Prescribed Burning under Differing Forest Cover Types and Its Influence on Soil Water Infiltration Rates and Physical Properties in East Texas Forests

Abstract

Little is known regarding the effects of prescribed burning on soil water infiltration and soil physical properties in Western Gulf Coast forests dominated by longleaf pine (Pinus palustris), shortleaf pine (P. echinata), or loblolly pine (P. taeda). Soil water infiltration rates were measured pre-burn (before the fire), post-burn (one month after the fire), and at green-up (three months after the fire) in areas utilizing prescribed fire with different rotations and seasons. The National Forests and Grasslands of Texas predominantly perform dormant season burns every two to three years, while the Winston 8 Land and Cattle Ltd. Tree Farm often burned biannually during the dormant season, but occasionally during the growing season. Soil samples were also collected to determine the effects of prescribed burning on soil pH, bulk density, particle density, pore space, soil strength, O-horizon weight and depth (organic matter), and water-stable aggregates. There was a significant increase in soil water infiltration rates between pre-burn and post-burn and pre-burn and green-up, and between the two different burn intervals. Soil strength initially decreased slightly, but then increased over time. Soil-stable aggregates increased significantly over time, and soil physical properties that significantly changed included soil bulk density, pore space, water-stable soil aggregates, and soil strength. This study found there could be short-term (2–3 years) responses on soil physical properties and soil water infiltration rates from repeated burning treatments, regardless of overstory species.