Análisis del incremento de madera en plantaciones de Pinus caribaea var. hondurensis Barr et Golf en Turrialba, Costa Rica.

Abstract

The increment of Pinus caribaea var hondurensis between 9 and 12 years of age has been calculated for 10 sample plots of 0,1 ha each established within small plantations in the Valley of Turrialba, Costa Rica. The mean annual increment varied between 316 and 684 m'/ha with a bark percentage between 21 and 24 per cent. The highest increments were jound on sites with deep, well-drained soils. The plantations, spaced al 2,5 x 2,5 m close their canopy at age 6 - 7. Until this age the development of weeds, mainly grasses, in the pine plantations is very vigorous. Four out of the ten sample plots were submitted to a moderate selective thinning in which the relative spacing index (5%) was raised with values between 4 and 5,6 per cent. From the silvicultural point of view it seems necessary to carry out a first thinning when the stand closes canopy. New trials should provide data about the most appropriate moment and intensity of thinnings.