海平面上升对生态系统服务价值的影响及适应措施

海平面上升导致了海岸线后退、沿海侵蚀、风暴潮加强、生物栖息地改变、湿地变迁等,引起了近海域生态系统服务价值的变化。以美国Hillsborough County为研究区域,应用SLAMM模型,模拟了海平面从2010年—2100年上升1m的情景下各类用地面积的变化,利用效益转移法评价了生态系统服务价值的变化。结果表明:1旱地面积减少3037 hm~2,湿地面积增加3037hm~2,其中河口水域、滩涂、盐沼、定期洪水沼泽面积大幅度增加;季节性洪水沼泽、潮汐淡水沼泽、河流潮汐、沙滩面积大幅度减少,其它类型湿地受影响较小。2湿地总面积的增加反而导致了生态系统服务价值总量的降低,从2010年的61672万美元降低到2100年的61548万美元,这是由于净水湿地和沙滩大面积损失引起的;其中艺术娱乐、水调节、气候调节、文化精神价值将下降,水供应、栖息地保护、干扰调节和废物处理价值将上升。3防护、适应、后退3种措施分别降低、不影响、提升了生态系统服务价值,应根据其适用范围综合应用以制定应对海平面上升的适应性措施。

Impact of sea level rise on ecosystem services values and adaptation measures

Sea level rise, one of the most obvious and direct effects of climate change in coastal areas, has become an important and urgent problem. Rising sea level has brought about coastline retreat, coastal erosion, storm surge strengthening, pollutant release, habitat change, and wetlands migration. In addition, it has caused changes in the ecosystem service value of coastal areas. Five processes of coastal ecosystems that may be affected by sea level rise are inundation, erosion, overwash, saturation, and accretion. Wetlands migration is simulated by the Sea Level Affecting Marshes Model and benefit transfer method in Hillsborough County, US, where the sea level is assumed to rise 1 m from 2010 to 2100. According to the calculation results, ecosystem services values for every 10 years are evaluated using the benefit transfer method. The results showed that dry land areas will decrease by 3037 hm², while wetlands will increase by 3037 hm² with sea level rise. Areas of estuarine open water, beaches, salt marshes, and regularly flooded marshes will increase by 394.29%, 380.62%, 141.93%, and 121.41%, respectively. The areas of irregularly flooded marshes, tidal fresh marshes, tidal flats, estuarine beaches, and inland shores will decrease by 95.52%, 91.31%, 59.29%, 37.59%, and 21.44%, respectively. Mangroves, inland open waters, swamps, inland fresh marshes, and cypress swamps will be less affected, and will decrease by 6.67%, 4.05%, 2.35%, 0.90%, and 0.10%, respectively. Increasing the total wetland area contributes to reducing the total ecosystem service value due to the large loss of beaches and freshwater wetlands. The values of art, entertainment, water regulation, climate regulation, spirit and culture will decrease, while the values of water supply, habitat protection, disturbance regulation, and waste disposal will increase. Extensive efforts have been devoted to adaptation planning and impact analysis in the face of rising sea levels. Protection, accommodation, and retreat are the main adaptation measures that have been adopted by both state and local governments in the U.S. The analysis results showed that different measures have very different impacts on ecosystem services values. According to the comprehensive application of these measures, planners develop adaptive strategies to cope with rising sea levels. Due to global differences in sea level rise, local topography, seawater erosion degree, and the existing measures, it is difficult to judge whether the impact of sea level rise will have beneficial or detrimental effects on an ecosystem. The case study of Hillsborough County needs more discussion, such as the uncertainty of sea level rise and scenario simulation, the change and valuing of ecosystem service value per unit area for different types of wetlands, and quantitative analysis for impacts of adaptation measures on ecosystem services. In addition, the application of SLAMM in Chinese research should also be considered.