Relationship of stand characteristics to quality of loblolly pine

Current management practices in the loblolly pine (Pinus taeda L.) belt usually include stand improvement measures designed to reduce the number of hardwoods in the stand to a minimum.There is a sound basis for such measures.Many of the hardwoods which are associated with the pine in this mixed forest are of lower quality and lower value than the pine.In fact, there is no market at all for some of them.A primary ob- jective in the business of forestry is the production of the greatest pos- sible volume of the most valuable species.Therefore, most of the owners and managers of the larger forest land holdings have undertaken to eli- minate the hardwoods and grow only pine.Such practices may not result in the greatest financial return from forest land because of the fact that the value, in dollars, of the timber grown on any given acre may be just as dependent upon the quality of the timber as upon the quantity.It is doubtful that second-growth stands of loblolly pine will ever produce the high quality trees which were found in the virgin forest, but there are definite possibilities of im- provement of the quality of the individual tree through the use of inten- sive silvicultural practices.Manipulations of stand composition are with- in the province of the forest manager and may be of some value in im- proving tree quality.Indiscriminant hardwood subjugation, as now embodied in most loblolly pine management recommendations, ignores the fact that stand composition may have a considerable effect upon the quality of the trees which are produced.Although the relative merits of pure and mixed stands have received considerable attention, both in this country and in Europe since the establishment of the profession of forestry, there has been little research which was designed specifically to shed light upon the relationships between the quality of loblolly pine lumber and the various factors which contribute to stand composition.Many questions remain unanswered.This report summarizes the procedures and results of a study in the Florida Parishes of Louisiana which was designed to add to the knowl- edge of the effects of stand composition upon freedom from knots in loblolly pine lumber.