Ecosystem services (ES) can be defined as the various benefits—including products and services—that peoples obtain from ecosystems that contribute to human well-being or maintain the global life-supporting systems [1
]. In the last several decades, high demands for natural resources such as food, fuel, and shelter arising from population growth, rapid urbanization, and economic development have redoubled human efforts to enhance certain ecosystem services [4
], often at the expense of others [5
]. As a result, human activities have changed global ecosystems with unprecedented intensities and rates. According to Millennium Ecosystem Assessment (MEA), over 60% of global ecosystem services have degraded and therefore affected the provision of current and future ecosystem services [2
]. Among all human activities, land-use change is one of the major determinants of the supply of ES [2
], as certain ES are closely correlated to specific types of land use [1
]; for example, timber and climate regulation are mostly provided by forests [11
]. Therefore, the relationship between land-use change and ES is receiving extensive attention by scientists and policymakers worldwide.
In this context, several studies have made progress in elucidating ES supply changes and the effects of land-use changes [12
]. The influences of land-use changes on ES vary widely across different socioeconomic backgrounds and spatial or temporal scales [5
]. Recent research has demonstrated that the diversity of social demands and the spatial heterogeneity of environment result in more complex and constantly changing interactions among multiple ecosystems’ services [17
]. For instance, the increase of cultivated land for food leads to reductions in carbon storage and increased risk of soil erosion, while urbanization—which can result in reforestation and improved human living environments—can disrupt surface water balance and influence regional climates [19
]. These finding exemplify how promotion of one particular ES by land-use change often leads to gains or losses of other ES, suggesting the existence of synergies or trade-offs in the provisioning of ES [21
]. Although they are not always obvious, synergies or trade-offs among multiple ES are taking place all the time, which are often poorly understood and thus may cause unintended environmental consequences. Therefore, reassessing our assumptions surrounding land-use change with greater focus on the trade-offs among multiple ES driven by the interactions among land-use types will provide a theoretical basis for land-use managers and policymakers.
The relationship between ES and land-use changes highlights the importance of ES in guiding land-use planning and ecosystem management strategies to promote sustainability [23
]. Specifically, ES assessments can be integrated into land-use planning in two modes; one is used as a criterion in land-use scheme development. For instance, [26
] utilized the land-use optimization model FUTURES that is based on the bottom-up Cellular Automata (CA) simulation and the state transformation of micro-level cells to examine the impact of three urban growth scenarios on ES. The other is as an assessment, comparison, and selection among multiple land-use schemes under different scenarios. For instance, [23
] predicted the urban expansion and ES dynamics in Beijing from 2013 to 2040 under different development scenarios. They found that decreases of some critical ecosystem services would be significantly lower under a scenario to conserve ecosystem services than those under the business-as-usual scenario. Moreover, [27
] evaluated the impacts of different urban growth scenarios on four ES, to determine the degree to which configuration of urbanization and the development of natural land-use/land-cover impacts these services and trade-offs over 25 years in Western North Carolina. However, due to the uncertainty of alternative future land-use dynamics relative to socioeconomic and natural environmental driving forces [9
], assessing how the ecosystem services and their trade-offs and synergies will temporally respond to future land-use changes remains challenging. Although spatiotemporal land-use scenario simulations are an effective and reproducible tool in projecting future land-use trajectories and support future land-use policy decisions [28
], most of these models can only simulate the dynamics of one individual land-use class, as different land-use/land-cover changing processes occur simultaneously and interact with each other in most cases. Thus, we propose an approach that interactively integrates the Markov model (Quantitative simulation) with the GeoSOS-FLUS model (Spatial arrangement) for a multiple land-use dynamic simulation, which couples both human-related and natural environmental effects, using an elaborate design of the interactions and competition among different land-use types under alternative scenarios.
Over the past few decades, rapid economic development and population growth, accompanied by drastic land-use changes, have triggered ecological crises like water shortages, soil erosion, and losses of high-quality cultivated land, which are among the most serious problems that Beijing faces—especially in the western and northern mountainous areas [30
]. Although there has been the protection of laws for the nature reserves and other legally binding of ecological zones, they are not respected and are seriously threatened in the current land-use policies. To address these problems, local governments initiated a series of ecological protection plans, including the “Red Lines for Ecological Protection in Beijing”, as well as the “13th Five-Year Plan of Environmental protection and Ecological construction in Beijing”. Here, we use the ecological conservation area of Beijing, an area with intense human activities and ecologically vulnerable areas, as the study area. In this area, the complex interaction between human activities and the natural environment poses a major challenge to the sustainable provision of ES. Therefore, we first present the future land-use simulation (GeoSOS-FLUS) model and Markov model to simulate future land use under three alternative scenarios, i.e., Business as Usual (BAU), Rapid Economic Development (RED), and Ecological Land Protection (ELP) in the ecological conservation area. Then, we selected the InVEST (Integrated Valuation of Ecosystem Services and Trade-Offs) model that was developed by the Natural Capital Project team of the United States and has been widely used in evaluating the quantity of ecosystem services and to support ecosystem management and decision-making. Specifically, we focus on three main objectives: (1) modeling the current and future dynamics of the ES—carbon storage (CS), flood regulation (FR), and soil conservation (SC); (2) quantifying the effects of land-use change on these services and the trade-offs among them; (3) providing appropriate indicators to support the identification of rational land-use strategies, to improve ES management for our study area.
In this study, we explored how land-use changes would affect ecosystem services, including carbon storage, flood regulation, and soil conservation, from 2015 to 2030, under three different scenarios. According to our results, the significant increase of built-up land is mainly at the expense of the water bodies and cultivated land in 2030, under the BAU and RED scenarios. The ELP scenario would show the largest increase in forest land, and the change of cultivated land and built-up land is relatively stable compared with the other two scenarios, due to the strict protection policy on ecological land. As a result, the ELP scenario would show the highest amount of carbon storage, flood regulation, and soil conservation. The cultivated land and forest land converted to built-up land would promote soil conservation, but trigger greater loss of carbon storage and flood regulation capacity. We also found trade-offs or synergies among ecosystem services in which carbon storage would show significant positive correlation with soil conservation from 2015 to 2030. Based on these findings, we propose four major land-use strategies, including fully utilizing urban land, farmland protection, tree planting, and utilization of water resources to achieve sustainable use of ecosystem services in the ecological conservation area.