Second-year growth and bole quality response of residual poletimber trees following thinning in an even-aged bottomland hardwood sawtimber standThis article is part of a larger document. View the larger document here.
Poletimber trees were classified as either superior or inferior poletimber stock, and then retained on separate plots receiving identical thinning treatments. Differences in post-treatment response were used to evaluate the potential of the two poletimber classes to produce grade sawtimber in the thinned sawtimber stand. Treatments included: an unthinned control, two levels of the Desirable treatment (retained preferred and desirable sawtimber and either superior or inferior poletimber), and two levels of the Acceptable treatment (retained preferred, desirable, and acceptable sawtimber and either superior or inferior poletimber). Thinning increased the likelihood that poletimber trees we initially classified as superior will yield sawlogs in the thinned sawtimber stand. Sawtimber production from inferior poletimber seems unlikely. The Desirable treatment yielded the greatest 2 year cumulative diameter growth response by superior poletimber trees (0.49 inches), but also adversely affected the bole quality of these potentially more valuable stems (10.1 new epicormics). The Acceptable treatment yielded significant diameter growth by superior poletimber trees as well (0.31 inches), and reduced epicormic branching by nearly 60 percent of that observed in the Desirable treatment during the 2-year period. Superior red oak poletimber trees in the Acceptable treatment grew at a rate equivalent to 2 inches per decade while averaging fewer than five defect-causing epicormic branches after the first 2 years. Our preliminary conclusions are that the Acceptable treatment may provide the best combination of growth and maintenance of bole quality for growing high quality sawtimber from poletimber, particularly from the potentially more valuable red oak poletimber trees.