Temporal variation in species‐area curves for invertebrates in clumps of an intertidal mussel

Abstract

We examined the temporal variation in the relationships between the number of invertebrate species, and of total individuals inhabiting clumps of the intertidal mussel Brachidontes rostratus and the area of the clumps We collected clumps in four seasons ‐ autumn, winter, spring and summer ‐ from a rocky shore in south‐eastern Australia Positive curvilinear relationships between species number and area were recorded for all seasons but fewer species for a given area were found in autumn and summer compared with winter and spring These species‐area relationships were different from those predicted from a passive sampling model (Random Placement Model) Positive relationships between number of individuals and area were also recorded but these did not vary between seasons There was no short‐term difference (i e between phases of tide and day) in species or individual number in clumps Seasonal variation, and small‐scale spatial unpredictability in recruitment patterns are potentially important determinants of species numbers in this system The seasonal differences we have recorded for mussel clumps suggest that future studies on island systems particularly in marine habitats should consider temporal variation in species‐area relationships and that conclusions from previous comparisons of species‐area curves based on one‐off sampling must only be tentative