全球气候变化下南海诸岛保护优先区识别分析

Identifying priority conservation areas for South China Sea Islands under the global climate change

全球变化下,珊瑚礁保护区是保护生物多样性、增强珊瑚礁对气候变暖抵抗力的有效方式,而维持珊瑚礁弹性是其核心内容。针对珊瑚礁最具有威胁性的热压力因子,基于南海1982-2009年卫星观测海表面温度(SST)数据和CMIP5加拿大地球系统模式CanESM2模型预估的2006-2100年南海SST数据构建热压力强度模型,从维持珊瑚礁弹性的角度识别IPCC RCP 4.5和RCP 8.5情景下南海诸岛保护优先区。结果表明:RCP 4.5和RCP 8.5情景下13%左右的南海诸岛珊瑚礁识别为保护优先区。根据热压力强度与珊瑚抵抗力及避难所关系,西沙群岛七连屿和晋卿岛近年观测与未来预估的热压力强度均比较低,在保障其服务功能的基础上建议实施完全保护;东沙群岛东沙环礁和中沙环礁排洪滩近年观测急性热压力强度较高但未来预估热压力强度较低,建议实施50%禁止利用保护;中沙群岛黄岩岛近年观测和未来预估的急性热压力强度均比较低,建议实施50%多用途保护。南沙群岛有14%左右的珊瑚礁识别为保护优先区,根据其热压力强度可实施30%~100%禁止利用保护或30%~50%多用途保护。RCP 4.5和RCP 8.5情景下的南海诸岛保护优先区及保护对策,可为维持珊瑚礁生态弹性及应对全球气候变化提供重要的参考价值。

Under the global change,coral reef reserves pave an effective way to protect biodiversity and enhance coral reef resistance to climate warming.Moreover,maintaining coral reef resilience is the core of coral reef reserves.Based on thermal stress,which is the most serious factor of coral reefs,this paper builds a thermal stress intensity model adopting the satellite sea surface temperature data(SST)of the South China Sea from 1982 to 2009 and the predicted SST data of the Second Generation Canadian Earth System Model(CanESM2)in CMIP5 from 2006 to 2100.Coral reefs that have priority to be protected in RCP4.5 and RCP8.5 scenarios are distinguished from the view of maintaining their resilience.The results show that about 13%of the coral reefs in the South China Sea Islands are identified as priority areas for protection.Based on the relationship between thermal stress intensity and coral resistance as well as refugia,thermal stress intensities of Qilianyu and Jinqing Island in the Xisha Islands both in recent years and in the future are relatively low.Thus,they are recommended to implement complete protection policies after acting their service function.Dongsha Atoll of Dongsha Islands and Paihong Reef of Zhongsha Atoll have experienced serious acute thermal stress in recent years,for which 50%prohibition of protection are recommended.The acute thermal stress intensities both in recent observations and in future projections of Huangyan Island of Zhongsha Islands are relatively low.Fifty percent multipurpose protection is recommended for Huangyan Island.About 14%of the coral reefs in the Nansha Islands are priority areas for protection,and 30%-100%for prohibition of protection or30%-50%for multi-purpose protection can be implemented.The extracted reefs and the protection measures for the South China Sea Islands under the RCP4.5 and RCP8.5 scenarios can provide important reference value for maintaining the ecological resilience of coral reefs to cope with global climate change.