基于生态系统服务的生态风险评价研究进展

生态风险评价对科学管理与保护生态系统具有重要的意义,为弥补传统生态风险评价方法的不足和提高风险管理的效率,将生态系统服务引入生态风险评价中进行发展和完善,成为了当前生态风险评价研究的前沿和热点。系统分析了生态系统服务在生态风险评价中的应用,指出生态系统服务在问题形成阶段中可明确保护对象和属性,在风险分析阶段可联系生态系统结构过程作用,在风险表征阶段及后续阶段能可提供清晰明确的评价结果,加强风险交流和管理,能有效地改进生态系统传统生态风险评价。在实践上,基于生态系统服务的生态风险评价可从3个不同层面开展:一是针对外界压力对某类特定功能或者系统中某些服务功能的影响,构建基于某种特定服务的实体属性评价方法;二是针对外界压力作用下生态系统结构与过程变化下对功能影响,构建基于复杂生态系统作用的评价方法,实现对生态风险的模拟评价;三是评价社会生态系统下外界驱动对人类福祉的影响时,可将DPSIR(Drive-Pressure-State-Impact-Response)理论模型运用到生态风险管理中,也可基于景观生态系统服务与压力源的空间作用关系,实现社会生态系统风险评价与管理。作为生态风险表征手段,可基于生态系统服务损失与不利服务进行表征,也可选取热力学等指标作为评估量纲。从理论、评价方法、风险管理等方面对基于生态系统服务生态风险评价给予展望。

Advancesin ecosystem service-based ecological risk assessment

Ecological risk assessment (ERA) plays an important role in ecosystem management and conservation. Due to the complex relationship among multirisk sources, multiple receptors, and multiple endpoints, the conventional ERA method has shortcomings when determining the definite protected objects, closely related to the functions of an ecosystem, and when implementing an assessment into practice. Introduction of ecological services into ERA can effectively fix these deficiencies and thus improve the assessment method; this approach has become one of the hot areas in this field of cutting-edge scientific research. In the present study, we systematically analyzed the role of an ecological service in the processes of ERA. We showed that integration of the ecological-service theory into ERA enables this method to explicitly ascertain the protected objects and attributes at the question formation stage, focus on the structures and processes of an ecosystem at the risk assessment stage, provide clear results of the evaluation at the risk characterization stage, and to strengthen the risk communication and evaluation in subsequent phases. Therefore, an ecological service is an ideal assessment endpoint in ERA. In practice, ERA that is based on ecological services can be carried out on three scales. For a particular functional ecosystem or ecosystem''s protected function, the evaluation method can be established according to the entity and attributes of a particular service, and then the researcher can utilize the impact matrix method to analyze the relation between the ecological service and the corresponding pressure. Second, considering the characteristics of an ecosystem such as integrity or dynamics, the evaluation method can be established on the basis of the complex role of the ecosystem. Ecological models such as the ecological network can be used to analyze the effects on an ecological service in relation to changes in ecological structures and functions. Third, for a specified socioecosystem, the DPSIR (drive-pressure-state-impact-response) framework can be modified to analyze the influences of pressures on human well-being based on the following process: driving factors-pressure-status change (environmental ecological elements)-impact (ecological service)-response (risk assessment). From the standpoint of landscape pattern-process, analysis of the spatial relation between the change in a landscape service and a risk source is useful for implementing the assessment into practice and taking effective measures. Besides, analysis of the trade-off between diverse ecological services was also helpful for risk management. In this study, we also analyzed the characterization form and applied cases of an ecological service to ERA; these situations include the loss of an ecological service and disservice. The features and advantages of the thermodynamic index serving as an evaluation dimension are also discussed here. Finally, we provide some suggestions on future studies on ecological service-based ERA in terms of the theory, assessment method, and risk management. As for the theory, an integrated index as well as representative parameters for ecological processes are needed. Regarding the method, it is useful to build a state-of-the-art ecological-risk assessment model for simulation of the effects of an ecosystem service according to various driving scenarios based on theory research, considering the characteristics of the ecosystem. In terms of risk management, in relation to theoretical methods of ecological service management and landscape ecology services, it is imperative to enhance the ecological risk community and management by strengthening the link between the evaluation process and the socioecological management process, with integration of theories and methods of ecological-service management and landscape ecology services.