Predicting population and community dynamics: The type of aggregation matters

When investigating complex ecological dynamics at the population or community level, we necessarily need to abstract and aggregate ecological information. The way in which information is aggregated may be crucial for the outcome of the study. In this paper, we suggest that in addition to the traditional spatial, temporal and organizational levels, we need a more flexible framework linking ecological processes, study objects and types of aggregation. We develop such a framework and exemplify the most commonly used types of aggregation and their potential influence on identifiable drivers of community dynamics. We also illustrate strategies to narrow down the range of possible aggregation types for a particular study. With this approach, we hope (i) to clarify the function of aggregation types as related to traditional ecological levels and (ii) to raise the awareness of how important a deliberate way of aggregating ecological information is for a sound and reliable outcome of any empirical or theoretical ecological study.