Variations in the longitudinal gas permeability of three [Philippines] dipterocarp species
1986
Tesoro, F.O. | Peralta, P.N. (Forest Products Research and Development Inst., College, Laguna (Philippines))
The longitudinal gas permeability of three Philippine dipterocarp species, namely, Shorea negrosensis Foxw. or red "lauan", S. palosapis (Blco.) Merr. or "Mayapis" and Parashorea malaanonan (Blco.) Merr. or "bagtikan" was studied to determine variations among species, among trees within species, and within a given tree. Permeability was also related to treatability with creosote. Measurements using purified nitrogen gas as the permeating fluid were made on dowel specimens 2.22 cm in diameter cut at different locations along the radii of the four quadrants of disks taken at different heights of a given tree. Variation in permeability among species was highly significant. With S. palosapis and P. malaanonan, variation among trees was significant but not within S. negrosensis. Permeability also significantly varied with radial location and height, but not with quadrant. Variation with height, however, was rather inconsistent. A positive relationship was also noted between the logarithm of permeability and treatability, particularly retention of creosote.
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