Amostragens longitudinais alternativas para a determinação da densidade básica em clones de eucalyptus sp.

Abstract

The purposes of this research were: a) to determine the longitudinal variation standard of basic density; b) to evaluate the main longitudinal sampling methods and; c) to propose new alternatives of representative longitudinal sampling of the average basic density. Disks were obtained from the tree basis, in the 1.30 m (DBH) position, and at every meter from this point until commercial height. Explanatory linear models of basic density longitudinal variation were adjusted. The polynomial model of fifth order was the one that better explained the longitudinal variation of basic density. This model was used for the prediction of basic density at relative heights from 1 to 100% of the commercial height. The position at 79% of the commercial height was the most precise among the ones evaluated. The sampling alternatives A (5, 25, 27, 78 and 79%), B (5, 26, 27, 78 and 79%) and C (5, 26, 27, 78 and 80%) were more adequate to the samplings commonly used.