ABSTRACT
While many decisions regarding sample design and data collection are context dependent, there are a number of general guidelines and principles that are common to all biodiversity studies. These guidelines emphasize the importance of giving careful attention to:
The clear definition of research objectives in order to identify the types of management practice and levels of impact that are the focus of evaluation, as well as the different types of indicators that need to be sampled and measured.
Questions of experimental design, including the choice of reference sites, the distribution of existing management activities and disturbance regimes, and the definition of independent samples. Questions about stratification versus random or uniform designs require a careful assessment of potentially confounding factors, and the need to generate information that is useful for management while also accounting for unknown patterns of environmental variability in space and time.
The choice of appropriate variables for measuring and explaining observed changes in biodiversity. Sampled variables need to provide a reliable and understandable description of biodiversity patterns while not being prohibitively expensive or time-consuming to collect.
The choice of sampling methods and appropriate level of replication both between and within samples. Limited resources mean that all biodiversity monitoring programmes face a tension between securing samples of sufficient quantity (to permit extrapolation) and quality (to ensure reliability of individual estimates).
Whether sufficient time, resources and expertise are available to ensure that a proposed monitoring design is feasible.
The long-term viability and relevance of the monitoring programme, including the importance of preserving data integrity through careful recording and storage, and the need to be adaptive in the face of changing priorities and opportunities.
