Radial and axial variation in ring width of Caribbean pine (Pinus caribaea Morelet) in Afaka Plantation, Kaduna State, Nigeria

Abstract

This paper examines the within tree variation (radial and axial) in Ring Width of Caribbean Pine (Pinus caribaea Morelet) Plantation Grown in Afaka plantation, Kaduna State, Nigeria. Samples of wood used in this study were obtained from different age series of P. caribaea. Fifteen trees were randomly harvested with their total tree height and diameter at breast height (DBH) measured. Discs of 5 cm in thickness were obtained at breast height. Additional bolts of 20 cm for pulping materials were obtained at the base, middle and top of trees sampled among the age series. Each disc was cut at the pith, smoothened and the numbers of rings were counted. Each disc was then divided into sections based on the ring numbers and the ring width were measured and recorded. The result showed that there was radial variation in the ring widths where the rings closest to the pith had the highest mean value of 8.4580±0.24608 mm, 8.3920±0.32679 mm, 6.5560±0.14006 mm at Diameter at Breast Height (DBH), 25% Total Height of Tree (THT) and 50% THT, respectively while the ring width decreases from pith to bark with rings closest to the bark having a mean value of 1.0580±0.10514 mm, 1.0100±0.09187 mm, 1.1940±0.13743 mm at DBH, 25% THT and 50% THT respectively which are significantly different (p < 0.05). Axially, there is no variation in the ring width of the growth rings (p > 0.05).

Keywords: Silviculture, dendrochronology, growth rate, wood property, wood quality