GBIF.org is a unique source of primary distribution data used in a multitude of studies worldwide. Derived from museums, herbaria, field researchers and citizen scientists, this data–as with any major source of biodiversity information–is prone to gaps and biases in taxonomic, geographical and temporal coverage.
In a study of invasions among South American aquatic plants, researchers assessed the state of data availability in GBIF and in literature. Based on a list of 40 native and 40 non-native species, the authors compile three datasets based on occurrences in GBIF.org, data manually extracted from literature, and the two combined, respectively. Initial comparisons showed significant differences between the two sources, and the combined dataset was deemed most reliable.
Based on this, the researchers generated maps of species distributions across 16 South American regions, finding the highest number of alien species in Argentina and Brazil. Adding a Human Influence Index layer, they further demonstrate that high risk species appear to cluster in areas of higher levels of anthropization, especially in coastal regions close to main ports.