The ecology of intertidal algal crusts: variation within a functional group

Early development of algal assemblages under different regimes of physical and biotic factors on a seasonal tropical rocky shore

“…Organisms inhabiting tropical intertidal shores may experience intense heat, desiccation and radiation stress during emersion (Moore 1972, Levings & Garrity 1984, Williams 1994, Williams & Morritt 1995. Many encrusting algae (with the exception of the coralline crusts) are thought to be comparatively tolerant of physical stress (Lubchenco & Cubit 1980, Littler et al 1983, Menge et al 1983, Levings & Garrity 1984, Quinn 1988, Dethier 1994, although there is little direct evidence that, as a group, they are more tolerant of stress than their erect counterparts. During periods of increased physical stress on tropical shores, the abundance and/or upper limits of distribution of erect and encrusting algae have been shown to decrease (Lawson 1966, Hodgkiss 1984, Lubchenco et al 1984, Williams 1993a.…”

“…Encrusting algae, therefore, appear to be more resistant to physical stress than erect species (but see Buschmann 1990). The greater desiccation tolerance of fleshy encrusting algae may be partially due to their low exposed surface area (see also Dromgoole 1980, Dethier 1994. Coralline crusts share the low specific surface of other encrusting algae, but under natural conditions have a very low water content (Dethler 1994, Kaehler 1996 and may subsequently be more susceptible to desiccation stress.…”

“…Zanefeld 1937, Moore 1939, Doty 1946, Lewis 1964, Frank 1965, Dayton 1971, Connell 1972 Buschmann 1990) and it has been implied that, towards their upper vertical limits, macroalgae are restricted by physiological intolerances during low tide (reviewed by Norton 1985, Underwood 1985, 1991, but see Underwood 1980. Physiological tolerances, however, may vary between algal functional groups (Dethier 1994), and between individual species (Schonbeck & Norton 1978, Dethier 1994, as well as ontogenetically with the size and developmental stage of the macroalgae (Hruby & Norton 1979, Norton 1986, Davison et al 1993). …”

Interplay of encrusting coralline algae and sea urchins in maintaining alternative habitats

“…Others (Bertness et al 1983, Sebens 1983, Masaki et al 1984, Johnson & Mann 1986, Dethier 1994 and references therein) have shown that crusts were able to reduce settlement of potential competitors, suggesting that their persistence does not strictly depend on the control of erect species by grazers.…”

Physiological responses to environmental variation in intertidal red algae: does thallus morphology matter?

“…Although several studies have examined the ecological processes determining the distribution and abundance of these species in the intertidal zone (Mathieson & Burns 1971, Burns & Mathieson 1972, Lubchenco 1980, Green 1983, Dudgeon & Johnson 1992, none of these studies included the crustose tetrasporophytic stage (=Petrocelis; West et al 1977, Guiry & West 1983) of M. stellatus, either because the research was conducted prior to the discovery of a crustose tetrasporophyte in the life history of the species, or because the crusts were not recognized in the study areas. In fact, very little is known about the ecology or physiology of the crustose tetrasporophytic stage of most species in the genus Mastocarpus; a notable exception being M. papillatus (Paine et al 1979, Slocum 1980, Littler & Arnold 1982, Zupan & West 1990, Dethier 1994. Our understanding of the ecological and evolutionary significance of heteromorphic life histories among macroalgae in general, and the ecology of the 'Chondrus-Mastocarpus' mixed assemblage of low intertidal rocky shores in the north Atlantic Ocean in particular, is enhanced by comparative physiological and ecological studies of M. stellatus.…”