ABSTRACT

The African mahogany (Khaya senegalensis) in homogenous plantations and natural forests is widely studied, but there is a lack of information on wood from trees grown in agroforestry systems (AFSs). The objective of this work was to evaluate the wood quality of African mahogany produced in AFS. The wood was obtained from a multi-stratified AFS located in the State of Rondônia, Brazil. The contents of holocellulose (67.2%) and lignin (25.8%) of mahogany wood are comparable to those found in other tropical woods from the Amazon with high natural durability. The results found for the densities presented low variation, allowing to classify the African mahogany wood as of medium density (basic density around 520 kg m⁻³) and high dimensional stability (ie, anisotropy coefficient <1.3%). The results obtained for parallel-to-grain compression strength (26.5 MPa), static bending strength (56.0 MPa), shear strength (10.4 MPa), and Janka hardness parallel to the grain (3420.0 N), indicate that the mechanical performance was similar to wood from other African and South American mahogany species from monocultures and natural forests. Experimental results indicated that the wood produced in the AFS can be suitable for furniture, musical instruments, applications in external structures, residential floors, and vehicle bodies.

摘要

对均质种植园和天然林中的非洲桃花心木 ( Khaya senegalensis ) 进行了广泛研究，但缺乏关于混农林业系统 (AFS) 中种植的树木的木材信息。这项工作的目的是评估 AFS 生产的非洲桃花心木的木材质量。木材是从位于巴西朗多尼亚州的多层 AFS 获得的。红木的全纤维素 (67.2%) 和木质素 (25.8%) 的含量可与来自亚马逊的其他热带木材相媲美，具有很高的天然耐久性。发现的密度结果呈现低变化，允许将非洲桃花心木归类为中等密度（基本密度约为 520 kg m ^-3)和高尺寸稳定性(即各向异性系数<1.3%)。平行于纹理的压缩强度 (26.5 MPa)、静态弯曲强度 (56.0 MPa)、剪切强度 (10.4 MPa) 和平行于纹理的 Janka 硬度 (3420.0 N) 获得的结果表明，机械性能相似从单一栽培和天然森林中的其他非洲和南美桃花心木树种中提取木材。实验结果表明，AFS 生产的木材适用于家具、乐器、外部结构、住宅地板和车身的应用。