Underplanting shortleaf pine in the Missouri Ozarks

Abstract

A study was established on Clearwater Conservation Area in the Missouri Ozarks in which shortleaf pine (Pinus echinata Mill.) seedlings were underplanted in mature mixed oak and oak/pine stands. Overstory trees were harvested a few months after planting, leaving different levels of residual overstory stocking. The different overstory treatments included 1) uneven-aged management with group openings; 2) clearcut; 3) shelterwood treatment with overstory reduction to B-level stocking; and 4) shelterwood treatment with overstory reduction to C-level stocking. Seven years after treatment application, clearcut stands had the best stocking and growth of planted shortleaf pine seedlings. The clearcut stands also had the highest number of free-to-grow seedlings. The higher the retained overstory stocking, the lower the number of free-to-grow shortleaf pine seedlings, and the lower the stocking and growth of underplanted shortleaf pine seedlings. Group openings established in uneven-aged management treatments appear to work, but the results suggest that they should be much larger to effectively regenerate pine. Growth of natural advance reproduction while in the understory, and released after clear cut harvesting was similar to growth of underplanted shortleaf pine seedlings and released after clearcut harvest, seven years after planting. This suggests that underplanting was effective in allowing planted pine seedlings time to become established and, therefore, capable of responding once released. Findings of this study suggest that clearcutting is the best method of regenerating pine, and that the higher the stocking rate of the residual overstory, the poorer the growth and stocking of the underplanted seedlings. The results also suggest that retaining the overstory for 7 years adversely affects stocking and growth of shortleaf pine seedlings and, thus, early release of underplanted seedlings is likely to result in a greater increase in stocking and growth.

Parent Publication

• Shortleaf pine restoration and ecology in the Ozarks: proceedings of a symposium

Citation

Jensen, Jason; Smith, Cliff; Johanson, Mark; Gwaze, David. 2007. Underplanting shortleaf pine in the Missouri Ozarks. In: Kabrick, John M.; Dey, Daniel C.; Gwaze, David, eds. Shortleaf pine restoration and ecology in the Ozarks: proceedings of a symposium; 2006 November 7-9; Springfield, MO. Gen. Tech. Rep. NRS-P-15. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station: 112-116.