COINCIDENCES BETWEEN DIFFERENT LANDSCAPE ECOLOGICAL ZONES AND GROWTH FORMS OF CEMBRAN PINE (PINUS-CEMBRA L) IN SUB-ALPINE HABITATS OF THE CENTRAL ALPS

Abstract

The `forgotten' depots of the European Nutcracker (Nucifraga c. caryocatactes) often `lead' to the development of tufts of Pinus cembra. In many cases the other individuals of such tufts are not suppressed by the fittest one, rather there is an intraspecific coexistence up to the senescent stage of the trees. There are fusions of separate trunks, and so frequently the individual history of older trees can only be reconstructed by studying sutures, crown structures or trunk cross sections. Different types of trunk fusions are worked out. By means of transect counting the occurrence of these `multiple trunk trees' is documented quantitatively in different landscape ecological zones of the Engadin region (the Grisons, Switzerland). The data base is 3024 counted microsites of Pinus cembra individuals arising from seeds, including 5272 living individuals. These `multiple trunk trees' significantly play an important role in the landscape ecological zones of recent glacier recession and at the alpine timberline. Their growth forms have a higher biomechanical stability.