Longleaf and Slash Pine Decreases Herbage Production and Alters Herbage Composition

Abstract

An overstory or slash pine on the Palustris Experimental Forest in central Louisiana decreased herbage production as early as plantation age 17 for longleaf pine and plantation age 10 for slash pine. During the years of 1960 through 1975, from 80 to 85% of the variation in herbage production could be explained by the equations, Y = 2094.75 + 10.10P - 106.98BA for longleaf pine and Y = 1606.18 = 14.03P - 88.10BA for slash pine, in which Y = herbage production in kg/ha, P = April through October precipitation in cm, and BA = pine basal area in m2/ha. Pinehill and slender bluestem were the principal herbaceous species on nonforested plots in 1975, while a mixture of forbs, pinehill bluestem, and other bluestem grasses were most common on forested plots. The study quantifies data on herbage production and botanical composition over time and suggests ways for the forest manager to evaluate timber and herbage tradeoffs.