Zonation schemes on sandy shores: a multivariate approach  <B>Zonation schemes on sandy shores: a multivariate approach</B><P>D. Raffaelli(1), I. Karakassis(2) and A. Galloway(1)</B><I><P> (1) Culterty Field Station, University of Aberdeen, Newburgh</I><I><B>,</B></I><B> </B><I>Aberdeen UK;<BR> (2) Institute of Marine Biology, Heraklion, Crete, Greece</I><B><P> Key words</B>: Beach Fauna; lntertidal; Multivariate method;<B> </B>Zonation scheme<B><P> INTRODUCTION</B><P> Zonation patterns reflect the restriction of species of particular sections of environmental gradients. In<B> </B>terrestrial systems, altitudinal, continental moisture and latitudinal gradients often stretch over 10s or 100s km<B> </B>(Whittaker, 1975), so that the gradient is often fragmented and zonation patterns may not be immediately obvious. In contrast, zonation is the most visually striking feature of the relatively short intertidal gradient occurring on rocky shores. It is not suprising that zonation patterns have historically provided a major focus for much intertidal work, both in terms of the analysis of static patterns (e.g., Stephenson & Stephenson, 1972; Lewis, 1964) and dynamic processes (e.g., Connell, 1972).<BR> One of the most important observations of earlier intertidal researchers was the occurrence of three zones consistently found world-wide on rocky shores. These so-called "universal features of zonation" (Stephenson & Stephenson, 1949) can be summarised as: an upper littorinid/black lichen zone; a mid shore characterized by barnacles; a lower zone supporting large brown algae (temperate regions) or ascidians and red algae (warm-temperate regions). The actual species present vary with location but the same types of organism characterize each zone. The significance and usefulness of such a scheme is that intertidal ecologists from different geographical areas have common<B> </B>reference points on the shore defined not by tidal heights, which are difficult to measure and equivalence between shores, but by easily recognized biological features.<P> Correspondence address: D. Raffaelli, Culterty Field Station, University of Aberdeen, Newburgh, Aberdeen AB41 OAA, UK.<I><P> J. Exp. Mar. Biol. Ecol., </I>148 (1991) 241-253<P>