Florística, dinâmica e estrutura da regeneração natural em floresta explorada na flona do Tapajós-Pa

Abstract

Largest area of tropical forest continues in the world, rich and highly diverse biome in plant and animal species, environment full of complex environmental relations and fragile balance, mosaic with varied topographical features and land use, synonymous with what might be called Amazon. From disparities, forest management has emerged as an alternative to the better use of forest resources, and thus the natural regeneration is one of the main mechanisms for maintaining the natural ecosystem and target planning for the future use of the forest, this being considering the current forest legislation. Thus, this study aimed to characterize the floristic composition, dynamics and structure of natural regeneration in a forest area explored in the TNF after 31 years of intervention. Natural regeneration was divided into three size classes and C1, C2 and C3, comprising individuals from 30 cm to 9.9 cm DBH. Being located the margins of BR-163 highway at km 67, Belterra municipality in the state of Pará, the study was based on the use of permanent plots of Embrapa Amazônia Oriental, where they were implements in 1981 (harvested area) and the witness in 2008, the two areas a total of 54 plots being arranged randomly and systematically. From 14.48 ha-1 effective sampling, found 14,628 plants divided into three size classes, these divided into 62 families and 370 species identified botany. The most abundant families were Fabaceae, Lauraceae and Sapotaceae, ordinary families in tropical forests, and at genus richest were Pouteria, Ocotea and Inga. For the structure, the category C3 species of greater VI were Protium apiculatum Swart (3.83%) and Virola michellii Heckel (3.83%), while for C2 were Rinorea guianensis Aubl. (6.31%) and Amphirrhox longifolia (A.St. Hil.) Spreng (5.90%). For Class C3 community mortality behaved with elevation and finally decreased their rates over the 31 years, for this flow C2 acabaou being characterized by several peaks. Assessing the populations of levelsignificance 0.05 C3 class does not havesignificant difference between treatments unlike the C2 class and the TE1 and TE2 differentthe TO.