A critical review of Gross ecosystem product accounting in China: Status quo, problems and future directions

At least two accounting systems for Gross Ecosystem Product (GEP) are needed

Gross Ecosystem Product (GEP) denotes the aggregate value of ecosystem services (ESs) supplied by all ecosystem types within an accounting area for a given accounting period in monetary units and represents one of the multiple types of measures of ES values. The value of each ES is typically calculated by multiplying the ES's quantity by the ES's unit value that may be reflected by various proxies, such as market price, replacement cost, and avoided damage cost. As an economic, ecological, or environmental indicator, GEP should be calculated based on certain standards, allowing for comparison over time and across regions. While many standards, including which ESs to account for and what proxies for ESs' values to use, should be unified to improve the comparability of GEP, this standardization does not mean a single GEP accounting system is sufficient to achieve multiple goals. Instead, at least two accounting systems with different applicability and levels of sophistication are needed. (1) To assess environmental status, ecosystems' capacities to provide ESs, and the performance of environmental governance, there should be a simplified system that accounts for both realized ESs (actually received by humans) and potential ESs (beyond actual humans demands) and adopts a nationwide unified constant unit value of each ES. (2) To assess ESs' actual contributions to socioeconomic development and human well-being, there should be a more sophisticated system that accounts for realized ESs only and adopts a dynamic unit value of each ES. This dynamic unit value should be adjusted to fit local socioeconomic and ecological contexts, consider the tipping point or threshold in each ES's quantity, and reflect the diminishment or increment in the marginal utility of each ES.

Analyzing spatio-temporal changes and trade-offs/synergies of gross ecosystem product based on water-energy-food nexus

The value of the ecosystem's ultimate goods and services for human welfare and long-term economic and social development is known as the gross ecosystem product (GEP). For the study of GEP accounting, the suggested water-energy-food (WEF) nexus offers a fresh viewpoint. This work aims to build a GEP accounting index system based on WEF, investigate its spatio-temporal evolution characteristics, and assess trade-offs and synergies between and within the water, energy, and food subsystems. Using the Three Gorges Reservoir area (TGRA) as an illustration, the findings revealed that, firstly, the comprehensive benefit of GEP based on WEF showed an upward trend in TGRA. Still, it was worth noting that the total production of the food ecosystem decreased. Secondly, the GEP based on WEF in five periods showed a spatial pattern of "high east and west, low middle." Thirdly, the Pearson correlation coefficient indicated that the GEP trade-off relationships based on WEF were dominant in TGRA, with the strongest trade-offs between AQV, SCV, APV, and LEV. In addition, in bivariate local spatial autocorrelation, the value of the six ecosystem service function relationships was dominated by the trade-off relationship, and the distribution of trade-offs and synergies showed significant heterogeneity at the county scale in the TGRA. Finally, hot spot analysis showed that the hot spots of the gross water and energy ecosystem products were scattered in the tail area of the study area. In contrast, the hot spots of the gross food ecosystem product were concentrated in the belly region. The findings of this study provided a basis for the scientific formulation of territorial spatial pattern optimization for water, energy, and agricultural resources in the TGRA and can more accurately reflect the status of the ecological environment and changes of WEF over time. Moreover, this paper also gives full play to the growth advantages of shipping and aquatic products, implements effective soil erosion prevention and control measures, and establishes water-saving mechanisms and other measures in terms of water resources. Subregional plans for industrial structure and strengthening of waste gas and wastewater treatment facilities regarding energy resources are developed. Implement the cultivated land protection system and promote the superiority of crop varieties and other measures in terms of food resources.

Cross-sensitivity analysis of land use transition and ecological service values in rare earth mining areas in southern China

Exploring the cross-sensitivity between land use transformation and ecological service values in rare earth mining areas is of great significance for the development of ecological protection and restoration in rare earth mining areas. To study the impact of land use changes on ecosystem service functions in rare earth mining areas, firstly, the land use change trends in the study area from 2009 to 2019 were analyzed using the land transfer matrix; then the distribution of ecosystem service values and the flow direction of ecosystem service values in the study area were measured based on the ecosystem service value equivalents; a spatial autocorrelation analysis was done on the ecosystem service values to explore their spatial distribution patterns; and finally, the cross-sensitivity coefficient was used to quantitatively assess the extent and direction of the impact of land use change on ecosystem service values. The results show that the land use types in the study area are mainly forest land and farmland, with woodland accounting for the highest proportion of the study area. The ESV changes in the study area are consistent with the trend of land use transformation, with the overall increase and decrease being comparable, and the decrease in ESV is mainly concentrated in the areas with a large increase in mining land and construction land; during the study period, the study area was significantly reduced with low-low cluster areas and the ecological environment was improved; from 2009 to 2014, the ecological sensitivity coefficient is more variable, and is more sensitive to the net conversion between water and desert, from 2014 to 2019, the ecological sensitivity coefficient is less variable, and the most sensitive is the net conversion between cultivated land and water. The study area should be reasonably developed for rare earth resources and the ecological environment around the mining area should be reasonably protected to build an ecological security pattern.

