Photosynthetic response and zonation of three species of Gelidiales from Tenerife, Canary Islands

Abstract

Three species of Gelidiales (Gelidium arbuscula, Gelidium canariense and Pterocladiella capillacea) (Rhodophyta) were selected due to their abundance in the marine lower intertidal of the north coast of the island of Tenerife (Canary Islands), to assess, using PAM fluorescence, the importance of irradiance and exposure to air on vertical distribution. We compared tolerance to emersion by air-drying fronds under simulated emersion, and results suggest that recovery of photosynthesis after emersion plays a major role in the vertical distribution of these three species. Morphological traits such as clumped fronds explain the higher tolerances, and reduced water loss of the species upper on the shore. Local differences between sites may be related to slight differences in the light regime related to topography.

Keywords

• canary islands
• ecophysiology
• gelidiales
• gelidium
• photosynthesis
• pterocladiella