Regeneração natural e plantio de enriquecimento de espécies comerciais em clareiras de exploração de manejo florestal em pequena escala

Abstract

Logging in the Amazon has been growing in recent years, increasing pressure on remaining timber stocks. In order to minimize these impacts, some measures have been adopted in recent years, using low-impact management techniques. These techniques reduce impacts on the structure and dynamics of the forest, leaving a less disturbed environment after logging. This work is divided into two chapters. In the first chapter, we evaluate the potential for natural regeneration in clearings from small-scale forest management in the state of Amazonas. For this purpose, 64 clearings were selected and characterized according to the size and openness of the canopy. A total of 543 individuals were found, belonging to 68 species, divided into 16 botanical families. The families Burseraceae (53.96%), Fabaceae (10.87%) and Lecythidaceae (5.52%) were the ones with the largest number of individuals. When separated by size class, small gaps presented the highest number of species (44 species), followed by large (41 species) and medium (37 species) gaps. Species of the genus Protium dominated natural regeneration in the gaps. In chapter two, we analyzed the initial development and mortality of eight forest species inserted via enrichment planting in the 64 inventoried gaps. For this purpose, seedlings of Dipteryx odorata, Handroanthus serratifolius, Swietenia macrophylla, Bertholletia excelsa, Carapa guianensis, Hevea brasiliensis, Cariniana micrantha, and Hymenaea courbaril were planted. Sixty-four gaps were selected for planting, and 32 gaps received the release treatment. The treatment consisted of eliminating competing plants within a radius of 1 meter from the canopy projection of the planted species. The results of the analyses showed varied patterns among the species, with better performance for the species D. odorata, S. macrophyla, H. brasiliensis and C. micrantha. It is necessary to select species that are adaptable to clearing conditions to ensure good performance in planting. The results prove that natural regeneration, combined with enrichment planting with species such as D. odorata and S. macrophylla, are effective strategies for the recovery of logged areas, although some species show different responses to the interventions. This combined approach shows promise for the sustainability of forest management in the Amazon.