JUN JUL AUG SEP OCT 



SPECIES 



EPHEMERALS 



COLPOMENIA 



PEREGRINA 



DIATOM 



FILM 



FAUCHEA 

 LACINIATA 



GIFFORDIA 

 MITCHELLAE 



PLEONOSPORIUM 

 VANOCOUVERIANUM 



PERENNIALS-RAPID GROWTH 



MONTH 

 NOV DEC 



JAN FEB MAR APR MAY 



PTEROSIPHONIA 

 DENDROIDEA 



RHODYMENIA 

 CALIFORNIA 



PERENNIALS-SLOW GROWTH 

 CORALLINES 

 GIGARTINA SPP. 



Periods of maximum colonization 

 Only slight colonization 

 Possible colonization 



Figure 16. Colonization times for the more abundant algal species that 

 recruited to artificial substrata in a kelp forest at Santa Cruz Island 

 (from Foster 1975a). 



northern sites near Santa Cruz (Foster 

 1982a), although abundance may vary at 

 particular sites affected by local 

 environmental changes such as sand 

 movement (Breda 1982). Overall, there 

 appears to be a general negative 

 correlation between the percentage cover 

 of Macrocystis canopies and the cover of 

 bottom canopy species. This may be a 

 direct result of shading on recruitment 

 and growth, and/or an indirect result of 

 overgrowth of these plants by sessile 

 invertebrates when light is low (Breda 

 1982). A composite graph of several 

 surveys at three localities in central 

 California shows that at times when 

 Macrocystis cover is high, the cover of 

 foliose alqae is low (Figure 18). 



1971a, Foster 1975a, 1982a). The two 

 species of Cal 1 iarthron (C. cheilospo - 

 roides and C. tuberculosum , Plate IF) are 

 the largest of the articulated corallines 

 along the west coast, and may have bran- 

 ches over 20 cm in length (Abbott and 

 Hollenberg 1976). These species, like 

 some of the more coarse, fleshy red algae 

 such as Gel idium robustum (Figure 17; 

 Barilotti and Silverthorne 1972), are 

 relatively slow growing and long-lived. 

 Cal 1 iarthron and related plants can also 

 be early colonizers on bare substrata 

 (Johansen and Austin 1970, Foster 1975a), 

 and this genus appears to maintain 

 coverage for many years (Johansen and 

 Austin 1970, Foster 1975a, Reed and Foster 

 1984). 



4.3.4.2 Articulated corallines . A 

 dense cover of articulated coralline algae 

 is common on the bottom in many kelp 

 forests (Johansen and Austin 1970, North 



Reed and Foster (1984) assessed the 

 effects of Calliarthron on the recruitment 

 of other species. In a site where 

 Macrocystis and Pterygophora canopies were 



53 



