TECHNOLOGICAL CHARACTERIZATION OF THE WOOD OF Juniperus flaccida VAR. POBLANA MARTÍNEZ

Abstract

This study was conducted in order to determine the characteristics and technological properties of the wood of Juniperus flaccida var. poblana Martínez, for which the methodology of the Forestry Department’s Wood Anatomy and Technology Laboratory at the Universidad Autónoma Chapingo was used. The physical properties were determined according to the NOM-EE-167-83 standard and the mechanical ones according to ASTM standards 143-83 at the San Martinito Research Station, operated by the Instituto de Investigaciones Forestales, Agrícolas y Pecuarias (Forest, Agricultural and Livestock Research Institute, known by the acronym INIFAP in Mexico). The results in relation to anatomical characteristics were as follows: the wood is light brown in the heartwood and pale yellow in the sapwood, and it has medium brightness, smooth figure, fine texture, straight grain, characteristic taste and aromatic smell. The tracheids are long, with medium tangential diameter and thin walls; they have a row of seriate bordered pits, the cross-field pits are of the cupressoid type and the axial parenchyma is scanty. The uniseriate-type rays are numerous, very low and very thin; the rays and axial parenchyma cells have oil. The proportion of elements was: 92 % tracheids, 7.72 % ray parenchyma, and 0.18 % axial parenchyma. The specific gravity was 0.50 g·cm-3, and the total shrinkage values were: 8.42 % volumetric, 4.26 % tangential and 3.02 % radial. The total swelling values were: 9.17 % volumetric, 4.45 % tangential and 3.12 % radial. The fiber saturation point was 33 %, the swelling coefficient 0.278 % and the anisotropy ratio 1.41. The average strength values at 12 % moisture content (MC) and in green condition were obtained for static bending, compression parallel and perpendicular to grain, hardness, shear, splitting, perpendicular to the fiber tension and impact bending. All these values were classified from medium to low in both moisture content conditions. Considering the anatomical characteristics and values of physical and mechanical properties, this wood can be used for non-structural elements such as moldings, stair treads, handrails, trimmings, furniture, racks, light-duty tool handles and crafts.