Plant distribution data in NatureServe Explorer are based on a variety of sources. With a few exceptions, the state and province distribution records of species shown with corresponding subnational conservation status information (i.e., subnational ranks) are based on information received from the respective natural heritage member program. For vascular plants, most other state and province records, especially for more common species, are based on distribution information shown in from various prepublication drafts of the Synthesis of the North American Flora (Kartesz, 1999); some revisions to those records have been made by NatureServe botanists in accordance with more recent information. may be required to conform with the future versions of that publication. A small number of distribution records are added from other sources, such as the U.S. Fish and Wildlife Service, the Canadian Museum of Nature, and botanical literature reviewed by NatureServe botanists. For vascular plants first described after 1999, most state and province records without subnational ranks are based on the distribution reported in concept reference.
Primary Vascular Plant Distribution Reference:
Kartesz JT. 1999. A synonymized checklist and atlas with biological attributes for the vascular flora of the United States, Canada, and Greenland. In: Kartesz JT, Meacham CA. Synthesis of the North American Flora, Version 1.0. Chapel Hill: North Carolina Botanical Garden.
For Vertebrates and Invertebrates
Animal distribution data in NatureServe Explorer are derived from many sources. For vertebrates and certain well-studied groups of invertebrates, the primary sources are scientific literature, web sites, experts, and information from local data centers. Many of the same sources used for taxonomy and nomenclature are consulted for distribution information. In turn, much of the published information is based on museum specimen records and, especially for birds, reliably documented observation records. Review of the available literature and other sources is done by NatureServe zoologists and by other experts contracted to develop this information, who supplement their literature research with personal knowledge. Over time, state and province distribution lists are refined as local data centers obtain new records for species not previously recognized in their jurisdictions and transfer this new information to the NatureServe's central databases during the annual data exchange process. For invertebrates in less well-studied groups, the state and province data in the central databases come from local natural heritage zoologists who derive their knowledge from the sources mentioned above, especially local experts and museum collections.