Scale

Abstract

All topics in ecology and conservation play out in space and time at multiple scales. These scales describe the spatiotemporal dimensions of patterns or processes. By understanding and quantifying spatial scale, it can profoundly influence our understanding of ecological patterns and processes, and it can alter conservation decisions. Scale has two primary components, grain and extent, and it can be applied to describe ecological phenomena, ecological sampling, or data analysis. Spatial scale has been shown to be important for ecological and conservation problems because ecological processes can operate at different scales and patterns can be fundamentally different depending on the scale at which they are quantified. Two general approaches to the problem of scale include multiscale and multilevel modeling. Multiscale modeling quantifies environment conditions at multiple scales by altering either the grain or extent of the analysis, and then evaluates which of the considered scales best explains a pattern or process. In multilevel modeling, the focus is on interpreting effects at different levels in an organizational hierarchy. We illustrate the use of buffer-based and kernel-based multiscale modeling of species–environment relationships using an example of reptile distribution (i.e., the southeastern five-lined skink, Plestiodon inexpectatus) in the Southeastern USA. Our example shows how to optimally identify the scale at which species respond to the environment but also illustrates how the quantification of pattern is highly correlated across scales, a common issue in multiscale modeling. We end by discussing some further advances in understanding and quantifying scale.