Avaliação da quantidade de resíduos lenhosos em área de floresta explorada e não explorada, utilizando amostragem por linha interceptadora, no médio Rio Moju, Pará, Brasil

Abstract

This dissertation compares the volumes of coarse woody debris produced in an area of primary forest with another area of forest logged using reduced impact methods called Farm Saint Marta (3º04'S, 49º14'W). This area is located in the hidrografic basin of the medium river Moju, near the city of Homonym, Northeast of the State of Pará, Eastern Amazônia. The studies were carried out in a total area of 426Ha, incorporating the 4 Work Units of forest management areas. Two of these units have been explored by reduced impact logging, totaling 217Ha, and the other two units are primary forest totaling 209Ha. Line intercept sampling was the method used to quantify the coarse woody debris in 6,000 m of lines for each unit, totaling 12,000 m of sampling lines. The fallen woody debris was measured on the forest floor, with diameter over 10 cm, considering the diameter and the state of decomposition of the measured parts, for the calculation of the volume and necromassa, as related to the indices of density of the specific wood for each decay class. Statistical tests demonstrated a significant difference in the volume and necromassa estimates, and a highly significant difference in the carbon supply, between the study sites. Studies were conducted to test the correlation between the classes and the diameters, which were adjusted to the linear regression equation, in this way demonstrating that there was a correlation between these indicators in the study sites. The correlation between diameter classes and their respective volumes was also tested, and the adjustment of this result to the linear regression equation demonstrated a correlation between these instances. This generated specific equations for the case study, for the quantification of the volume of woody debris through the diameter of these materials, measured in the forest, with the objective of generating of indicators for utilization on an industrial scale. The estimates of necromassa and carbon will contribute towards the monitoring of emissions of greenhouse gasses emitted by the coarse woody debris as well as for calculations for the commercialization of carbon credits.