An analysis of structural pattern in an eelgrass (Zostera marina L.) amphipod community

摘要: The amphipods of eelgrass (Zostera marina L.) habitats near Beaufort N.C., were studied with the aims 1. 1) determining seasonal and spatial patterns abundance diversity amphipods, 2. 2) evaluating hypothesis that predation is generating observed patterns, and 3. 3) examining competition among in systems should be relatively unimportant. Four measures amphipod community structure examined — density, number species per sample, (H'), evenness (J) showed basically similar patterns. These are at their highest values during late winter decrease sharply spring months to summer lows. There increases all them fall. Seasonal generally from year somewhat within a single two study sites located different areas cstuarine system. Predator inclusion experiments using pinfish Lagodon rhomboides (L.) successful significant reductions abundances following two-week duration experiment. On other hand, fish exclusion mostly unsuccessful density as compared uncaged controls, due an increased activity decapod predators. The importance competitive interactions was evaluated three ways: matrix product moment correlation coefficients generated for common available sample data negative values, 2. 2) gut contents five food overlap, laboratory carried out more species. Evidence slight. In assemblage studied, there no dominant which monopolizes or space high densities. Increased pressure results pattern monotonic diversity. Removal one level predator (fish) this system appears result predatory levels (decapod crustaceans), thus continuing keep low.