Diversity and similarity of species of natural regeneration after logging in commercially managed forest in central amazon

Abstract

This study aimed to evaluate the medium-term impacts of forest management on natural regeneration in central Amazon forest. The study was conducted in the logged forest belonging to Mil MadeirasPreciosas (Amazonas, Brazil). It was used data from continuous inventories that were carried out in 41 permanent parcels distributed in three Annual Production Units (APU), named APU B, C and D, logged in 1996, 1997 and 1998, respectively. In all units, forest inventories were carried out before logging and in the years 2001 and 2014; for APU B there was an additional inventory in 1998. The sample included trees with diameter at breast height between 5 cm and 14.9 cm. The species diversity analysis was performed by Shannon (H') and Pielou (J) indexes and the similarity analysis by Jaccard index and cluster analysis. The analyzes were made for all grouped species and commercial species group. A total of 8,090 trees families were sampled, distributed in 244 species and 48 families. Shannon index ranged from 3.77 to 4.08; Pielou index ranged from 0.74 to 0.84. There was a significant difference between H' for all species in two APUs 16 and 18 years after logging. There was significant difference between H' for commercial species before and 16 and 18 years after logging. Jaccard indexes ranged from 66.7% to 100%. The largest differences for the species composition were observed between pre-exploration inventories and the last measurement. Diversity and composition of species in the natural regeneration in the logged forest changed in a period by 16, 17 and 18 years after logging.