Diameter distributions and spatial distribution patternsof tree species are important for planning sustainablemanagement in natural forests in the eastern Amazon

Abstract

Background: Do tree species that have wood of high commercial value which are being extracted in the Saracá-Taquera National Forest have diameter and spatial distribution patterns that enable continuous production of timber to meet the criteria of ecological conservation and sustainable management of their populations? To answer this question, we evaluated diameter and spatial distributions of 15 commercial tree species of ecological and economic importance, in a concession area in the Saracá-Taquera National Forest, Eastern Amazon.

Methods: The data were obtained from a forest inventory carried out in 24 50 m × 50 m plots, considering a minimum diameter of 30 cm. The 15 species were selected based on three criteria: importance value index; volume stock; and commercial value of the wood. The trees were distributed into diameter classes with an interval of 10 cm between them to analyse the diameter distribution. The spatial distribution patterns of the species were analysed using the univariate Ripley’s K function.

Results: The results showed that the presence of large trees and the aggregated spatial distribution in most of the tree species studied may determine the feasibility of continuous timber production to meet conservation and sustainable management criteria. The spatial distributions of stocks should guide planning of forest management activities, including pre-logging, logging and post-logging activities. However, the low population density of most species suggests that logging must be well planned to avoid population declines. Although forest management on a sustainable basis has advanced substantially in recent years in the Amazon, the factors that promote different diameter and spatial distributions of species are still considered complex and little studied.

Conclusions: The results point to a need to expand research on this topic in managed areas, including the same technological approach as the work described here. This type of analysis can constitute an important tool for defining population management strategies for each species, considering their ecological characteristics and environmental adaptation at a local level.