Dynamics of a Forest Submitted to Logging in the Eastern Amazon, Brazil

ABSTRACT Logging is an economically important activity in the Amazon; however, there are doubts regarding its sustainability, even under planned systems. This study sought to evaluate the dynamics of the structure and composition of a forest undergoing logging operations in a Sustainable Management Unit (SMU) located in the Mamuru–Arapiuns lots of the cities of Juruti and Santarém, in the state of Pará, Brazil. The studied areas are under public concession and are closely monitored by Brazilian environmental agencies. Data were collected from permanent plots before and after logging (years 2012 to 2015). Our findings raise concerns regarding the prospects of sustainable logging because mortality rates exceeded recruitment rates, causing significant decreases in tree density per hectare and basal forest area. The diameter increment rate in the forest community was 0.82 cm year−1; crown shape and lighting significantly influenced tree diameter growth. There was initially a decrease in tree diversity followed by an increase, resulting in higher diversity levels than those observed prior to logging. There were minor changes in the composition of the forest community, with a particular shift toward pioneer species. We concluded that logging affected forest dynamics at a level that calls its prospects for sustainability into question.