Relative importance of recruitment and post-settlement processes in the maintenance of coral assemblages in an insular, fragmented reef system
Résumé
We compared relationships among distribution patterns of recruits, juveniles and adults of 3 different coral families with distinct life history traits at multiple spatial scales in an insular, fragmented reef system characterized by recurrent disturbances to better understand recruitment and maintenance processes of reef corals. The goal of our study was to detect at what scale most abundance variation occurred, and if this was consistent among life cycle stages and life histories. Results demonstrate a very high spatial variability of recruitment rates at the regional, insular and local hierarchical levels, with some locations displaying much higher recruitment rates than others, in 2 successive seasons. Juvenile and adult abundances were less variable, and most of the variation occurred at a local level for these life cycle stages. Recruit assemblage composition differed from juvenile and adult ones, which were much more similar. Moreover, abundance variation of recruits was unrelated to variation of juveniles and adults, but juvenile abundance was significantly correlated with adult abundance across all levels. These results have important implications for conservation planning, showing that some locations have better recovery abilities, and revealing the paramount importance of events occurring during the first weeks and months after settlement on the distribution of adults at regional, island and local levels, thus confirming the significance of local processes in shaping coral assemblages distribution and maintenance.