Variation in the density and morphology of the wood fiber of 26 clonal lines of Eucalyptus urophylla in Southeastern Mexico
摘要
Eucalyptus urophylla is widely used in forestry plantations in Mexico. However, its utilization could be optimized if the anatomical characteristics of its wood were better understood. The objective of this research was to evaluate the suitability of its wood for the manufacture of medium-density fiberboard (MDF), sawmilling industry, making pulp for paper, and producing charcoal. Seventy-eight trees of 26 clonal lines were analyzed, measuring diameter at breast height, total height, basic wood density, and fiber morphology (length, diameter, lumen width, and cell wall thickness) in the pith and sapwood at four tree heights. From these variables, indices were calculated to evaluate wood quality. Basic wood density ranged from 435 to 511 kg m⁻3 among clonal lines, with higher values in sapwood (440–542 kg m⁻3) than in pith. Fibers were short, with lengths of 955–1190 µm, diameters of 17.0–20.7 µm, lumen widths of 8.6 to 11.6 µm, and cell wall thicknesses of 3.9–5.0 µm. Wood quality indices showed flexibility coefficients of 51–57%, cell wall fractions of 43–49%, and Runkel ratios between 0.8 and 1.0. Non-metric multidimensional scaling (NMDS) and cluster analyses grouped the clonal lines into three groups differentiated by rapid growth, greater cell wall thickness, Runkel ratio, shape factor, higher flexibility coefficient, and fiber lumen width. These results highlight the potential of the studied E. urophylla genotypes for applications in the MDF industry, sawmilling, pulp for paper, as well as charcoal production.