The Effects of Canopy Shadings on Algal Recruitment and Growth in a Giant Kelp Forest

摘要: The subtidal (10-15 m) assemblage in the relatively sheltered giant kelp forest at Still- water Cove Carmel Bay, California, consists of perennial species forming three major vertical layers: a Macrocystis pyrifera surface canopy, dense subsurface canopy another kelp, Pterygophora californica, and an understory articulated encrusting coralline algae. canopies alone or combination can reduce bottom light to <3% (usually <1%) influx. effects reduction by these vegetation layers on algal recruitment subsequent growth were determined removing various combinations over 2-yr period, following changes relative appropriate controls. Removing both M. P. californica resulted moderate as well annual brown alga Desmarestia ligulata var. ligulata. None algae recruited into control areas where one left intact. Highest red occurred when plus branches removed. Removal latter had no significant effect. time year removed little effect composition colonization, noncalcareous primarily during short period spring. These results indicate that low levels physical biological disturbance Stillwater allow establishment few inhibit their own recruitment, invasion other species, shading. This contrasts with nearby forests subjected greater more frequent disturbance, characterized diverse species.