Scrub communities along a climatic gradient in the southern Balkans: maquis, pseudomaquis and shibljak

The research deals with three scrub communities/formations in the southern Balkans, maquis, pseudomaquis and shibljak, and their changes along the main (macro)ecological gradient. We performed DCA analysis and, since the first axis correlates with climatic data, the projection of relevés on this axis was accepted as proxy for the (macro)ecological gradient, and the species turnover along this gradient was elaborated. Linear regression was used to test the turnover of life forms, chorotypes and the life strategy of species (syntaxonomical affiliation). It was found that life forms, except hemicryptophytes and nanophanerophytes, do not change significantly along the gradient change; most chorotypes change significantly; among species, life strategies (syntaxonomical affiliation), the proportion of species of deciduous and evergreen forests and scrub, as well as species of dry grassland, change significantly. The classification established three clusters, representing three formations and we tested differences among them. It was established that stenomediterranean and Eurasian species and species of perennial grasslands differentiate all three clusters and some groups only two of them. We found that discontinuous formations can be established along a continuous gradient. Communities were also classified within the present synsystematic system.