The Dynamics of the Species-Area Relation in Marine Fouling Systems: 1. Biological Correlates of Changes in the Species-Area Slope

Abstract

After creating an archipelago of fouling panel islands, spanning 3 orders of magnitude in area, in Puget Sound, Washington [USA], colonization was monitored at frequent intervals for 1 3/4 yr. The larger panels fill up more slowly than the smaller panels and accumulate a larger fraction of the species pool. The latter would be expected even if the species pool were constant through time, but in this temperate region, the pool changes seasonally, further contributing to the increased species number on large panels. The relative proportion of edge-to-center space on panels appears in part to determine their relative rates of filling. Slopes of species-area curves computed for these artificial islands, rapidly rise for 10 wk, then remain fairly constant. Extinction rates are negligible in this 10-wk period; thus immigration differences are almost entirely responsible for the species-area relation. Both colonial and solitary species are present throughout the observation period: The former predominate initially, giving way to the latter.