Zonación del fitobentos en el litoral nordeste y este de La Palma (Islas Canarias)

Abstract

The zonation in five localities of the northeastern and eastern coasts of the island of La Palma is examined, showing the following characteristics: The snail Littorina striata and some Cyanophyceae occupy the littoral fringe; whereas in the upper eulittoral the barnacle Chthamalus stellatus dominates, together with Gelidium pusillum and Calothrix Crustacea; and in the middle eulittoral grow crustose brown algae and small turfs of red algae. In the lower eulittoral, and according to the degree of wave exposition, there are crustose coralline algae and turfs of red algae of genera Laurencia, Osmundea and Chondrophycus (exposed habitats), or turfs of the geniculate coralline algae Jania spp. and Corallina elongata (semiexposed habitats). Bands of Gelidiaceae {Pterocladiella capillacea, Gelidium arbuscula and G. canariense), occupy the upper sublittoral. Cystoseira abies-marina occurs throughout the entire littoral, but is usually limited to small populations among Gelidiaceae species or within tidepools at the lower eulittoral. Below the level of Gelidiaceae, geniculate coralline algae, Dictyotaceae and Asparagopsis taxiformis are dominant, being progressively replaced by denuded rocky bottoms ('blanquizales') originated by the activity of the sea urchin Diadema antillarum.