Evaluation of Water Provision Ecosystem Services Associated with Land Use/Cover and Climate Variability in the Winike Watershed, Omo Gibe Basin of Ethiopia

Long-Term Effects of Ecological Restoration Projects on Ecosystem Services and Their Spatial Interactions: A Case Study of Hainan Tropical Forest Park in China

Ecological restoration projects aim to comprehensively intervene in damaged or deteriorating ecosystems, restore them, improve the provision of ecosystem services, and achieve harmonious coexistence between humans and nature. Implementing ecological restoration projects leads to continuous changes in land use/land cover. Studying the long-term changes in land use/land cover and their impacts on ecosystem services, as well as the trade-off and synergy between these services, helps evaluate the long-term effectiveness of ecological restoration projects in restoring ecosystems. Therefore, this study analyzes the land use/land cover, and ecosystem services of the Hainan Tropical Forest Park in China to address this. Since 2000, the area has undergone multiple ecological restoration projects, divided roughly into two stages: 2003-2013 and 2013-2021. The InVEST model is used to quantify three essential ecosystem services in mountainous regions (water yield, carbon storage, and soil conservation), and redundancy analysis identifies the primary driving factors influencing their changes. We conducted spatial autocorrelation analysis to examine the interplay among ecosystem services under long-term land use/land cover change. The results indicate a decrease in the total supply of water yield (-5.14%) and carbon storage (-3.21%) in the first phase. However, the second phase shows an improvement in ecosystem services, with an increase in the total supply of water yield (11.45%), carbon storage (27.58%), and soil conservation (21.95%). The redundancy analysis results reveal that land use/land cover are the primary driving factors influencing the changes in ecosystem services. Furthermore, there is a shift in the trade-off and synergy between ecosystem services at different stages, with significant differences in spatial distribution. The findings of this study provide more spatially targeted suggestions for the restoration and management of tropical montane rainforests in the future.

The impacts of climate change on hydrological processes of Gilgel Gibe catchment, southwest Ethiopia

Climate change is a significant driver of water resource availability, affecting the magnitude of surface runoff, aquifer recharge, and river flows. This study investigated the impact of climate change on hydrological processes within the Gilgel Gibe catchment and aimed to determine the level of exposure of water resources to these changes, which is essential for future adaptability planning. To achieve this objective, an ensemble mean of six regional climate models (RCMs) from the coordinated regional climate downscaling experiment (CORDEX)-Africa was used to simulate future climatic scenarios. The RCMs outputs were then bias corrected using distribution mapping to match observed precipitation and temperature. The Soil and Water Assessment Tool (SWAT) model was used to assess the hydrological impacts of climate change on the catchment. The results indicated that the ensemble mean of the six RCMs projects a decline in precipitation and an increase in temperature under both the RCP4.5 and RCP8.5 representative concentration pathways. Moreover, the increases in both maximum and minimum temperatures are higher for higher emission scenarios, indicating that RCP8.5 is warmer than RCP4.5. The projected climate change shows a decrease in surface runoff, groundwater, and water yield, resulting in an overall decline of annual flow. This decline is mainly due to the reduction in seasonal flows driven by climate change scenarios. The changes in precipitation range from -11.2% to -14.3% under RCP4.5 and from -9.2% to -10.0% under RCP8.5, while the changes in temperature range from 1.7°C to 2.5°C under RCP4.5 and from 1.8°C to 3.6°C under RCP8.5. These changes could lead to reduced water availability for crop production, which could be a chronic issue for subsistence agriculture. Additionally, the reduction of surface water and groundwater could further exacerbate water stress in the downstream areas, affecting the availability of water resources in the catchment. Furthermore, the increasing demands for water, driven by population growth and socioeconomic progress, along with the variability in temperature and evaporation demands, will amplify prolonged water scarcity. Therefore, robust climate-resilient water management policies are indispensable to manage these risks. In conclusion, this study highlights the importance of considering the impact of climate change on hydrological processes and the need for proactive adaptation measures to mitigate the impacts of climate change on water resources.

