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.