Response of Nothofagus betuloides (Mirb.) Oersted to different thinning intensities in Tierra del Fuego (Argentina).

MARTINEZ PASTUR G; CELLINI M; LENCINAS MV; VUKASOVIC R; PERI P; DONOSO S

INTERCIENCIA

Interciencia Association

Lugar: Caracas; Año: 2002 p. 679 - 685

0378-1844

Forestry in Argentina and Chile has been largely developed based on the culture of exotic species, while native species occupied a second place in the national forest policies of research and development. Nothofagus forests are the main wood resource for the sawmill industry in Tierra del Fuego. Many antecedents of intermediate treatment schedules and thinning trials have been reported, but few of them are in N. betuloides. The aim of the present work was to determine the growth and forest dynamics of a young stand, and evaluate the growth responses to three thinning levels, comparing them with an unthinned stand along six years. The 46 year old unthinned stand had a DBH increment of 0.1 to 0.2cm/yr, a volumetric increment of 6.3m³/ha_yr and a natural self-thinning of 350 trees/ yr. This stand responded positively to different thinning levels. The DBH increment reached 0.52cm/yr in the high thinning intensity treatment (2000 stems/ha), diminishing in proportion when the thinning intensity decreased (0.37cm/yr and 0.31cm/yr for treatments of 3500 stems/ha and 5000 stems/ha). Less intensive thinning treatment showed the highest volume growth (13.6m³/ha_yr) as compared with the higher intensity (9.5 m³/ha_yr). From the obtained growth and the behavior of the species to intensive silvicultural treatments, Nothofagus betuloides is a species of high potentiality in order to be incorporated within a forest intensive management.