Effect of Reduced-impact logging on Floristics, Structure and Diametric Prognosis in the Tapajos National Forest, Pará

Abstract

The modeling of the diametric distribution through the transition matrix prognosis can be a fundamental tool to understand a future structure of a forest subjected to reduced impact exploration (EIR). The objective of the study is to make a prognosis of the diametric structure for a tropical forest with a history of EIR in Flona Tapajós, Pará. Data were collected at the Annual Production Unit (UPA) n ° 3 through an inventory of 10 permanent plots of 50 mx 50 m. 4 were transported, the first capture occurred before the exploration (2007) and the rest after (2010, 2013, 2016). An exploration took place in 2008 with a cutting intensity of 15.68 m³ / ha. For the projection, two transition matrices from the years 2007-2010 and 2010-2013 were used, which were compared with the actual diametric distribution of 2013 and 2016. Statistical evaluation of the real and projected distributions was analyzed by the Kolmogorov-Smirnov (KS) test at 1% significance. The distributions designed by the two standard J-inverted matrices. The projection of the probabilistic matrix 2007-2010 was adherent until 2013 (5 years after logging), while of the 2010-2013 matrix until 2016 (8 years after logging), recommending the latter for a prognosis of the forest structure. The transition matrix method can be used for sustainable forest management to project the density by diameter class after logging but should be cautious when carrying out for long periods.