Towards a taxonomy of spatial scale-dependence
12 September 2014Sandel, Brody
Spatial scale-dependence is a ubiquitous feature of ecological systems. This presents a challenge for ecologists who seek to discern general principles. A solution is to search for generalities in patterns of scale-dependence – that is, what kinds of things are scale-dependent, in what ways, and why? I argue that this is likely to be a productive way forward for ecology, but that progress in this direction is currently hindered by the conflation of a set of distinct concepts under the category of “scale-dependence.” Here, I propose a taxonomy of spatial scale-dependence that categorizes its major types in hopes of moving towards a more formal and unambiguous vocabulary. I argue that three major distinctions are necessary and sufficient for this goal: that between grain size and extent (the scale component), between data and models (the subject), and between true and perceived scale-dependence (the class). I illustrate the need for these distinctions with a set of examples demonstrating causes of different types of scale-dependence. I then describe how this taxonomy relates to an array of scale-related concepts from other fields. Finally, I discuss the generalization that biotic interactions are most important at small scales in light of this taxonomy.