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Abstract: Hydropower is an important service provided by ecosystems. We surveyed all the hydropower plants in the Zagunao River Basin, Southwest China. Then, we assessed the hydropower service by using the InVEST (The Integrated Value and Tradeoff of Ecosystem Service Tools) model. Finally, we discussed the impact on ecological compensation. The results showed that: 1) hydropower service value of ecosystems in the Zagunao River Basin is 216.29Euro/hm2 on the average, of which the high-value area with more than 475.65Euro/hm2 is about 750.37km2, accounting for 16.12% of the whole watershed, but it provides 53.47% of the whole watershed service value; 2) ecosystem is an ecological reservoir with a great regulation capacity. Dams cannot completely replace the reservoir water conservation function of ecosystems, and has high economic and environmental costs that must be paid as well. Compensation for water conservation services should become an important basis for ecological compensation of hydropower development. 3) In the current PES cases, the standard of compensation is generally low. Cascade development makes the value of upstream ecosystem services become more prominent, reflecting the differential rent value, and the value of ecosystem services should be based on the distribution of differentiated ecological compensation. [Copyright &y& Elsevier]

Abstract: Effective flood management measures incorporate the flood mitigation functions of natural ecosystems, but the exact functions and effects of forests, grasslands and other ecosystems in mitigating floods are not clearly understood. In this paper, a flood mitigation assessment model was established based on the Soil Conservation Service (SCS) method, and the function and potential capacity of ecosystems for mitigating flooding in the Upper Yangtze River Basin (UYRB) were assessed. The monetary value of flood mitigation service was calculated by formulating an exponential function with respect to the amount of storm and flood damage. The results showed that ecosystems in the UYRB reduced flooding by a total of 42.8 billion cubic meters. Statistical equations developed for the amount of storm and flood damage gave an average of 6.479 billion RMB Yuan as the value of ecosystem flood mitigation in the UYRB. Despite their small cost, ecosystems have the potential to reduce flood damage by more than half, an indication of the important role of ecological systems in flood management. This approach can be used to identify high-value areas for ecological protection, and also to provide the governments at various levels with important information for decision-making related to integrated flood management. [Copyright &y& Elsevier]

Abstract: On 12 May 2008, a magnitude 8.0 earthquake struck China''s south-western region (the Wenchuan earthquake). It not only caused large numbers of human casualties and property loss, but also damaged the ecological environment profoundly and led to the loss of ecosystem services, threatening ecological safety. Evaluation of the loss of the ecosystem services was vital for post-disaster reconstruction. A GIS-based ecosystem services evaluation model, InVEST (Integrated Valuation of Ecosystem Services and Tradeoffs), was used to make a quantitative assessment of the effects of the earthquake on three critical ecosystem services – water retention, soil conservation and carbon storage – and to analysis the spatial variability of ecosystem services. The results showed that although the area destroyed by the earthquake was small, the loss of ecosystem services was nevertheless considerable. The soil conservation service suffered the most serious losses, followed by the carbon storage service and water-related ecosystem services. The disturbance to ecosystem services lessened gradually outwards from the epicenter. Earthquake intensity zones X and XI accounted for more than 80% of the ecosystem service losses over the whole area affected by the earthquake. Zones VIII and IX suffered some losses, but were less severe than in zones X and XI. Zones VI and VII experienced only a minor loss of ecosystem services. At higher ground elevations, the damage to water conservation, soil conservation and carbon storage functions increased at first, then decreased; however, damage increased steadily with steepening slopes. [Copyright &y& Elsevier]

Abstract: Non-point source pollution is one of the crucial causes leading to degradation of rivers and lake water quality; therefore, it has been studied in depth worldwide. However, few studies exploring the effect of terrestrial ecosystem nutrient retention function on water quality have been conducted to date. Natural ecosystems such as forests and grassland can hold runoff and sediment, thereby reducing the nutrients entering nearby aquatic systems, which is very important to improving water quality. Based on the landscape source-sink theory, this study assessed the nutrient retention function of ecosystems. The results showed that terrestrial ecosystems retained 78% of the Total Nitrogen (TN) within the system, thereby significantly reducing the TN entering the water. The nutrient retention function of different ecosystems varied significantly. Forests had the greatest potential capacity to maintain TN, but the actual retained TN was only about 10% of that applied to cropland. Because of irrational land use patterns, the potential forest intercepting nutrient function was not fully utilized. Specifically, nutrient retention function varied with altitude and slope. When the altitude was in the range of 1000 m or between 4000 m and 4500 m, the highest function could be attained, resulting to increases or decreases between regions. The nutrient retention function decreased as slope increased. The critical source area (CSA) was primarily distributed along the river bank. However, the critical sink area which made a high contribution to nutrient reduction did not appear that similar distribution like CSA. The critical sink area scatted in the whole basin mainly and only overlapped with the critical source areas in some place. [Copyright &y& Elsevier]