The wood quality of Pinus chiapensis (Mart.) Andresen grown in the Mpumalanga forest region: scientific paper

  • FS Malan


The ten best performing families selected in a Pinus chiapensis trial at Tweefontein forest near Sabie have been evaluated for wood and saw timber properties. The wood was found to be soft, remarkably uniform both within and between annual rings, stable, with a well-defined heartwood zone. The latewood proportion of the annual rings was extremely small, resulting in a poorly defined ring structure.

The fifty trees studied had an average air-dry density of 0,420 g / cm3 (extracted and at 12 % moisture content) with individual tree densities varying from 0,380 to 0,465 g / cm3 at 0,8 m height level. Differences between families were highly significant, suggesting that there is a strong potential to increase the density of the wood through tree breeding.

Knots were relatively small and well shaped, and normally occurred in small clusters. Knot occlusions following pruning were accompanied by little grain distortion. When present, the amounts of included resin, pieces of bark and other debris at the occluded pruning cuts, were small and of little practical significance.

The wood machined without any difficulty in the wet and dry condition. Boards dried without any significant drying degrade, but moisture loss during drying from the heartwood zone was markedly slower compared to what is normally experienced with the pith zone of other South African commercial pines.

Some sawn pieces may not be suitable for some structural purposes where strength is important, while tests on Colombian and Brazilian grown P. chiapensis have shown that the species may not be acceptable for pulp production because of low pulp yields and high alkali consumption. Owing to its high degree of uniformity it might be well suited for special products such as for internal construction purposes, panelling and other decorative work, woodcarving and some applications in the furniture manufacturing industry. It might also be suitable for the manufacturing of items such as match sticks, toothpicks, clothes-pegs and other small wooden objects.

Southern African Forestry Journal No.192 2001: 51-58

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eISSN: 2070-2639
print ISSN: 2070-2620