Habitat configuration influences mammal populations at a wider spatial extent than habitat composition: a meta-analysis of forest mammal datasets

Abstract

Abstract Context The spatial extent at which landscape variables most strongly influences wildlife populations (i.e., scale of effect) is of key importance to ecology and conservation. Many factors can influence scales of effect, but these relationships are poorly understood. In particular, the way scales of effect vary with different landscape metrics has not been extensively tested. Objectives Our study examined whether metrics of landscape configuration have wider or narrower scales of effect than habitat composition. We also examined how a variety of factors (i.e., species traits and landscape context) influence the magnitude of these differences in scales of effect between metrics. Methods We calculated scales of effect for four metrics of habitat configuration and one metric of composition directly from species presence/absence data in online repositories. We did so for 102 species of mammals from 33 studies across the globe. Results Two metrics of configuration had significantly wider scales of effect than habitat composition, while the difference between the other two metrics of configuration and composition were not significant. The magnitude of the difference between metrics varied among samples, but none of the factors tested explained this variability. Conclusions If the scale of effect of a metric of composition is known, then a metric of configuration’s scale of effect can be expected to be roughly 15–20% wider. However, this pattern may not hold for metrics of configuration that do not measure attributes of the landscape that mediate species dispersal or that are correlated with the metric of composition.