城市红树林生态系统健康评价与管理对策——以粤港澳大湾区为例

为解明粤港澳大湾区城市红树林生态系统健康状况,基于PSR (压力-状态-响应)模型和层次分析法,构建了城市红树林生态系统健康评价指标体系,对大湾区的香港米埔、深圳福田、广州南沙和珠海淇澳岛4个典型城市红树林进行生态系统健康评价,识别健康问题并提出管理对策.结果表明:红树林生态系统健康指数(EHI)为淇澳岛(3.05,健康)>米埔(3.03,健康)>南沙(2.54,亚健康)>福田(2.13,亚健康).就压力指标而言,米埔和福田红树林的自然压力源为病虫害和生物入侵,人为压力源为人口、经济相关指标及城镇生活污水排放,福田还受到工业废水排放的压力.就状态指标而言,红树林受海水营养盐污染严重,南沙和淇澳岛红树林存在严重的有机污染和重金属污染;红树植物多样性(除南沙红树林外)和大型底栖动物生物多样性偏低,但鸟类生物多样性处于较高水平.就响应指标而言,福田和南沙红树林由于面积小而生态服务功能偏低,南沙红树林的管理水平不足.粤港澳大湾区城市红树林存在的主要健康问题包括生态失衡导致的病虫害与生物入侵、受纳外源污染导致的环境污染、栖息地破坏导致的生物多样性下降的共性问题及自身特征与管护水平差异导致的其它个性问题.针对上述健康问题,建议:以缓解生态失衡为目标高效监测并推广基于自然法则的生态恢复,以源头控制为根本整体改善环境质量,以保护生物多样性为重点提高红树林生态系统稳定性,因地制宜充分发挥城市红树林经济-社会-生态效益.

Ecosystem health assessment and management strategies of urban mangrove:A case study of Guangdong-Hong Kong-Macao Greater Bay Area

To clarify the ecosystem health status of urban mangroves in Guangdong-Hong Kong-Macao Greater Bay Area (GBA), an indicator system for ecosystem health assessment of urban mangroves was developed based on PSR (Press-State-Response) model and analytic hierarchy process in this study. The indicator system was conducted on four typical urban mangroves in GBA: Mai Po in Hong Kong, Futian in Shenzhen, Nansha in Guangzhou, and Qi’ao island in Zhuhai. The health problems were identified and management strategies were put forward. The results showed that: The ecosystem health index (EHI) of mangroves were Qi’ao island (3.05, health)>Mai Po (3.03, health)>Nansha (2.54, sub-health)>Futian (2.13, sub-health). As for the press indicators, the natural pressure sources for mangroves in Mai Po and Futian were pests harm and biological invasion, while the artificial pressure came from the increasing population, the rapidly developed economy, and municipal wastewater discharge. In addition, the mangroves in Futian were suffering from the discharge of industrial waste. In terms of the state indicators, four urban mangroves were all suffering from seawater eutrophication. Organic and heavy metals seriously polluted the mangroves in Nansha and Qi'ao Island. The biodiversity of mangrove plants (except for Nansha) and macrobenthos was low, but birds' biodiversity was relatively high. For the response indicators, the mangroves in Futian and Nansha hold low ecological service functions due to their small areas, and the management level of mangroves in Nansha was insufficient. The leading health problems of urban mangroves in GBA include two aspects: firstly, common issues, including pests harm and biological invasion caused by ecological imbalance, environmental pollution caused by external pollution, decrease in biodiversity caused by habitat destruction. Secondly, personality issues, including the differences in the characteristics and management levels of mangroves. Considering the health problems mentioned above, suggestions are proposed: effectively monitor and promote ecological restoration based on natural laws to alleviate ecological imbalance, take source control as the foundation and improve environmental quality as a whole, focus on the protection of biodiversity and improve the stability of mangrove ecosystem, in accordance with local conditions and give full play to the economic, social and ecological benefits of urban mangrove.