Historically, the GBIF.org home page has displayed a number to indicate how many species are represented in data records within the portal. We have decided not to continue this practice, since any number is misleading in some way.
It is however useful to understand and monitor GBIF’s coverage of the tree of life. We are working to deliver the most comprehensive view we can of available evidence for species distributions and of material held in the world’s natural history collections. Knowing how many species are already represented in available data is an important indication of progress towards this goal.
There are two main complications to giving a count of species included in GBIF data:
- The different classes of dataset mobilized through the network
- The gaps in available taxonomic datasets
For the first of these, it is important to understand that GBIF supports mobilization both for georeferenced evidence of species occurrences (as occurrence-only and sampling-event datasets) and also for species checklists. Species checklists may include implicit evidence of species occurrence in a particular region (and we plan to make more use of these datasets in this context) but many checklist datasets exist to present basic information on the names and classification for species or to document non-geographic properties and characteristics associated with species. In particular, GBIF treats the entire Catalogue of Life as a checklist dataset.
Most users visit GBIF.org to access geospatial information or to locate specimen records. For such users, the total number of species represented in all GBIF datasets is not significant. The most important measure of GBIF’s coverage is the number of species for which GBIF has evidence that the species was recorded at particular times and places.
The second issue relates to the fact that, even with the Catalogue of Life and other taxonomic resources, there are still significant taxonomic groups for which there is no authoritative reviewed checklist. This particularly affects a number of large and important insect, plant and fungal groups. GBIF has no reliable way to determine the actual number of species for these groups. In such cases, in the absence of better information, we are obliged to treat each scientific name as a separate candidate species, even though many of these names are certainly synonyms for a smaller number of species. We are currently working with Catalogue of Life and other partners to try to deliver a more seamless and complete working checklist of all species but, right now, our view of the available data includes hundreds of thousands of scientific names which may or may not be accepted species.
With this explanation in place, here are some numbers that indicate the current coverage of species within GBIF:
|Counts as of August 2017 (links lead to live counts)||Description|
|1,639,624||The number of reviewed species included in the latest Catalogue of Life checklist. This is an external baseline for the number of described species in the taxonomic groups currently covered by the Catalogue of Life.|
|968,021||The number of reviewed species from the latest Catalogue of Life checklist for which GBIF also has at least one record from an occurrence-only or sampling-event dataset|
|2,528,677||The total number of reviewed species and unreviewed scientific names (candidate species) currently known to GBIF.|
|1,519,755||The total number of reviewed species and unreviewed scientific names for which GBIF also has at least one record from an occurrence-only or sampling-event dataset|