Wood properties of Carapa guianensis from floodplain and upland forests in Eastern Amazonia, Brazil

Anderson Vasconcelos Firmino,Maria Naruna Felix De Almeida,Marcelino Guedes,José Cola Zanuncio,João Gabriel Missia Da Silva,João Vicente De Figueiredo Latorraca,Graziela Baptista Vidaurre,José Tarcísio Da Silva Oliveira

doi:10.1038/s41598-019-46943-w

Abstract

The variable environmental conditions of the Amazon forest can affect the wood properties of the tree species distributed across its diverse phytophysiognomies. Carapa guianensis (Andiroba) occurs in upland and floodplain forests, and the wood and oil of its seeds have multiple uses. The aim of this study was to evaluate the wood properties of C. guianensis trees in upland and estuarine floodplain forests of the Amazon River. Eight trees were selected, with four being from the upland and four from the floodplain forests. The fiber length, fiber wall thickness, vessel diameter and frequency, microfibril angle, specific gravity and wood shrinkage were evaluated. The juvenile and mature wood zones were determined according to these variables. The fiber length, fiber wall thickness and specific gravity increased, and microfibril angle decreased, in the pith to bark direction. Only the fiber length variable was efficient for delimiting juvenile, transition and mature wood. The fiber length, wall thickness and specific gravity of wood were higher in upland forest trees. However, the environment did not alter the beginning of the formation and proportion of C. guianensis mature wood. This information is important for the log fit in cutting diagrams, aiming toward improving the production, classification and processing of pieces with specific quality indexes in order to direct them to appropriate wood uses.

Highlights

The Amazon is the largest biome in Brazil, occupying almost half of the territory, and the largest world biodiversity reserve
Almost twice as many C. guianensis trees were found in occasionally flooded forests compared to dry forests[7], making it necessary to study the properties of C. guianensis wood in both environments
The fiber length, wall thickness and specific gravity values had similar trend in both forests, but with lower values in the wood from floodplain trees, while the microfibril angle was smaller in upland forest trees (Fig. 1)

Summary

Introduction

The Amazon is the largest biome in Brazil, occupying almost half of the territory, and the largest world biodiversity reserve. Mature wood, developed in the mature stage of the vascular cambium, has more uniform properties and greater mechanical resistance, with better characteristics for sawmill and structural purposes[9,10,11] Wood properties such as fiber length and wall thickness[10,12], microfibril angle[13], width of the growth ring[14], specific gravity[15] and shear modulus[16] are used to define the transition between juvenile and mature wood. The aims of this study were to evaluate the anatomical and physical wood properties, to identify changes between juvenile, transition and mature C. guianensis wood from trees in upland and flooded areas in the Amazonian region of Brazil, help management plans for this plant and its wood processing

Objectives

Methods

Results

Discussion

Conclusion