生物多样性指示因子在我国森林景观应用中的有效性强度研究

Study on the Strength of Evidence of Biodiversity Indicators for Forest Landscape in China

发展可用于实际操作的生物多样性指示因子是落实以生物多样性为导向的森林景观规划与管理的关键。然而,很少有研究案例具体量化所选用的生物多样性指示因子与目标生物多样性之间是否存在相互联系。因此,指示因子与森林生物多样性的相互关系其及相互关联程度有必要进行严格地检验与评价。本文基于对大宗文献数据的分析,旨在为我国森林景观规划与管理提出一套具有科学依据的森林生物多样性指示因子名录。具体目的如下:(1)总结并建立指示因子与目标生物多样性之间的相互关系;(2)评估指示因子与目标生物多样性之间具有科学依据的相关性强度;(3)识别若干具有较强科学依据的指示因子,从而为森林资源政策性文件的制定、以生物多样性为导向的森林景观规划与管理提供理论基础。结果表明:(1)在被筛选出的50篇森林生物多样性研究的科技论文中,共识别出10个指示因子组别和54个指示因子个体,其中植被结构、时间与其他结构因子是使用最多的指示因子组别,林龄和郁闭度则是使用最频繁的指示因子个体;(2)有18篇论文研究没有实地检验指示因子和目标生物多样性之间的关系,其中13篇甚至没有提出明确的目标生物多样性;(3)在其余32篇论文中,共识别出89项指示因子与目标生物多样性的相关性,然而仅有3项具有重度相关性、7项具有中度相关性,并且均为结构指示因子在林段尺度下检验的;(4)重度相关性为,a.郁闭度与林下维管束植物多样性呈负相关,b.林下维管束植物物种组成随郁闭度变化而改变,c.垂直层级结构与维管束植物多样性呈正相关。研究结果显示,大部分用于森林生物多样性监测、规划与管理的指示因子都缺少有效性的科学依据,因此验证其有效性应为生物多样性保护的首要措施。最后,本文为生物多样性指示因子在我国森林景观规划与管理中的应用提出了相关建设性意见。

Developing practical biodiversity indicators is indispensable in biodiversity oriented forest landscape planning and management.However few studies have quantified forest biodiversity targets related directly to specific biodiversity indicators.Therefore,there is a need to evaluate,critically assess the strength of evidence for the relationship between indicators and the indicated aspects of biodiversity(i.e.target biodiversity)in forest ecosystems.Biodiversity indicators proposed for forest ecosystems in China were reviewed with the overarching aim of providing advice on strategic selection and combination of indictors.The objectives are:(1)Establish interrelationships between indicators and their target biodiversity;(2)Assess the strength of scientific evidence between individual indicators and their target biodiversity;and(3)Identify a set of indicators with confirmed validity for further scientific testing and inclusion in long-term reporting and decision-making regarding forest biodiversity.The results showed:(1)Ten indicator groups and 54 individual indicators were identified with application mainly on stand scale in 50 eligible scientific papers.Vegetation structure and temporal and other structural indicators were the most applied indicator groups,and age of canopy trees as well as tree canopy cover were the most frequently used individual indicators.(2)In 18 of the 50 studies no statistical correlations between indicator(s)and target biodiversity were performed and 13(out of the 18)did not even present a clear target biodiversity.(3)In the remaining 32 studies,89 correlations between indicator and target biodiversity were identified.However,only3 correlations were assessed as being supported by strong evidence,and 7 were assessed as being supported by moderate evidence,all of which were tested on stand scale.(4)About the strong evidences,(a)A negative correlation was found between tree canopy cover and understory vascular plant species richness;(b)The species composition of understory vascular plant changed with the tree canopy cover;(c)A positive correlation was found between vertical stratification and vascular plant species richness.These results imply that the validity of most indicators on which monitoring and conservation planning are based are weakly scientifically supported and that further validation of current biodiversity indicators for forest ecosystems is needed.Accordingly,constructive suggestions were proposed concerning biodiversity oriented forest landscape planning and management in China.