Spatiotemporal variability and extrapolation from ecological experiments

Abstract In current philosophy of science, extrapolation is seen as an inference from a study to a distinct target system of interest. The reliability of such an inference is generally thought to depend on the extent to which study and target are similar in relevant respects, which is especially problematic when they are heterogeneous. This paper argues that this understanding is underdeveloped when applied to extrapolation in ecology. Extrapolation in ecology is not always well characterized as an inference from a model to a distinct target but often includes inferences from small-scale experimental systems to large-scale processes in nature, i.e., inferences across spatiotemporal scales. For this reason, I introduce a distinction between compositional and spatiotemporal variability. Whereas the former describes differences in entities and causal factors between model and target, the latter refers to the variability of a system over space and time. The central claim of this paper is that our understanding of heterogeneity needs to be expanded to explicitly include spatiotemporal variability and its effects on extrapolation across spatiotemporal scales.