Seasonal Biennial Burning and Woody Plant Control Influence Native Vegetation in Loblolly Pine Stands

Abstract

This paper documents the results of a study to determine the effects of selectedvegetation-management treatments in loblolly pine. Vegetation in precommercially thinned, 6-year-old stands was subjected to five biennial growing season burns in either early March, May, or July coupled with hand felling of residual woody stems. Using a randomized complete block design, we compared the vegetation-management treatments to an unthinned, unburned, and unweeded check. By stand age 17, intensive vegetation management increased pine diameter growth by 2 centimeters (a = .004)and volume growth by 0.04 cubic meters(m³)per tree (a = .02) when compared to the check. However, this was a small biological gain in growth. Among the burned treatments, five burns in early March reduced average pine total height by 0.8 m(a = .004). diameter at breast height by 1.5 cm (a = .03), and volume per tree by 0.04 m³ (a = .06) compared to burning in early May or July. Vegetation management significantly reduced the height of hardwood trees and shrubs (a = .0001),but the number of trees and shrubs per hectare was not significantly affected. Vegetation management significantly increased total herbaceous plant production (a = .003). Pinehill bluestemwas not on the check plots, but it was the most productive herbaceous species on the vegetation-management treatments, composing 49 percent of the average total annual production of 457 kilograms per hectare.

Citation

Haywood, James D.; Martin, Alton, Jr.; Pearson, Henry A.; Grelen, Harold E. 1998. Seasonal Biennial Burning and Woody Plant Control Influence Native Vegetation in Loblolly Pine Stands. Res. Pap. SRS-14.Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. 8p.