Integrating Ecosystem Health and Services for Assessing Ecological Risk and its Response to Typical Land-Use Patterns in the Eco-fragile Region, North China

Changes in land-use patterns may increase the ecological risks faced by Eco-Fragile regions. It is vital for regional ecological restoration and management of Eco-Fragile regions to reasonably assess ecological risk and study its response to typical land-use patterns. Existing study on regional ecological risk largely ignored the internal representation of ecosystem health and ecosystem services to ecological risk, and also ignored the internal relationship between ecological risk and land use patterns. This study developed a regional ecological assessment model by describing the relationship between ecosystem health, ecosystem services and ecological risks. Among them, the ecosystem health assessment used the Net Primary Productivity, landscape index and ecosystem elasticity coefficient based on different land use patterns to build Vigor-Organization-Resilience (VOR) model, and the improved equivalent factor method was used to calculate the ecosystem service value. Taking the Fen River Basin (FRB), a typical Eco-Fragile region of the Loess Plateau, as a study region, spatial auto-correlation analysis was used to reveal the temporal and spatial changes and spatial clustering characteristics of regional ecological risk, and regression analysis was used to study the relationship between typical land use patterns and ecological risks, which was included in the consideration of ecological and environmental risk management strategies. The results show that the regions with high ecological risk are mainly distributed in the middle and southwest of the FRB; the regions with low ecological risk are mainly distributed in the north, east and west of the FRB. Both high-risk and low-risk areas show significant spatial clustering effects. The change of ecological risk in FRB is related to the land use patterns. The ecological risk is negatively related to the expansion of construction land and cultivated land at the county and patch scales. On this basis, the environmental management strategies at different scales are discussed. This study can helpful deepen the understanding of the impact of land use patterns on ecological risk, and can also provide important reference for regional ecological risk management and land use policies.

Spatio-Temporal Characteristics of Trade-Offs and Synergies in Ecosystem Services at Watershed and Landscape Scales: A Case Analysis of the Yellow River Basin (Henan Section)

The changes and interrelationships of ecosystem services at different global and regional scales have been actively investigated. Clarifying the trade-offs and synergies between ecosystem services from a multi-scale scientific perspective is vital to improve the coordinated and sustainable development of the watershed and ecological protection. As an important ecological barrier region of the Yellow River Basin, the Henan section provides a variety of important ecosystem services. This study analyzes the characteristics of land use changes in the Yellow River Basin (Henan section) from 1990 to 2020. Based on the InVEST model, four ecosystem services-water production, soil conservation, carbon storage and food supply have been evaluated. The Spearman correlation coefficient was used to further reveal the spatial and temporal characteristics of the trade-offs and synergies at different levels of each service. The results showed that: (1) From 1990 to 2020, the basin was dominated by farmland conservation. The construction land area mainly exhibited an inflow behavior, while other land use types were mainly related to outflow. (2) From 1990 to 2020, the water yield, soil conservation and carbon storage first increased and then decreased, while food supply gradually increased. The spatial distribution of these ecosystem services was lower in the southwest and slightly higher in the northeast and farmland had the highest capacity of water production and food supply, while woodland had the highest capacity for soil conservation and carbon storage. (3) The Spearman rank correlation coefficient indicated that the trade-offs for the ecosystem services in the Yellow River Basin (Henan section) dominated before 2000, and the synergies gradually strengthened after 2000. (4) There were clear spatial heterogeneities in the ecosystem services of the basin; for instance, the functions in the middle and lower reaches of the Yellow River Basin (Henan section) were mainly trade-offs, while the higher elevations in the middle reaches exhibited synergistic relationships. This study aims to clarify the trade-offs and synergies between ecosystem services at the different levels. Based on our findings, countermeasures and suggestions for ecological protection and management are proposed to promote the coordinated development of social economy and ecological protection.

Understanding the Mechanism of Urbanization Affect Agricultural Water Efficiency: Evidence from China

Concerns regarding food security and sustainable development have been highlighted as a result of water scarcity and growing urbanization. It is imperative to look into their relationship. This study examines the impact of urbanization on agricultural water efficiency (AWE) in China utilizing China province-level panel data from 2002 to 2019. The findings indicate that urbanization has a U-shaped relationship with AWE, meaning that urbanization first had a detrimental effect on AWE before reversing course. These findings are robust to the inclusion of three measures of urbanization and the estimation of the instrumental variable method. Structural equation modeling of the underlying mechanisms demonstrates that, at higher levels of urbanization, planting structure and irrigation facilities partially mediate the urbanization-AWE relationship; the mediate effects account for between 27.3% and 100% of total effects, depending on the urbanization measurement used. China should continue investing in rural irrigation infrastructure as it urbanizes, as this would improve water efficiency.