Maintenance of diversity altered by a shift in dominant species: implications for species coexistence.

摘要: Diversity can be maintained by the biological characteristics of species within commu- nities, particularly dominant species. Invasions often result in shifts Despite number studies on invasion ecology, few have determined their long-term effect diversity. In present study, we coupled short- and to examine relationship between invasive (colonial ascidians or sea squirts) diversity discuss implications for coexistence. patterns 2 panel (1979 1982; 2003 2006), one conducted before establishment colonial ascidians, revealed an increase Short-term recruitment designed elucidate mechanisms behind observed our suggest contrasting methods maintaining Between 1979 1982, Mytilus edulis was a consistent spatial occupant whose hard shell provided secondary space col- onization other contrast, 2006 community dominated seasonally abundant Botrylloides violaceus lesser extent Didemnum vexil- lum, which do not provide substrate. These either senesce after reproduction undergo seasonal regression free colonization that coexistence has shifted from substrates is primary substrates. Addi- tionally, they undersaturated could support more species, particu- larly those utilize limited resource (free space).