Wide Disjunctions

A study of Cladonia cervicornis (Achar.) Flotow from two widely disjunct populations in California, one from coastal Mendocino County and one from the foothills of the Sierra Nevada in Amador County, revealed a difference in the frequency of occurrence of the depside atranorin [245] (see Fig. 2.76) (Hammer and Ahti, 1990). The compound, considered to be a primitive feature of this lichen species, was present in 80% of the... 

The availability of North American specimens of Glehnia made it possible to compare coumarin and acetylene profiles of this widely disjunct system (Hiraoka et al., 2002). Analysis of plant material collected from four widely separated sites, that is, northern California, central Oregon, northern Washington, and northeastern Queen Charlotte Islands, British Columbia, revealed a profile characterized by low levels of furanocoumarins and a comparatively high level of panaxynol. The results are similar to those that characterize the southern Japanese form. The North American... 

Phylogeography of Cavernularia hultenii evidence of slow genetic drift in a widely disjunct lichen. Molecular Ecology 12, 1473-1486. 

Some years ago, Breckon and Barbour (1974) published a review of beach vegetation for the North American Pacihc Coast that contains detailed information on a wide variety of strand taxa. A number of taxa discussed in their work have disjunct distributions, involving other continental beaches suggesting other taxa worthy of detailed phytogeographic study. 

The natural range of the Eurasian mink (Mustela lutreola) extends through much of central Europe, Ukraine, Belarus, and western Russia, with a disjunct population in Erance. This species has become widely extirpated from much of its natural range, through a combination of habitat changes and excessive trapping. 

Wide intercontinental and disjunct ranges could also have been created either by many long-distance (e.g. intercontinental) events, or few long-distance but a lot of dispersal over medium or short distances founding intermediate populations... 

Fifty-seven taxa of the caatinga (c.18% of the total taxa) are disjunct between two or more areas. The most conspicuous disjunction involves three widely separate areas, the Ibiapaba plateau, the Raso da Catarina and the dunes of the Sao Francisco river, a pattern shown by 13 species (Figure 6.8). Most of these species are restricted to the caatinga and occur in different combinations... 

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