生物物种资源监测原则与指标及抽样设计方法

生物物种资源监测是了解生物物种资源现状、开展生物物种资源保护与管理的基础工作和重要手段.阐述了生物物种资源监测的科学性原则、可操作性原则和持续性原则.提出了监测计划的制定程序；监测计划应充分考虑所具有的人力、资金和后勤保障等条件,并进行定期评估.分析了指示物种在物种资源监测中的作用与不足；认为应选择具有不同生态需求和生活史的生物类群作为监测对象.讨论了监测指标的选取方法；监测指标应可测量、有科学基础、易被公众接受、低成本和高效益；监测方法应具有科学性,能检测到相应的变化,应采用高效率、低成本的标准化监测方法.分析了现有监测计划在抽样设计方面存在的问题,探讨了空间变异性和可检测率对监测数据误差的影响及其处理方式,讨论了样本量确定和监测样地的大小、形状及位置设计.监测样地要有较好的代表性,能在有限的监测面积中较好地反映监测区域内群落种类组成与数量特征.最后,讨论了生物物种资源监测的尺度和标准化问题.

Principles, indicators and sampling methods for species monitoring

Species monitoring is fundamental to species conservation. The Chinese Government promulgated the Strategy and Action Plan for Biodiversity Conservation in China (2011-2030) in September 2010. One of the short-term targets of the strategy and action plan is to establish a preliminary monitoring system for China''s biodiversity by 2015. In the same year, the Convention on Biological Diversity adopted what is known as the 2020 targets or the Aichi Targets. It is necessary to enhance biodiversity monitoring to implement the strategy and action plan and to achieve the 2020 targets. Europe and North America have a long history of species monitoring. However, China has very limited skills in this area, with outdated techniques and often inadequate facilities. In this paper, we analyzed methods used to develop monitoring plans, select monitoring indicators, and design sampling, based on experience related to species monitoring in Europe and North America, so as to provide guidance for the design of species monitoring networks in China. Species monitoring usually involves four steps, such as developing monitoring plans, implementing field monitoring, analyzing and reporting monitoring data, and evaluating the monitoring plans. The development of monitoring plans should address four questions: (1) why monitor? (2) where should monitoring be done? (3) what should be monitored? and (4) how should monitoring be conducted? Objectives of species monitoring should be explicit, measureable, and practical. The following taxa should be considered in selecting indicator species: (1) threatened species; (2) species with social or economic value; (3) species important to the maintenance of ecosystem structure and processes; (4) species sensitive to management intervention; and (5) species sensitive to ecosystem or habitat change. Taxa with different ecological requirements and different life histories should be selected as indicator species. Monitoring indicators should be measurable, science-based, understandable by the public, with low monitoring cost and high benefits. Typical indicators include species richness, abundance, survival rate, community composition, habitat health, and human intervention. Monitoring methods should also be science-based and can detect relevant changes. Standardized monitoring methods with high efficiency and low cost should be employed. Random sampling should be used in species monitoring. Sampling units should be selected randomly from the target population, where appropriate, stratified sampling should be employed, so as to reflect the features of target regions and to reduce bias or errors as far as possible. Monitoring plans should address spatial variation and detectability. The main means to avoid errors are to estimate and correct detectability. The calculation of sample size should ensure that actual changes can be detected effectively under a given confidence level. Sampling sites should be representative, and should reflect, with limited monitoring areas, the species composition and quantitative features of communities in the monitoring region. The scope, shape and locations of sample sites should also be considered in the sampling design. Monitoring plans should fully address conditions such as human resources available, funding and support facilities, and should be regularly assessed. Results of and problems in species monitoring should be reported regularly to relevant government bodies, so as to link species monitoring closely with conservation policies and actions. All steps in species monitoring should address the issue of standardization. The key elements to enhancing data standardization are to: (1) select and establish sampling sites strictly according to relevant requirements; (2) use well qualified monitoring staff skillfully for operating monitoring protocols and collect data in line with the protocols; and (3) establish and implement data appraisal procedures, so as to completely and carefully evaluate monitoring data.