Data/hora: 08/06/2024 10:57:54

Provedor de dados: | 97
País: | Chile
Título: | Independent effects of grazing and tide pool habitats on the early colonisation of an intertidal community on western Antarctic Peninsula
Autores: | Segovia-Rivera,V; Valdivia,N.
Data: | 2016-01-01
Ano: | 2016
Palavras-chave: | Antarctica; Environmental stress model; Grazing; Herbivory; Intertidal; Nacella polaris; Periphyton.
Resumo: | BACKGROUND: Prevailing environmental conditions can modulate the structuring role of biotic interactions. In intertidal habitats, less stressful environmental conditions and/or higher grazer densities may allow grazing effects to be stronger in tide pools than on emergent rocks. To test this hypothesis, we conducted a manipulative experiment on an intertidal rocky shore in Fildes Bay, King George Island, in which the effect of the dominant grazer Nacella polaris on the structure of benthic periphyton communities was compared between emergent rock and tide pool habitats. Also, we determined the spatial variation in density, weight, and maximum length of individuals of N. polaris in both habitats RESULTS: The density of N. polaris was significantly larger in tide pools than on emergent rocks. Contrarily, we observed no significant differences in morphological parameters of N. polaris between both habitats or between intertidal elevations. In the manipulative study, we observed a greater taxonomic richness, diversity, and abundance of periphyton on emergent rocks than in tide pools. These variables also showed, in comparison with control areas, significantly higher values in experimental areas where herbivores were excluded by means of stainless-steel fences. The effects of habitat and grazer exclusion treatments were independent of each other, as no statistically significant interaction between both factors was observed CONCLUSIONS: Our results showed significant, but independent, effects of tide pool habitats and grazing on the early colonisation of these assemblages. Albeit the grazing effects of other herbivores such as amphipods and small gastropods cannot be ruled out, we suggest that traits of N. polaris, such as high mobility and circadian activity, allow this species to exert a firm control on the intertidal Antarctic assemblages across local environmental conditions.
Tipo: | Journal article
Idioma: | Inglês
Identificador: | http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2016000100003
Editor: | Sociedad de Biología de Chile
Formato: | text/html
Fonte: | Revista chilena de historia natural  v.89 2016