Caracterización estructural del bosque pantanoso de mirtáceas de la región de la Araucanía, Chile

Abstract

Chile swamp forests have a wide and fragmented distribution (1 300 km approx.) and are dominated mainly by mirtaceas. They are associated with poorly drained soils, so their hydroperiods are temporary or permanent. The best-known aspect of these forests is the floristic-vegetation, although information on its structural composition is generally weak and nonexistent for the remnants of the La Araucania region. The aim of this study was to characterize both vertical and horizontal structure of swampy forests that grow in the locality of Catrimalal, Labranza, Pumalal and Quepe in the central depression of La Araucania region. In each locality a rectangular plot of 300 m2 was established, tree species present were recorded and basic dasometric parameters were measured. In order to determine differences between the studied localities an analysis of covariance (ANCOVA) and a Tukey test were carried out. The vertical structure consists of four species of trees: Blepharocalyx cruckshanksii (Hook. & Arn.) Nied, Drimys winteri J.R. Forst. & G. Forst., Luma chequen (Molina) A. Gray and Myrceugenia exsucca (DC.) O. Berg, whose general average of height and diameter at breast height (DBH) reach 11.8 m and 22.1 cm. respectively. The horizontal structure shows an average canopy cover of 87% and D. winteri as the species with the highest coverage of crown. Statistical analyzes indicate the presence of significant differences among localities, mainly in Quepe. Low average levels of canopy coverage and height compared to previous descriptions could suggest a human impact on these forests. The difference found in Quepe could be due to a shorter hydroperiod, since this phenomenon regulates among others, the structure of these ecosystems. Swamp forests are essential for the maintenance of groundwater, therefore actions for their protection and conservation are increasingly necessary.