Temporal sampling and abundance measurement influences support for occupancy–abundance relationships
Abstract
© 2019 John Wiley & Sons Ltd Aim: Species occupying a greater fraction of habitat patches tend to also be more locally abundant. The relationship between the fraction of occupied habitat patches and mean abundance (i.e. occupancy–abundance relationships) are a common macroecological observation, though they are far from ubiquitous. The aim of this work was to examine occupancy–abundance relationships in a large set of Finnish moth species, and determine the sensitivity of the strength and sign of these relationships to abundance estimation approach and temporal sampling scale. Location: Finland. Taxa: Lepidoptera. Methods: Using data on Finnish moth communities sampled over a period of 20 years, we examine species occupancy (fraction of sampled patches that were occupied) and mean abundance over time. We examine both intraspecific—the scaling of occupancy and local mean abundance for a single species—and interspecific—the scaling of occupancy and total mean abundance combining occupancy–abundance relationships for all species. Results: We found evidence for both intraspecific and interspecific occupancy–abundance relationships, dependent on the temporal sampling scale and how species abundance was estimated. The effect of seasonality on moth population dynamics was evident in the occupancy–abundance relationships, where finer temporal scales lead to ‘stronger’ relationships. Main conclusions: Together, we provide support for both intraspecific and interspecific occupancy–abundance relationships for a large set of Finnish moth species, but demonstrate sensitivity of support as a function of temporal sampling scale and abundance measurement.