RT info:eu-repo/semantics/article
T1 Spatial variation patterns of subtidal seaweed assemblages along a subtropical oceanic archipelago: thermal gradient vs herbivore pressure.
A1 Afonso Carrillo, Julio
A1 Sangil, Carlos
A1 Sansón Acedo, Marta
A2 BotánicaEcología y Fisiología Vegetal
A2 Botánica Marina
AB The structure and composition of subtidal rocky seaweed assemblages were studied at 69 sites on theCanary Islands (northeastern Atlantic). This group of islands are situated at the southern boundary of thewarm temperate region and adjacent to the cold waters from the northwest African coastal upwelling,which creates a difference of almost 2  C in surface seawater temperature from the eastern to thewestern islands. This thermal variation allows an examination of the transition between the warmtemperate and the tropical regions along this longitudinal gradient together with the hypothesisedFucales-dominated assemblages towards the eastern islands in contrast to the Dictyotales-dominatedassemblages towards the western ones. Environmental and biological parameters were considered inorder to investigate which were the main factors explaining spatial variation along the gradient ina multi-scaled approach. Although seventy-nine macroalgae were identified, 87.63% of the total meancover was due to six taxa (Lobophora variegata, nongeniculate corallines, Canistrocarpus cervicornis, Janiaadhaerens, Cystoseira abies-marina and Pseudolithoderma adriaticum). At a large scale, sea urchin densityexplained the highest variation in seaweed assemblages (26.94%), and its pattern of distribution acrossthe islands. The expected pattern of distribution according to the upwelling distance only occurred inrestricted areas of the Canarian Archipelago in absence of herbivore pressure and habitat degradation.Spatial variations within islands (medium scale) were mainly related to wave exposure, while at a smallscale these were mostly due to the degree of sedimentation.
PB Elsevier
YR 2011
FD 2011
LK http://riull.ull.es/xmlui/handle/915/28262
UL http://riull.ull.es/xmlui/handle/915/28262
LA en
DS Repositorio institucional de la Universidad de La Laguna
RD 08-nov-2024