Effect of conventional and reduced impact logging in the semi deciduous forest of Misiones, northeast of Argentine.

Abstract

The present study was developed in the Multiple Use Guarani Forest Reserve, in Misiones, Argentine. There, 15 permanent plots of four hectare each one were installed. Each plot had an effective area of one hectare measured and it was distributed in three treatments: Conventional Logging, Reduced Impact Logging and control. At the year of logging (1999) and eight years later (2006), all the trees larger than 10 cm of diameter at breast height (DBH) were measured. The logging created a total surface of gaps of 8,018.7 m², which represented 6.7% of the total sampled area, where 65% were generated by the Conventional Logging. The basal area damaged was higher in the Conventional Logging treatment (70% of the total). The Reduced Impact Logging concentrates the gaps on classes of lower sizes and in smaller average areas. The number of damaged individuals was 13.6 stems.ha^-1, with a higher percentage of damages caused by the Conventional Logging. The cut of individuals was the main cause of damage and the crown was the most damaged part of the tree. A positive and significant relation was determined between the logging basal area and the damaged basal area (R² = 0.49). The planning of the logging showed to be the main factor in the reduction of the hold over stem damages. Beyond that, the slaughter directing the tree fall showed to be one of the techniques that reduce damages.