Zonation of Lichens on a Rocky Seashore on Fidalgo Island, Washington
1988; American Bryological and Lichenological Society; Volume: 91; Issue: 3 Linguagem: Inglês
10.2307/3243214
ISSN1938-4378
Autores Tópico(s)Marine and coastal plant biology
ResumoA quantitative study of marine and maritime lichens on serpentine rock on the north shore of Washington Park, Fidalgo Island (Skagit County), Washington, revealed that major changes in the prominence values (or conspicuousness in the field) of a number of lichens and asssociated organisms occurred in the vicinity of certain elevations. This finding suggests that critical changes in environmental conditions occurred at or near these elevations. When the site was viewed as a whole, the zonation was rather indistinct, primarily because freshwater seepages modified marine- controlled zonation patterns. In addition, patchy patterns offeeding by marine snails and manuring by birds modified the zonal distributions. Upper or lower limits of certain taxa, or of conspicuous belts of particular taxa, were used in this study to define zone boundaries. General features of zonation at this site, in nonseepage areas, were similar in some respects to those in British studies. In a complementary report (Ryan 1988), a list of lichens on serpentine rock on the north shore of Fidalgo Island, Washington is presented, with notes on taxonomy, description of the site, and discussion of the composition of the lichen flora there. The present paper focuses on the distribution of these lichens at the site. The major goal of this part of the study was to conduct an intensive quantita- tive survey of the lichens on this rocky seashore in order to define boundaries of zones relative to height on shore and correlate these zones with those in previous studies, and to examine, to some extent,
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