Multiscale spatial heterogeneity of macrobenthos of the White Sea tidal zone

Spatial distribution of macrobenthos of middle intertidal zone was studied in scale from centimetres to 30 kilometres along the coastline. The communi ty structure and distribution of the 5 most abundant species (Hydrobia ulva e, Mya arenaria, Macoma baltica, Peloscolex benedeni, Arenicola marina) wer e considered. Spatial heterogeneity of macrobenthos, estimated as mean diss imilarity between samples, kept constant in scale of centimetres-meters, bu t increased significantly when enlarged area is considered. Patterns of man y 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 (selfsimilar) patch pattern in wide range of scale from dozens of meters to several kilometres. Spatial correlations be tween species (the composition of assemblages) and between species and envi ronmental factors were also scale dependent. Some possible effects of scale on the observed spatial distribution of benthos an discussed, and multisca led analysis of biotic heterogeneity is concluded to be very fruitful.