Post-harvesting silvicultural treatments in canopy logging gaps: Medium-term responses of commercial tree species under tending and enrichment planting

摘要

Technical and scientific information on medium-term effects of post-logging silvicultural interventions on the recovery of harvestable growing stocks are hardly available. To mitigate uncertainties about these effects our study aimed to answer the following question: "What is the medium-term effect of post-harvest silvicultural treatments on mortality, growth, and the structure of commercial tree species in canopy logging gaps under tending and enrichment planting?" we study individuals planted and naturally regenerated in 72 logging gaps opened tree felling during reduced-impact logging among different silvicultural treatments: (1) natural regeneration tending (TNER); (2) enrichment planting in logging gaps (EP1); (3) enrichment planting in logging gaps previously cleaned of harvesting residuals (EP2). Mortality increased through time, EP1 presented the highest mortality rates of all treatments in the first, sixth and 11th year, TNER had the lowest at the same period. TNER and EP2 presented the highest basal area and EP2 the highest periodic annual increment. Effects of the silvicultural treatment TNER were positive, since it presented the highest survival and a high mean basal area of the initial trees. The medium-term effects of silvicultural treatments applied over individuals of commercial trees in logging gaps indicate higher survival and growth that reflected in the structure of treated individuals when compared to standard procedures of reduced impact-logging, these results bring positive outcomes to reach more sustainable future cutting cycles in the Brazilian Amazon and other tropical forests worldwide.