战略环境影响评价中生物多样性影响评价特点

ATTRIBUTES OF BIODIVERSITY IMPACT ASSESSMENT IN STRATEGIC ENVIRONMENTAL ASSESSMENT

随着战略环境影响评价(Strategic Environmental Assessment,简称SEA)的发展,SEA被越来越广泛地用于生物多样性影响评价。由于受人类对生物多样性的研究和认识水平的限制,目前在国内外还没有成熟的方法用于生物多样性的影响评价,以致于生物多样性的影响评价内容不够具体和全面。从生物多样性的景观、生态系统、物种和基因4个层次分析了生物多样性影响评价在SEA中应用的限制因素。在此基础上,提出景观层次影响评价可以通过寻求易于测度的关键景观要素进行评价,宏观把握景观变化给生物多样性带来的影响趋势;生态系统层次影响评价应充分考虑各种替代方案的比较,避免敏感目标的生物多样性重大损失;物种层次的影响评价选择重要的目标物种作为主要评价依据;受研究水平限制,基因层次的影响评价还不具有普遍意义。

Strategic environmental assessment （SEA） involves predicting, evaluating and mitigating the environmental impacts of plans and programs, thereby integrating environmental considerations into strategic decision-making. As an environmental appraisal tool,SEA has been more and more widely applied in biodiversity conservation. Current approaches and methodologies of biodiversity impact assessment （BIA） were ineffective, and the assessment results were rather unspecific and incomplete within SEA. In this paper, the limitations of BIA were reviewed and analyzed with specific focuses on four biodiversity levels （landscape, ecosystem, species and gene）, and some evaluating methods were suggested,which was expected to provide the references on the plans and programs, decision-makers and organizations across a wide range of sectors. For the indices of landscape change measurement were hardly linked with ecological processes on site, it was difficult to predict the biodiversity consequences of landscape changes resulting from developing programs. The key region which was easily reflecting ecological processes （such as biocorridor, protected area, ecotone,＂source＂ and ＂sink＂ landscape area） should been focused on landscape-level impact evaluation. Ecosystem degradation could not be weighed by real value,so the impacts of damaged ecosystem could not be foreseen in accuracy. The assessment of ecosystem-level impact should provide adequate options to avoid the loss of sensitive and important objectives. In practice, it was impossible to obtain the detailed information in a targeted area for the purpose of BIA, so the species-level impact assessment should be addressed through the studies on the key objectives like protected species, endemic species, economic important species,other genetic resources species,etc. For the phenotype of species could not express the entire genetic traits,it was difficult to measure the impacts on genetic diversity without the experimental data. Currently, the application of gene-level impact assessment was still constrained due to the information gap of gene diversity within populations.