To successfully tackle the complexity of human-modified forest ecosystems biodiversity monitoring programmes need to make explicit the logic and assumptions that lie behind design choices and stated associations among individual system components.

Conceptual frameworks and models are powerful tools that can help in addressing these challenges. The process of developing conceptual models is as important as the product itself as it forces us to think about how systems work.

Conceptual frameworks are a means of categorizing variables and indicators and identifying which are most appropriate for assessment, while conceptual models are a method for articulating causal relationships and dynamics of the study system.

Well-conceived conceptual models can facilitate the development of biodiversity monitoring programmes in at least five inter-related ways by helping to: (i) contextualize the relative importance of evaluating different management impacts on biodiversity; (ii) make explicit our assumptions about the nature of human impacts on biodiversity; (iii) develop a basis for constructing research hypotheses; (iv) design robust sampling strategies for monitoring; and (v) provide a valuable aid to communicating biodiversity monitoring and research.

A validation monitoring programme needs to consider the factors that mediate the biodiversity consequences of a particular human impact or management intervention. An important function of a conceptual model is to help clarify these mediating factors, including the importance of interaction and synergistic effects as well as time-lags, thresholds, landscape context and stochastic dynamics in interpreting observed biodiversity patterns.

Conceptual models that encompass not only ecological factors but also the social processes that relate to the structure and function of forest management can be a highly effective way of integrating the monitoring process with the wider management system