Test panels were installed in January 2008 and monitored May 2008 through August 2009. The successional state of the panels at the end of monitoring was evaluated before comparisons in community composition, taxa richness, and abundance were made. The typical successional trajectory after a disturbance in a rocky intertidal zone is that ephemeral algae and sessile invertebrates (like barnacles) appear first, and are gradually replaced by larger perennial algae. However, the rate of succession is sometimes more difficult to predict than the trajectory or outcome - it can be highly variable and depends on the timing and magnitude of the initial colonizers. The rate of succession of the test panels in this study was evaluated by testing convergence of algae and invertebrates among the reference, control, and flat smooth panels. Reference sections of seawall were used to represent a mature “late-successional state.”
Convergence is the
length of time it takes for a disturbance or clearing to converge with the
surrounding community and can take months
to years in a rocky
intertidal habitat. Variability of a
recently disturbed, early successional community is typically higher than an
established late successional community. The graph shows comparisons of variability within the reference to the variability within the control and flat smooth panels and shows that the new susbrata represented by the habitat panels converged with reference (original) sections of seawall by the summer of 2009.