White-tailed deer roadside behavior, wildlife warning reflectors, and highway mortality: G. H. Waring, J. L. Griffis & M. E. Vaughn, Applied Animal Behaviour Science, 29(1–4), 1991, pp 215–223

Abstract

An analysis of relationships between reproductive system, sporophyte production and rarity was performed using data on the British moss flora. This comprises 692 species, of which 177 species are considered rare in Britain. The results indicated that: (1) a higher proportion of monoecious than of dioecious species is rare; (2) a higher proportion of species not known to produce sporophytes than of fruiting species is rare; (3) absence of sporophytes is more prevalent among dioecious than monoecious species; and (4) a higher proportion of monoecious fruiting species than of dioecious fruiting species is rare.The incidence of rarity is thus lowest among dioecious fruiting species, and highest among species that are monoecious and produce sporophytes or are diecious and do not. These conclusions apply with particular force to a preliminary list of 76 British moss species considered to be rare at a world level. The results are illustrated with reference to the subfamily. Trichostomoideae (Pottiaceae), and are discussed in relation to possible origins of rarity.