Distributions of vascular plants in the Czech Republic. Part 1.

Despite a long history of botanical research on the Czech flora and the large amount of data on plant distribution that has been collected, there is still no comprehensive piece of work with distribution maps in this country and no distribution maps are available for more than a half of plant taxa. This paper is the first part of a series of publications prepared within the PLADIAS project, intended as the first step towards a complete atlas of the distribution of both native and alien vascular plants in the Czech Republic. It contains grid distribution maps of 75 taxa of the genera Achillea, Aegilops, Aira, Alopecurus, Avena, Bolboschoenus, Carex, Cladium, Elatine, Eleocharis, Eriophorum, Glyceria, Polypogon, Sclerochloa, Scheuchzeria, Sparganium, Tofieldia, Tragus and Viola. The maps are based on all available herbarium, literature and field records, which were stored at the CzechDistrib database, checked geographically and evaluated taxonomically, and shown in maps using the Central European mapping grid template derived from quadrants of 5 × 3 arc minutes (corresponding to approximately 5.5 × 5.9 km). Many of these maps resulted from detailed revisions carried out during the work on the Flora of the Czech Republic. Maps of taxonomically difficult groups are based solely or mainly on herbarium specimens revised by taxonomic experts. If useful, recent versus old records, native versus alien occurrences, or records based on revised herbarium specimens versus all other records are distinguished using different symbols. Records used for producing maps are listed in electronic appendices. The maps are accompanied by texts that include an outline of general distribution, information on habitats and specific details on the distribution in the country. Where appropriate, comments on taxonomy, biology or spatial and temporal dynamics in distribution are given.