Metazoan community structure in relation to the fractal dimensions of marine macroalgae

A measure of the complexity of a habitat independent of habitat type has long been required by benthic ecologists, particularly when comparisons between habitats or substrates need to be made and related to parameters of community structure. Using marine algae from the Isles of Scilly, UK, and their associated epifaunal communities as a testbed we have Investigated how the use of fractals may be one method of solving some of these problems The fractal dimensions of 4 species of macroalgae with a range of growth forms indicate an increasing order of complexity, which is paralleled by differences in the community composition and increasing diversity of 2 different size fractions of the epifaunal communities associated with each alga We conclude that the fractal dimensions of the habitat provide a numerical expression of complexity which is easy to calculate, is Independent of the nature of the habitat and is related to the scale at which the habitat may be viewed by the size hierarchies of animals which occupy it.