Responses of Understory Vegetation on Highly Erosive Louisiana Soils to Prescribed Burning in May

Prescribed burning is necessary to restore the herbaceous plant community normally associated with the fire-dependent longleaf pine, Pinus palustris Mill., ecosystem. Usually these burns are done in the winter months. However, burning during the early growing season may allow herbaceous plants to recover better than when burning is conducted during the winter months. It was hoped that the additional herbaceous growth would decrease soil movement, a problem on highly erodible hilltop glades of Kisatchie soil (Typic Hapludalfs). The effects of a May burn on soil movement and vegetation growing on two hilltop glades were monitored through one growing season. A prescribed burn on May 24,1994, reduced vegetation and litter cover on the soil surface and the number of woody plants in the understory. This treatment also adversely affected the richness of woody plants within the herbaceous layer and initially reduced the herbaceous standing crop compared to preburn conditions. Soil movement doubled after the May burn; but in another study, a November burn had a similar effect on soil losses. Because the May burn adversely affected woody plants while maintaining the herbaceous plant community, this treatment may be preferable to winter burning on steep, highly erodible Kisatchie soils.