ecosystem services.

Landscape structure and fragmentation have important effects on ecosystem services, with a common assumption being that fragmentation reduces service provision. This is based on fragmentation's expected effects on ecosystem service supply, but ignores how fragmentation influences the flow of services to people. Here we develop a new conceptual framework that explicitly considers the links between landscape fragmentation, the supply of services, and the flow of services to people. We argue that fragmentation's effects on ecosystem service flow can be positive or negative, and use our framework to construct testable hypotheses about the effects of fragmentation on final ecosystem service provision. Empirical efforts to apply and test this framework are critical to improving landscape management for multiple ecosystem services.