tailieunhanh - Báo cáo khoa học: " Compaction and soil disturbances from logging in Southern Chile"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài:" Compaction and soil disturbances from logging in Southern Chile. | Ann Sci For 1991 48 63-71 Elsevier INRA 63 Original article Compaction and soil disturbances from logging in Southern Chile J Gayoso A Iroumé Institute de Manejo Forestal Universidad Austral de Chile Casilla 853 Valdivia Chile Received 2 July 1990 accepted le 13 november 1990 Summary In an andesitic dystrochrept clay forest soil the effect of a different number of passes of a rubber-tyred skidder on bulk density total porosity and saturated hydraulic conductivity was studied. Soil samples were taken in undisturbed areas and under skid trails with 1 2 3 5 and 10 machine passes. Most compaction occurred after the initial few passes but bulk density also increased significantly after more than 3 passes Increases in bulk density were still important at the maximum sampling depth of 20 cm. Total porosity decreased for all treatments associated with a reduction of macropores. The saturated hydraulic conductivity became significantly reduced after the first initial passes. The effect of compaction on tree growth needs to be further studied and quantified. soil compaction I soil disturbances I ground-based logging bulk density saturated hydraulic conductivity Résumé Compactage et perturbation du sol après une exploitation forestiere au Chili meridional. On a étudié influence du nombre de passages d un débusqueur à pneus sur la densité ap-parente la porosité totale et le coefficient de conductivite hydraulique d un sol brun andésitique. Des échantillons de sol ont été prélevés dans des terrains non perturbes et sous des chemins de débar-dage ayant 1 2 3 5 et 10 passages. Le compactage le plus important s est produit après les premiers passages mais la densité apparente a encore augmenté significativement après le troisième passage. La densité apparente a aussi augmenté jusqu a 20 cm de profondeur. La porosité totale a été réduite dans tous les cas associée à une reduction des macropores. Le coefficient de conducti-vité hydraulique a été significativement réduit après les .