The quality of the wood of young trees of pinus caribaea grown in south africa

Abstract

This paper is a summary of the reports on the tests carried out at the Forest Products Institute to evaluate the properties of the wood of 19 to 25 year old Pinus caribaea, and a closely allied species Pinus hondurensis. The former is an important species in recent afforestation in the Union. Eighty sample trees from four localities showed that the light, soft wood put on during the early stages of the life of the tree increases in weight and strength with age at a constant and phenomenally rapid rate, until at 22 years it has certain characteristics approaching those of the imported pitch pine, though lacking its durability. The trees, which were grown at a rate of slightly less than five rings per inch, were representative of a large proportion of the timber likely to be sawn in the future and the wide variation in the weight of the wood is likely to be a disadvantage. There was little sign at 23 years that the maximum weight of the wood to be put on had been reached. A mean range in weight of as much as 17 lb. between inner and outer wood was disclosed with an extreme range in all pieces of 25 lb. (from 22 to 47 lb.). Compression wood was present in all consignments and was the main cause of degrade in scantlings. It had less effect on the larger building sizes, which were the main product from the logs. While the heavy wood was difficult to work by hand, especially in nailing, the wood from the low rainfall areas, which lacked the heavy and wide summerwood zone, was much milder and more easily handled. P. caribaea was found to produce heavier and stronger wood than most other locally grown pines and, strangely enough, the lighter wood from one locality was the strongest. It is concluded that, although it is a useful species from many points of view, on the whole it is less desirable for general light structural work than Pinus patula. On account of the light branching habit of Pinus hondurensis, a high yield of first grade structural wood was obtained from it and its milder characteristics make it a more useful timber for all general work. © 1952, Taylor & Francis Group, LLC.