ANÁLISES DENDROCRONOLÓGICAS DE TRÊS ESPÉCIES COMERCIAIS NO SUL DA AMAZÔNIA BRASILEIRA COMO FERRAMENTA PARA O MANEJO FLORESTAL

Abstract

The Amazon region concentrates the largest tropical ecosystem and tropical forest in the world, with hydrological and biogeochemical functions of major importance to the world. Forestry is considered one of the main economic sources of the region. However, much of this activity is still carried out in a predatory manner, causing serious damage to the ecosystem and its functions. Forest management becomes the best alternative to guarantee the sustainability and conservation of these resources. Despite all the efforts of governments to regulate laws and techniques, the great biodiversity of the forest, coupled with the few available studies, make the definition of criteria quite complex. The current forest management of native forests is governed by laws and regulations that define, as technical procedures, unique management criteria for all species. This may lead to pressure or low utilization of available resources and may cause degradation of populations of many tree species. The objective of this study was to analyze the growth rhythm and to estimate specific management criteria for three commercial tree species with natural occurrence in southern Amazon, thus contributing to the conservation and management of the timber resources of these species. In this way, traditional dendrochronological studies were carried out, applying the GOL (Growth-Oriented Logging) methodology. By the growth rings of Astronium lecointei Ducke, Clarisia racemosa Ruíz & Pavón and Hymenaea courbaril L. we were able to reconstruct the growth trajectories and evaluate the canopy reach strategies of these species as well as to model species growth, establishing criteria management, such as felling cycles - FC and minimum logging diameter - MDL, and finally, to discuss approaching current forest laws. Each species presented specifics in the growth with evident intraspecific variation that reflected in management criteria divergent from those foreseen by the actual forest legislation. These results endorse the need for a reformulation and updating of the laws and norms that prescribe technical parameters of the forest management plans developed in the Brazilian Amazon.