Volume Growth Loss: A Hidden Cost of Periodic Prescribed Burning in Longleaf Pine?

Abstract

Abstract The influence of understory hardwood control treatments, including periodic prescribed burning, on the growth of longleaf pine (Pinus palustris) was monitored over a 10-yr period. Treatments, established in 14-yr-old sapling stands thinned to 500 trees/ac, included biennial prescribedburns in (1) winter, (2) spring, (3) summer, and (4) an unburned check. Each of these was combined with three supplemental treatments: (1) initial chemical treatment of all hardwood stems, (2) repeated handclearing of all woody stems, and (3) no treatment. All measures of pine growth weresignificantly reduced by the burns. Pine volume growth over the first 7 years on unburned plots exceeded the average on burned plots by 23% (24 ft³/ac/ yr). During the next 3 years, volume growth on unburned plots exceeded the average on burned plots even more—by 33% (44 ft³/ac/yr).Supplemental treatments did not affect pine growth, even though plots without these treatments developed hardwood stands (>l.5-in. dbh) ranging from 4.0 ft³ basal area/ac with summer burns to 11.6 ft² on unburned plots. South. J. Appl. For. 11(3):154-157.