近岸多源环境因素影响下珊瑚群落的生态脆弱性评价研究

Ecological Vulnerability Assessment of Coral Community under the Impact of Multiple Environmental Factors

珊瑚礁作为典型脆弱生态系统,易受到环境条件和人类活动等多源因素的影响。以中国造礁石珊瑚集中分布的最北界——福建东山为研究区域,在空间分析技术的支持下将自然-社会-经济因素融入珊瑚礁脆弱性评价指标体系,基于ESA(Exposure-Sensitivity-Adaptive capacity)模型建立近岸多源环境因素影响下珊瑚群落的生态脆弱性评价方法,评估珊瑚群落生态脆弱性的等级和空间分布,探索环境因素与珊瑚群落状态之间的定量关系,为珊瑚群落生态保护和管理提供科学依据。结果表明,东山研究区珊瑚群落的生态敏感性整体评价值偏高,大多数站位评价值大于0.6,东山湾口、东门屿和澳角周边的珊瑚群落生态敏感性最高。综合而言,生态脆弱性较高的站位基本位于东山湾口、东门屿一带,站位的生态脆弱性综合评价结果均大于0.8,属于中度和高度脆弱站位。生态脆弱性较低的站位位于马銮湾-金銮湾内,站位生态脆弱性综合评价结果均小于0.3,表明该区域珊瑚群落状态较好。相关性分析和冗余分析结果显示,影响当地珊瑚群落状态的主要驱动因子是活性磷酸盐浓度、浊度和距海水养殖区距离。根据评价结果,保护区管控、海水养殖区划调整和水质改善等措施可能对降低东山珊瑚群落的生态脆弱性具有显著的积极意义,可从以上方面开展基于生态系统的管理,有利于消减外源驱动因子,维持珊瑚群落的生态系统功能与服务。

Coral reef,as a typical vulnerable ecosystem,is easily affected by multiple factors such as environmental conditions and human activities.The northernmost boundary of scleractinian coral in Dongshan,China,was taken as the study area.With the support of spatial analysis technology,the natural,social and economic factors were integrated into the index system of coral reef vulnerability assessment,and an assessment method of coral ecological vulnerability under the impact of nearshore multiple environmental factors was established based on ESA(Exposure-Sensitivity-Adaptive capacity)model.It can assess the level and spatial distribution of coral ecological vulnerability,explore the quantitative relationship between environmental factors and coral status,and provide a scientific basis for the ecological protection and management of coral.The results showed the overall assessment values of coral sensitivity in Dongshan study area were relatively high.Most stations’sensitivity assessment values were more than 0.6 and the sites around the mouth of Dongshan Bay,Dongmenyu and Aojiao had the higher ecological sensitivity value.Generally,the sites with high ecological vulnerability values which were more than 0.8 were located in the mouth of Dongshan Bay and Dongmenyu,belonging to moderate and high ecological vulnerability sites.While the sites with low vulnerability value which were less than 0.3 were located inside Maluan Bay-Jinluan Bay,indicating that the status of coral in this area was healthy.The correlation analysis and redundancy analysis indicated that the main pressure factors affecting the status of local coral community were active phosphate concentration,turbidity and the distance from mariculture.The study found that the management and control of protected areas,the adjustment of mariculture zones and the improvement of water quality may have a remarkable positive significance in reducing the ecological vulnerability of coral community in Dongshan.The ecosystem-based management can be carried out from the above aspects,which is conducive to reducing the impact of external driving factors and maintaining the functions and services of the coral ecosystem.