Dep. Hydrobiology, Biological Faculty, M.V.Lomonosov Moscow University, Vorob'evy Gory, Moscow 119899, Russia

Abstract

Spatial distribution of macrobenthos of middle intertidal zone was studied in scale from centimetres to 30 kilometres along the coastline. The community structure and distribution of 5 the most abundant species (Hydrobia ulvae, Mya arenaria, Macoma baltica, Peloscolex benedeni, Arenicola marina) were considered. Spatial heterogeneity of macrobenthos, estimated as mean dissimilarity between samples, kept constant in scale of centimetres - meters, but increased significantly when enlarged area is considered. Patterns of many species changed with scale from random mosaic to more or less pronounced patchiness, whereas the density of H.ulvae and the structure of the whole community demonstrated fractal (self-similar) patch pattern in wide range of scale from dozens of meters to several kilometres. Spatial correlations between species (the composition of assemblages) and between species and environmental factors were also scale dependent. Some possible effects of scale on the observed spatial distribution of benthos are discussed, and multiscaled analysis of biotic heterogeneity is concluded to be very fruitful.