Forage Response to Overstory Reduction on Loblolly-Shortleaf Pine-Hardwood Forest Range

Abstract

Herbage and browse production after selectively cutting unevenaged stands of loblolly-shortleaf pine to various densities were generally related to residual pine basal area and site quality. Exceptions were at least partially the result of shrub and hardwood crown cover development on the triennially burned range. Uniolas were the principal forage species under stands having high residual pine basal area, bluestems were the major forage component on clearings. Browse made up about one-fourth of the forage under stands having high residual pine basal area but represented considerably lower proportions on clearings. Loblolly pine (Pinus taeda) and shortleaf pine (P. echinata) are the dominant trees in the most extensive forest type in the South. Although timber production is the principal use of these forests, they also provide valuable habitat for white-tailed deer (Odocoileus virginianus) and are grazed extensively by cattle. Management techniques for maintaining or improving the forage resource need refinement, however. This paper reports a study to determine the relation of quantity and composition of understory vegetation to a wide range of overstory densities. The study, begun in 1969, was carried out in uneven-aged stands subjected to a 3-year rotational winter burn. Study Area Three forest blocks at elevations between 42.6 and 48.8 m above sea level in north-central Louisiana were studied. Blocks were 1.6 to 2.2 km apart, and topography within blocks was nearly level. Before cutting treatment, loblolly-shortleaf pine basal area averaged 25.79 m*/ ha. Pines ranged in size up to 71.12 cm dbh. Pine 2.54 cm dbh or larger averaged 278/ha, and pine seedlings were abundant. Loblolly was the dominant pine, having an average site index of 29.88 m at age 50, and a site index range of from 25.50 to 33.54 m. Shortleaf pine site index averaged 26.22 m. The average age of pines was about 50 to 60 years. Differences in tree site quality and corresponding differences in soil series and A-horizon depth were apparent on the study area. Site indices less than 27.50 m included soil series Susquehanna and Keithville, with less than 15.24 cm A-horizon depths; indices more than 29.00 m included series Susquehanna,

Understory Plant Response to Site Preparation and Fertilization of Loblolly and Shortleaf Pine Forests

“…Similar findings were reported in Georgia by Halls et al (1956). Wolters et al (1982) theorized that shrub and hardwood crown cover could influence herbaceous plant production equally or to a greater extent than pine basal area or site quality. Shrubs and hardwood trees sprout prolifically after thinning the overstory or burning and soon appear to limit herbaceous production.…”

Forest overstory-understory relationships in Alabama forests

“…Errors identified by the software have been corrected; however, some errors may remain. Gaines et al, 1954;Pearson and Whitaker, 1974;Wolters and Schmidtling, 1975;Meyers, 1977;Grelen and Lohrey, 1978;Clary, 1979;Wolters, 1982;Wolters et al, 1982 ). The ability of these models to predict understory vegetation for other similar areas has not been examined.…”

Plant Response to Soils, Site Preparation, and Initial Pine Planting Density

“…Pulpwood or early sawlog production can usually be rapidly achieved through wider initial tree spacings or early thinnings (Burton 1982). Also, low tree densities result in more forage (Wolters et al 1982). Timber harvesting, site preparation, and reforestation aspects all can affect immediate and long-term understory resources, which provide forage for livestock and habitat for wildlife.…”