sampbias , a method for quantifying geographic sampling biases in species distribution data

Ecography, vol. 44, pp. 25–32

Abstract

Geo‐referenced species occurrences from public databases have become essential to biodiversity research and conservation. However, geographical biases are widely recognized as a factor limiting the usefulness of such data for understanding species diversity and distribution. In particular, differences in sampling intensity across a landscape due to differences in human accessibility are ubiquitous but may differ in strength among taxonomic groups and data sets. Although several factors have been described to influence human access (such as presence of roads, rivers, airports and cities), quantifying their specific and combined effects on recorded occurrence data remains challenging. Here we present sampbias , an algorithm and software for quantifying the effect of accessibility biases in species occurrence data sets. sampbias uses a Bayesian approach to estimate how sampling rates vary as a function of proximity to one or multiple bias factors. The results are comparable among bias factors and data sets. We demonstrate the use of sampbias on a data set of mammal occurrences from the island of Borneo, showing a high biasing effect of cities and a moderate effect of roads and airports. sampbias is implemented as a well‐documented, open‐access and user‐friendly R package that we hope will become a standard tool for anyone working with species occurrences in ecology, evolution, conservation and related fields.

Authors 3

1. Alexander Zizka corresponding Aachen Naturalis Biodiversity Center

   Leiden University · Leipzig University · German Centre for Integrative Biodiversity Research · Naturalis Biodiversity Center

   Affiliation as printed

   German Centre for Integrative Biodiversity Research Halle‐Jena‐Leipzig (iDiv), Univ. of Leipzig Leipzig Germany

   Naturalis Biodiversity Center, Leiden Univ. Leiden The Netherlands

   German Centre for Integrative Biodiversity Research Halle-Jena-Leipzig (iDiv), Univ. of Leipzig, Leipzig, Germany

   Naturalis Biodiversity Center, Leiden Univ., Leiden, The Netherlands

2. Alexandre Antonelli

   University of Gothenburg · Royal Botanic Gardens, Kew

   Affiliation as printed

   Dept for Biological and Environmental Sciences, Univ. of Gothenburg Gothenburg Sweden

   Gothenburg Global Biodiversity Centre, Univ. of Gothenburg Gothenburg Sweden

   Royal Botanic Gardens Kew Surrey United Kingdom

   Dept for Biological and Environmental Sciences, Univ. of Gothenburg, Gothenburg, Sweden

   Gothenburg Global Biodiversity Centre, Univ. of Gothenburg, Gothenburg, Sweden

   Royal Botanic Gardens Kew, Surrey, United Kingdom

3. Daniele Silvestro

   University of Gothenburg · University of Fribourg

   Affiliation as printed

   Dept for Biological and Environmental Sciences, Univ. of Gothenburg Gothenburg Sweden

   Dept of Biology, Univ. of Fribourg Fribourg Switzerland

   Gothenburg Global Biodiversity Centre, Univ. of Gothenburg Gothenburg Sweden

   Dept for Biological and Environmental Sciences, Univ. of Gothenburg, Gothenburg, Sweden

   Dept of Biology, Univ. of Fribourg, Fribourg, Switzerland

   Gothenburg Global Biodiversity Centre, Univ. of Gothenburg, Gothenburg, Sweden