Boundary of ecosystem services: Guiding future development and application of the ecosystem service concepts

Ecosystem Services (ESs) are either material or non-material benefits humans receive from ecosystems. Definitions, classifications, and typologies of ESs can vary to address different research and policy purposes. However, a boundary that distinguishes ESs from other ecosystem-related benefits (e.g., industrial products that consume raw materials, fossil fuels that used to be a part of ecosystems) is needed to avoid the risk of using ESs as an all-encompassing metaphor that captures any benefit. The boundary also maintains a common ground for communication and comparison of ESs across studies. To guide future development and application of the ES concepts, we suggest five criteria. ESs are (1) primary contributions of ecosystems, (2) flows assessed during a period or per time unit (not stock existing at a time point), (3) renewable (having the potential to be reproduced with a conceivable timeframe relevant to human use), (4) affected by biotic parts of ecosystems to occur. ESs include both biotic and some abiotic flows (e.g., water provisioning) but exclude abiotic flows (e.g., wind and solar energy) whose occurrence is unaffected by ecosystem functions, processes, or characteristics; and (5) inclusive to the benefits humans actually and potentially receive from ecosystems. These criteria link ESs with conservation of life-supporting and culturally important ecosystems, recognize use, option, and non-use values of ESs, and highlight ESs' sustainability.

Priority areas and benefits of ecosystem restoration in Beijing

Ecological restoration can significantly improve ecosystem services and human well-being and provide a basis for regional coordinated development and ecological security. To guide restoration efforts, information on the potential benefits of restoration was required to efficiently target investments. Although the number of studies focusing on ecosystem restoration has increased in recent decades, priority areas that integrate ecological and economic benefits have yet to be identified. We developed and applied a prioritization approach to identify potential priority sites in Beijing. We used the historical environmental data on Beijing to identify areas of degradation and to assess the feasibility of restoration. Ecosystem service and quality degradation, low ecosystem quality, and soil erosion were integrated into one index to indicate the restoration importance. Potential restoration benefits were mapped using the monetary value of six ecosystem services. Based on the importance and benefits of restoration, three scenarios were developed to identify priority restoration areas. In Beijing, restoring 30% of the degraded area (1531 km2) in priority areas by 2050 could increase the annual ecological benefit by more than 5 billion yuan, or approximately 787 million USD, and could decrease the ecological degradation index by 50%. By integrating explicit spatial information on restoration importance and restoration benefits, this methodology provides a feasible way to identify restoration priority areas and assess restoration benefits.

A new pattern to quantitatively evaluate the value of ecosystem services in the large-scale open-pit coal mining area

Introduction

Open-pit coal mining could disrupt the ecosystem and lead to the loss of service values for the ecosystem through direct occupation or indirect impacts on adjacent ecosystems.

Methods

In this research, we combined a new accounting system, gross ecosystem product (GEP), with spatial–temporal analyses to quantify the ecological variation and explore its driving factors in Pingshuo, a large-scale open-pit coal mining area in China. GEP is an aggregate accounting system that can summarize the value of provisioning, regulating, and cultural ecosystem services (ES) in a single monetary metric. The spatial–temporal approaches used in our study were known as exploratory spatial data analyses and interpretable models in machine learning. Both spatial and non-spatial data, including remote sensing images, meteorological data, and official statistics, were applied in the research.

Results

The results indicated the following: (i) From 1990 to 2020, the annual average growth rates of GEP decreased from 30.78 to 9.1%. Furthermore, the classified results of GEP revealed that the regions with rich ES quality rapidly reduced from 51.90 to 32.18%. (ii) Spatial correlation of GEP was significant, and the degree of spatial clustering was relatively high in the mining areas. Moreover, the mining areas also continually presented concentrated high-density and hot spot areas of GEP changes. (iii) The spatial–temporal effects were notable in the relationship between GEP and three socioeconomic factors, i.e., the mining effects, human activity intensity, and gross domestic product (GDP). (iv) The win–win development for both the economy and ecological environment in Pingshuo could be realized by restricting the annual growth rate of mining areas to between 4.56 and 5.03%.

Discussion

The accounting results and spatial–temporal analyses of GEP will contribute to the future regional sustainable development and ecosystem management in Pingshuo.