title: Estimating species diversity and distribution in the era of Big Data: to what extent can we trust public databases?
abstract: Massive digitalization of natural history collections is now leading to a steep accumulation of publicly available species distribution data. However, taxonomic errors and geographical uncertainty of species occurrence records are now acknowledged by the scientific community - putting into question to what extent such data can be used to unveil correct patterns of biodiversity and distribution. We explore this question through quantitative and qualitative analyses of uncleaned versus manually verified datasets of species distribution records across different spatial scales.
  
  
  
  The American tropics.
  
  
  
  As test case we used the plant tribe Cinchoneae (Rubiaceae). We compiled four datasets of species occurrences: one created manually and verified through classical taxonomic work, and the rest derived from GBIF under different cleaning and filling schemes. We used new bioinformatic tools to code species into grids, ecoregions, and biomes following WWF's classification. We analysed species richness and altitudinal ranges of the species.
  
  
  
  Altitudinal ranges for species and genera were correctly inferred even without manual data cleaning and filling. However, erroneous records affected spatial patterns of species richness. They led to an overestimation of species richness in certain areas outside the centres of diversity in the clade. The location of many of these areas comprised the geographical midpoint of countries and political subdivisions, assigned long after the specimens had been collected.
  
  
  
  Open databases and integrative bioinformatic tools allow a rapid approximation of large-scale patterns of biodiversity across space and altitudinal ranges. We found that geographic inaccuracy affects diversity patterns more than taxonomic uncertainties, often leading to false positives, i.e. overestimating species richness in relatively species poor regions. Public databases for species distribution are valuable and should be more explored, but under scrutiny and validation by taxonomic experts. We suggest that database managers implement easy ways of community feedback on data quality.
authors.affiliation: Natural History Museum of Denmark University of Copenhagen Copenhagen Denmark; Herbario Nacional de Bolivia Universidad Mayor de San Andres La Paz Bolivia.
authors.forename: Carla
authors.identifier: 0000-0002-1268-7140
authors.initials: C
authors.lastname: Maldonado
authors.affiliation: Natural History Museum of Denmark University of Copenhagen Copenhagen Denmark; Instituto de Ecología Universidad Mayor de San Andres La Paz Bolivia.
authors.forename: Carlos I
authors.initials: CI
authors.lastname: Molina
authors.affiliation: Department of Biological and Environmental Sciences University of Gothenburg Gothenburg Sweden.
authors.forename: Alexander
authors.initials: A
authors.lastname: Zizka
authors.affiliation: Department of Biological and Environmental Sciences University of Gothenburg Gothenburg Sweden.
authors.forename: Claes
authors.initials: C
authors.lastname: Persson
authors.affiliation: Missouri Botanical Garden University of Missouri-St. Louis St. Louis MS USA.
authors.forename: Charlotte M
authors.initials: CM
authors.lastname: Taylor
authors.affiliation: Museo de Historia Natural Universidad Nacional Mayor de San Marcos Lima Peru.
authors.forename: Joaquina
authors.initials: J
authors.lastname: Albán
authors.affiliation: Museo de Historia Natural Universidad Nacional Mayor de San Marcos Lima Peru; Departamento de Biologia Vegetal Universidade Estadual de Campinas Sao Paulo Brazil.
authors.forename: Eder
authors.initials: E
authors.lastname: Chilquillo
authors.affiliation: Natural History Museum of Denmark University of Copenhagen Copenhagen Denmark.
authors.forename: Nina
authors.initials: N
authors.lastname: Rønsted
authors.affiliation: Department of Biological and Environmental Sciences University of Gothenburg Gothenburg Sweden; Gothenburg Botanical Garden Gothenburg Sweden.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Antonelli
keywords: Cinchoneae; GBIF; Rubiaceae; SpeciesGeoCoder; data quality; occurrence data; species richness