Popis: |
Some 3100 specimens of Characeae from herbarium collections and recent sampling programmes in Switzerland were redetermined and their provenance analysed, in order to investigate historical changes in frequency, distribution and current status of the species. Altitudinal and geographic distribution patterns of 27 taxa are described in 125 km2 grid squares covering Switzerland, and an analysis was made of species richness of Characeae in different grid squares. Data were available for approximately half (117 out of 262) of the grid squares covering Switzerland, showing that the recording effort had not been uniform. The lowland was better investigated than either the hills or the mountains. And 17 taxa were categorised as rare, on the basis that they were each known from |