Resumo

RICO, Alicia; LANAS, Paola  e  LOPEZ-GAPPA, Juan. Colonization potential of the genus Ulva (Chlorophyta, Ulvales) in Comodoro Rivadavia Harbor (Chubut, Argentina). Cienc. mar [online]. 2005, vol.31, n.4, pp.719-735. ISSN 0185-3880.

Temporal and spatial changes in the coverage of five Ulva L. species (U. prolifera O.F. Müller, U. intestinalis L., U. hookeriana (Kützing) Hayden et al., U. compressa L. and U. linza L.) were analyzed on rocky substrata experimentally immersed in Comodoro Rivadavia Harbor (Argentina). Colonization was studied during an annual period at three levels: upper intertidal, middle intertidal and subtidal. Coverage was significantly higher in the middle intertidal and subtidal levels than in the upper intertidal level, where all species of Ulva were absent. Seasonal changes were also significant: coverage in summer and spring was significantly higher than in autumn and winter. Most species showed high spatial variability among replicates from the same level and season. Zonation patterns within the harbor differed from those observed in natural areas, probably due to low wave exposure and its interaction with herbivory and desiccation stress. Colonization patterns observed in this study indicate niche segregation in closely related species of the genus Ulva.

Palavras-chave : Ulva; Chlorophyta; Comodoro Rivadavia Harbor; Patagonia; Argentina.