Development of native and exotic woody species in the Patagonian cypress forests.

Abstract

Development of native and exotic woody species in the Patagonian cypress forests. The growth and architecture of forest-dwelling woody plants affect the dynamics of these communities. The present study was aimed at improving our understanding of the dynamics of Argentinean Austrocedrus chilensis forests through the study of length growth and architecture of some of the most frequent native and exotic woody species in these communities (natives: Aristotelia chilensis, Berberis microphylla, Lomatia hirsuta, Maytenus boaria, Myoschilos oblongum and Schinus patagonicus; exotics: Juniperus communis, Prunus avium, Pseudotsuga menziesii and Rosa rubiginosa). During the study period (20122014), the length growth of the main axis was not necessarily related to the height growth of labeled plants. Reductions in height were found for individuals of all species but P. menziesii and P. avium, which are exotics in Patagonia. The majority of plants presented notable deviations of the main axis from the vertical; the extent of this deviation was negatively correlated with both the length of the distal main-axis shoot and the height variation of the plant. The species under survey may be categorized in four functional groups according to their architecture. The invasion of these cypress forests by exotic species such as P. menziesii y P. avium, which belong to functional groups different from those of the most frequent coexisting native species, may promote the competitive replacement of native species by exotic species.