ABSTRACT
This research was carried out in an Araucaria angustifolia forest which belongs to The National Forest of São Francisco de Paula, RS state. Its purpose was to compare four sampling methods of variable areas (Strand, Prodan, Quadrant and Bitterlich) with the method of Fixed Area Plot; and to determine the efficiency of each method in the estimation of quantitative parameters (CommerciaI out bark volume, number of trees and basal area), and the qualitative ones (ocurring species) of the population. The inventory of a hectare tract of forest was done considering all the trees with a breast height circumference (CAP) 30 cm. These trees were identified and their total commercial heights were measured. The Fixed Area Method adopted was the one with strips of 100 m of length and 10 m of width (10 contiguous strips of land). For the Prodan, Quadrant and Bitterlich methods, 25 points were established systematically distributed along 20 m and in the Strand Method 30 contiguous lines of 15,7 m of length. Through analysis of variance, it was observed that these methods did not show significant differences in term of volume estimation, basal area and number of trees. A significant difference was found for the number of ocurring species, being the Fixed Area Method the one that showed the highest average, differing from the other methods. After writing down the time and finding the coefficient of variation for each estimation, the relative efficiency, the result was that the Strand Method was always superior to the others in estimation of all parameters. On the other hand, the Quadrant Method showed the lowest relative efficiency in the parameter estimation.
Key words:
Sampling Methods; Araucaria angustifolia Forest; Forest Inventory