Local variation among rocky subtidal habitats in the San Juan Archipelago: are differences in community structure associated with small-scale changes in abiotic factors?

Abstract

Previous studies have demonstrated that regional variation in community structure is largely driven by abiotic factors, but that these factors have less influence on community structure at smaller scales. We sought to investigate the potential role of select abiotic factors in regulating benthic communities at spatial scales ranging from 10 to 1000 meters. This was accomplished by comparing benthic point-intercept survey data against measurements of depth, slope, aspect and current flow. Results indicated that substrate depth and slope significantly correlated with observed differences in community composition, while current flow was marginally correlated with community composition. These results suggest that abiotic factors still play an important role in the structuring of biological communities at local scales.