Improving accuracy of Red List assessments using open access species occurrence data

Study uses GBIF-mediated occurrences to re-assess conservation status of rare fern, dropping suggested designation from Endangered to Vulnerable

Data resources used via GBIF : 128 species occurrences
Cibotium arachnoideum
Cibotium arachnoideum (C.Chr.) Holttum collected on Mt. Kinabalu, Borneo, Malaysia. Cropped specimen photo via the National Museum of Natural History, Smithsonian Institution.

Assessing the conservation status and extinction risk of species for inclusion in the IUCN Red List of Threatened Species requires high-quality species occurrence data to apply criterion B, measuring the extent and area of occurrence of assessed species. With more than 1.6 billion records readily available, assessors are increasingly using GBIF-mediated data for species red-listing.

In this paper, authors from Indonesia re-evaluated a previous assessment of the fern Cibotium arachnoideum that relied only on specimens from a single herbarium, categorizing the species as endangered (EN). Adding additional occurrence data from GBIF, the present study more than tripled the number of records included in the assessment.

Using just 41 occurrences, the authors calculated Extent (EOO) and Area of Occurrence (AOO) using the GeoCAT tool, reaching values far higher than the previous assessment, qualifying C. arachnoideum for a Near Threatened (NT) designation. They further assessed the species under other criteria, and by modelling the suitable habitat of the fern, they showed that future habitat conversion is unlikely to be a serious threat.

Based on the combined results, the authors disagree with the previous EN designation and instead suggest that C. arachnoideum be included in the Red List as Vulnerable (VU), a lower risk category.

Robiansyah I and Wardani W (2020) Increasing accuracy: The advantage of using open access species occurrence database in the Red List assessment. Biodiversitas Journal of Biological Diversity. UNS Solo 21(8). Available at: