Spacing and slash pine quality timber prodution

Abstract

Cubic volume production as related to spacing in planted slash pine (Pinus etliottii var. elliottii) is well understood. Yield increases as number of surviving trees per acre increases, although at a diminishing rate after a certain point. It is also well known that wider spacings, 200 to 400 trees per acre, are necessary for optimum sawtimber yields at 25 to 30 years of age. However, many foresters question the value of open spacings for sawtimber and veneer stock production because of the wide annual rings and the lack of self-pruning. They believe a narrow spacing is necessary to produce lumber that meets the "dense" classification. Southern Pine Inspection Bureau (SPIB) (1968) specifies that dense lumber "averages on either one end or the other not less than 6 annual rings per inch and not less than 1/3 summerwood, . . . . Pieces averaging less than 6 annual rings per inch and not less than 4 meet dense requirements if averaging 1/2 or more summerwood." \t

Citation

Bennett, Frank A. 1969. Spacing and slash pine quality timber prodution. Res. Pap. SE-53. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southeastern Forest Experiment Station. 10 p.