Introducing wetland offset markets under development-restoration conflicts: The role of public offset credit supply.

Wetland offset markets (WOMs) are increasingly applied worldwide as powerful tools for mitigating conflicts between wetland development and restoration. Reducing benefit uncertainty is key to promoting private restoration and introducing WOMs, which necessitates sufficient and stable price signals. Given that governments are important suppliers in WOMs, this article aims to explore the role of public offset credit (OC) supply in delivering and adjusting price signals during WOM formation and evolution. A general spatial agent-based wetland offset market model is built to simulate landowners' behavior, price dynamics, and WOM evolution under different public OC supply schemes. The results show that the spontaneous formation of WOMs is a time-consuming process. Price signals of public OCs reduce price fluctuations at the early stage of WOMs. This price stabilizing effect can cause a long-term reduction in benefit uncertainty perceived by landowners. Therefore, public OCs can facilitate WOM formation either through the supply side with high supply prices or through the demand side with low supply prices. During the entire WOM evolution process, due to landowners' readaptation, cheap public OCs can cause significant market fluctuations following the ceasing of cheap public supplies. The impacts of public OC on wetland development and restoration might change over time, and the suitability of public OC supplies under different long-term wetland management preferences was analyzed. These findings can further the understanding of the process of introducing a new market mechanism, such as WOMs, and the role of the government as a supplier. The research results provide insights for WOM practices, public restoration and OC supply scheme design, and wetland development-restoration conflict coordination.

Assessment on Changes of Ecosystem Carbon Storage in Reservoir Area due to Hydroproject.

Hydropower offers significant value for global carbon peak and carbon neutrality. However, the construction of hydropower stations leads to significant changes in land use and cover structure in reservoir areas, which affect ecosystem services including carbon balance. Furthermore, the development and operation of hydropower project require vast investment. However, the reservoir ecosystem's carbon storage and carbon emission reduction caused by hydropower could offer economic benefits when the official carbon market trading in China was launched in 2021. Therefore, it is necessary to assess comprehensively the changes in carbon storage and its value to the ecosystem in reservoir areas. The evaluation is of great importance for carbon loss reduction, land management, and hydropower development. This study provides a comprehensive and effective framework for evaluating changes in carbon storage and has its value to the reservoir ecosystem. It combines land utilization classification data obtained from remote sensing image interpretation and the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) carbon storage model. Based on the case study of the Xiluodu reservoir area, they were evaluated from two aspects: physical quantity and value quantity. The results show that the carbon storage in the Xiluodu reservoir area increased by 8,504.42 Mg from 2000 to 2018. The spatial distribution of the carbon storage shows a trend of high in the north and west, but low in the south and east. The construction of hydropower stations and the rise of reservoir water level covered a large amount of land, which led to the loss of carbon storage in reservoir areas. By implementing soil and water conservation and vegetation protection policies, parts of the cultivated land and grassland were converted into forestland, which was the main source for increasing the ecosystem's carbon storage. Moreover, carbon emission reduction was achieved by hydropower. In terms of the monetary value, the carbon storage value of the reservoir ecosystem increased to 19 million RMB during the construction period (2005-2015). The carbon storage value of the reservoir ecosystem increased to 611 million RMB during the operation period (2015-2018). The latter was greater than the maintenance cost of the hydropower station and exceeded the amortized cost of hydropower development, indicating the feasibility and economic benefits of hydropower development. These findings provide guidance for future hydropower development decisions in Jinsha River Basin and also others.

Application of the environmental Gini coefficient in allocating water governance responsibilities: a case study in Taihu Lake Basin, China.

The equitable allocation of water governance responsibilities is very important yet difficult to achieve, particularly for a basin which involves many stakeholders and policymakers. In this study, the environmental Gini coefficient model was applied to evaluate the inequality of water governance responsibility allocation, and an environmental Gini coefficient optimisation model was built to achieve an optimal adjustment. To illustrate the application of the environmental Gini coefficient, the heavily polluted transboundary Taihu Lake Basin in China, was chosen as a case study. The results show that the original environmental Gini coefficient of the chemical oxygen demand (COD) was greater than 0.2, indicating that the allocation of water governance responsibilities in Taihu Lake Basin was unequal. Of seven decision-making units, three were found to be inequality factors and were adjusted to reduce the water pollutant emissions and to increase the water governance inputs. After the adjustment, the environmental Gini coefficient of the COD was less than 0.2 and the reduction rate was 27.63%. The adjustment process provides clear guidance for policymakers to develop appropriate policies and improve the equality of water governance responsibility allocation.