Natural and preservative-treated durability of Populus nigra cv Italica timber grown in Santa Cruz Province, Argentina

Populus nigra cv Italica (Alamo criollo) is the main species planted for windbreaks in Santa Cruz Province (Argentina). Alamo has been a traditional source of poles for rural constructions in southern Patagonia. The objective of this work was to evaluate the natural and CCA-treated durability of P. nigra cv Italica cultivated in different sites of Santa Cruz. Laboratory decay tests were carried out using the modified ASTM Standards D-1413 (1976) and the López and Deschamps (1978) technique, with two fungal species: white rot Trametes versicolor and brown rot Lentinus lepideus. Lenga (Nothofagus pumilio) heartwood, a widely used native timber in the region, was also included in the study as a control. Physical and anatomical analyses were carried out. Although important differences were found in anatomical and physical properties of Alamo timbers between sites of, no significant differences were found in relative weight loss over 50 and 150 days, for either fungal species. Natural Alamo timber had the greatest weight loss over 150 days (66.8% for T. versicolor and 29.8% for L. lepideus). CCA treatment improved the Alamo wood durability compared with Lenga heartwood (1.1% versus 29.2% weight loss with T. versicolor and 2.5% versus 13.6% for L. lepideus, respectively).