Data curation on species occurrence records placed in unrecognized distributions shapes our understanding of plant bioclimatic niches

Resumen

The limitations, biases and uncertainties associated with occurrence records often limit their utility to describe species’ realised bioclimatic niches. We assess changes in the perception of the realised niche of 156,500 terrestrial vascular plant species when excluding records that fall out of their recognized distribution (either native or introduced) as documented by their biogeographical status in Plants of the World Online. Filtering records following the species' geographical distribution recognised by experts results in a distortion of the representation of their niches, in some cases reducing the bioclimatic space occupied by more than half. This reduction affected between 20-40% of the species across orders, and raised up to 68% for Osmundales and Pinales or 83% in Equisetales. While most of the species evaluated (96%) only presented records in native botanical countries, about 90% of the species with introduced records expanded their realised niche beyond native climatic conditions. This calls for caution when selecting occurrence records from public repositories to conduct massive analyses on terrestrial plants. Validating these niche discrepancies derived from the curation process will allow drawing robust conclusions about species’ responses to environmental changes.