ibclogo XVI International Botanical Congess


Abstract Number: 3025
Session = 20.7.1


WHAT ARE THE ATTRIBUTES AND PATTERNS OF RARE BRYOPHYTES?


Dale Vitt & René J. Belland, Department of Biological Sciences, University of Alberta


About 25% of any moss flora can be considered locally rare. These rare species are nonrandomly distributed among ecological, morphological, and taxonomic groups. Rare species occur most frequently in certain micro- and mesohabitats, the latter defined as non-random sets of microhabitats. In Alberta, 74% of locally rare mosses occur on restricted mesohabitats. These small, sometimes isolated mesohabitats are critical for preservation of rare species. In peatlands of western Canada, species richness is highly variable at the site level, and species turnover varies considerably between peatland types. Thus management of this local rarity must be tailored to specific peatland types and cannot be extrapolated to wetland habitats in general. At the site level, species richness is best predicted by the distribution of microhabitats, while at regional or landscape level, species richness is best predicted by quantity and quality of mesohabitats.


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