TitleALGAL RECRUITMENT AND THE MAINTENANCE OF A PLANT MOSAIC IN THE LOW INTERTIDAL REGION ON THE OREGON COAST
Publication TypeJournal Article
Year of Publication1993
AuthorsMenge, B, Farrell, TM, Olson, AM, Vantamelen, P, Turner, T
JournalJournal of Experimental Marine Biology and Ecology
Volume170
Pagination91-116
Type of ArticleJournal Article
ISSN0022-0981
Abstract

The role of recruitment of turf-forming algae in maintaining a low rocky intertidal plant mosaic on the central Oregon coast was investigated. Monthly samples suggested that spore release by one of the most abundant turf-forming red algae at wave-exposed sites (Constantinea simplex Setchell) occurred only in spring. In contrast, spore release by the two most abundant wave-sheltered red algae [Odonthalia floccosa (Esper) Falkenberg, Neorhodomela larix (Turner) Masuda] occurred at all times but winter. At wave-exposed sites, the turf-dominant colonized clearances frequently. At wave-sheltered sites, one dominant colonized frequently and the other turf-dominant colonized clearances infrequently. Experiments evaluated the rates of recruitment of these algae to manually cleared plots with respect to distance and direction from spore source, species of colonist, presence or absence of early colonists, wave turbulence (wave-exposed or wave-sheltered), and location. We also tested the effect of grazing at wave-exposed but not at wave-sheltered sites (where grazers were scarce). At one wave-exposed site, but not the other, recruitment of Constantinea within 1 x 2 m cleared areas responded differently to distance depending on its direction from the propagule source. Significant variation also occurred between clearances and sites. The effects of preemptive competition and grazing were not significant. At wave-protected sites, recruitment of Odonthalia but not Neorhodomela varied significantly with several factors. These included presence of early colonists, blocks (one site only), and sites. However, no variation in recruitment of either species occurred with respect to direction or distance from propagule source. Compared to Odonthalia, recruitment of Neorhodomela was extremely low suggesting that the high abundance of the latter depends on vegetative growth and long persistence. We conclude that recruitment processes can contribute to the maintenance of a high diversity mosaic at wave-exposed sites, but are of minor importance at wave-sheltered sites.

URL<Go to ISI>://WOS:A1993LR45600007
DOI10.1016/0022-0981(93)90131-7