Distribution and morphological variation of low-shore algal turfs

The distribution of three functional groups of algae (filamentous, corticat ed terete and calcareous articulated) was investigated in low-shore, turf-f orming assemblages from rocky shores in the western Mediterranean Sea (Ital y). Algae were sampled along shores from three different stations. Shores w ere either exposed to wave action or sheltered and were characterised by va rious inclinations of the rocky substratum (horizontal, sloping and vertica l). The hypotheses tested were: that the relative abundance of the three fu nctional groups of algae (1) varies between sheltered and exposed shores, ( 2) is influenced by substratum inclination and (3) that these distributions are consistent across stations. There was no clear relationship between th e morphology of turf-forming algae and shore characteristics. Covers of fil amentous, corticated terete and calcareous articulated algae differed among shores and stations, but patterns were not consistent across shores with s imilar exposure to waves and substratum inclination. Turfs often comprised algae with different morphologies, in a combination of anchor and epiphytic species. It is suggested that functional groups of algae, as currently ide ntified, are not effective in describing changes in distribution of algae b etween sheltered and exposed shores, when turf morphologies are considered. Future research on relationships between morphology and ecology of algae s hould consider the potential importance of positive interactions among asso ciated species, which could override responses of individual functional gro ups.