The effects of silvicultural treatments on the chemical composition of plantation-grown loblolly pine wood

Abstract

The influence of silvicultural treatments (fertilization, stand density, and pruning) on the chemical composition (hot-water extractives, alcohol-benzene extractives, ether extractives, Klason lignin, holocellulose, and alpha-cellulose) of outerwood and innerwood of plantation-grown 12-year-old loblolly pine (Pinus taeda L.) was investigated. Plots located near Bogalusa, in southeastern Louisiana, were maintained at four levels of stand density (2,470; 1,976; 1,482; and 988 trees per hectare) and exhibited varied effects on wood chemical properties. The highest mean extractive contents occurred in the plots with 2,470 residual trees per hectare. Stand densities did not appear to be consistently related to Klason lignin, holocellulose, and alpha-cellulose contents. Fertilization caused a significant reduction in alcohol-benzene extractive content, ether extractive content, and Klason lignin. There was no significant effect in any chemical property attributable to the pruning treatment, except in alcohol-benzene extractives, which decreased significantly in the pruned trees. Innerwood yielded significantly greater extractive contents for the alcohol-benzene and hot-water methods of extractive content determination, and outerwood yielded significantly higher values for Klason lignin, holocellulose, and alpha-cellulose.