EFFECT OF ENVIRONMENTAL VARIABLES IN THE DISTRIBUTION OF TREE SPECIES IN THE IGUAÇU NATIONAL PARK

ABSTRACT The knowledge of the environmental variable seffect on the distribution of tree species is of great importance, since it contributes to a greater efficiency on the management of forests and on the conservation of degraded areas. In order to identify these effects on native species from the western region of Parana, 21 plots of 2,000 m2 were installed in the Iguacu National Park. The plots were distributed along the altitude gradient, between 150 and 750 m, and in different positions of the drainage ramps, from the river banks to the plateau regions. After the data processing carried out by Canonical Correspondence Analysis, it was identified species that are distributed in the vegetation according to the variations of altitude, humidity, fertility, saturation by aluminum and soil clay content. Some species presented tolerance to the environmental variations, a typical characteristic of species of wide geographic occurrence.