Study On Risk Assessment For Alien Species In Xiamen

Bio-invasion is one of the most significant global environmental issues in 21^st century, and it becomes the second leading threat to biodiversity next to habitat losses, particularly to an island type ecosystem. Successful bio-invasion will cause serious ecosystem damage, biodiversity reduction and losses of the social economy and public health.China, with a vast territory, possesses of abundant ecosystem diversity, there are significant difference in the effects of alien species among different ecosystems. Nowadays, from the central to the local government, it is far form perfect in the special laws and regulations as well as the risk assessment research related to the management of alien species. Current regulations and risk assessment tools mostly aim at the whole national circumstance of bio-invasion. Although they can provide the guidance and framework, They do not offer the practical tools for the local management of alien species. And there are very few of case studies about the alien species risk assessment aiming at ecosystem protection on the local scale, such as local ecosystem or administrative area.Xiamen, as a gulf-typed eco-city in the southeast coast of China, is particularly vulnerable to bio-invasion for its typical island ecosystem and other attributes. Facing to the serious bio-invasion situation, effective risk assessment tool and relevant legislation for introduced alien species and their management are urgently needed by the local decision-makers. Based on the status quo of bio-invasion in Xiamen as well as the requirement of the local managers, this thesis will conduct systematically research on the risk assessment for the alien species. The main conclusions are as follows:(1) Based on the discussion and research of the the bio-invasion process, the connotation and definition of "alien invasive species" and other relevant glossaries have been systematically analyzed, classified and explained from the aspects of alien species and pest categories and their relationship. (2) Based on the investigation and analysis of the status quo of bio-invasion in Xiamen, a list of alien plants togethered with their distribution identified as major invaders (13 species) and emerging invaders (55 species) has been compiled.(3) Based on the analysis of the integrated bio-invasion process and the attributes of each stage of this process, a risk assessment framework for alien species has been proposed. Considering the characteristics of the ecosystem, status quo of alien plants invasion and the requirement of the local manager, a risk assessment indicator system for alien plants in Xiamen has also been established on the basis of the framework. The assessment system can meet the requirements of the policy-makers in preventing the introduction of high-risk species and the management of established alien species, since it has been designed to consist of two parts: "Introduced type risk assessment system" and "Existence type risk assessment system". 50 well-known species, which represent different degree of hazards and impacts in the local and adjacent areas, has been chosen as candidates for the validation of the proposed risk assessment system, and it works well, since the results of the assessment basically accord with the actual hazards caused by these plants. According to the result, the risk rank of the introduced alien plants in Xiamen has been determined.(4) Using the established "Introduced type risk assessment system", we assessed the introduced risk for two species of mangrove plants, Sonneratia apetala and Laguncularia racemosa, which were planned to be introduced for Coastal Zone Mangrove Ecosystem Restoration Project along east sea area of Xiamen in 2007. The results are as follows: Sonneratia apetala gained the risk values of 42(41), and Laguncularia racemosa as 40(36.5), they all been ranked as "Represents certain risk, gaining relevant information for further research or taking some measures for prevention and supervision is needed". This work can provide the valuable consultation and relevant control proposition for the introduced plants in the Mangrove Ecosystem Restoration Project in Xiamen.(5) After discussing the feasibility of applying environment impact assessment (EIA) as a tool in the risk assessment of introduced species, we proposed the procedures, contents and relevant requirements in EIA for alien species risk assessment.(6) On the basis of the research and analysis on the current situation of the relevant laws and regulations and bio-invasion management in China, recommendation and countermeasures for legislation and management on alien species in Xiamen has been proposed, which involves enacting a special law or regulation, strengthening the management constitution and establishing the concrete management systems. These propositions would provide useful consultation for the local bio-invasion management and dicision-making.