Abstract

Quantifying the fundamental unit of biogeography and why it matters
Track: Conservation
Authors: John Donoghue II

Geographic range size is a key criterion for determining a species' conservation status and prioritization; yet, many methods of estimating range size exist. As different methods can lead to drastic differences in species richness and extinction risk estimates, how we measure range size is profoundly important. We used a large dataset of New World plant species to investigate several popular approaches for estimating geographic range sizes and distributions of species. We found the area defined by a convex hull to be a fairly good predictor of range size, while estimates from popular maxent models were highly sensitive to the layers and threshold used to create presence/absence maps. Finally, species richness maps created from the range maps of various approaches were markedly different than maps derived using typical expert range maps, so we offer some best practices for estimating a species' geographic range size and distribution.