Scope and its role in advancing a science of scaling in landscape ecology

Context: The scope of a measurement is the ratio of the range (or extent) to the resolution. Scope can also be defined as the number of steps in a measurement instrument given the step size or the distance between two points on a space-time diagram. Scope differs from scale in that it is dimensionless and thus provides a means for comparability across studies. Objectives: This perspective argues that advancing a science of scaling in landscape ecology can benefit from acknowledging and embracing the concept of scope to facilitate replications and provide linkages to scaling laws. Methods: Scope is defined and linked to existing focii on scale in landscape ecology. A simple case study demonstrates how landscape metrics computed for several extent-to-grain ratios are more similar according to scope than either grain or extent. Results: Metric distributions naturally group according to scope, with same/similar scopes displaying more similar means and distributions. Distribution shapes also show similarities according to scope, supporting the use of scope for comparisons and replications. Conclusions: Recommendations for moving forward include setting the scope of a study based on the phenomenon under investigation, reporting grain and extent to permit scope calculations, and undertaking comparisons and replications based on scope.