Response of Big Bluestem (Andropogon gerardii Vitman) to Timing of Spring Burning

Abstract

-Spring burns were conducted at four day intervals from 6 April through 20 May 1988 on a reestablished tallgrass prairie in eastern Nebraska. Growth and flowering responses of big bluestem (Andropogon gerardii Vitman) were measured during October. Flowering stem height and flowering stem number increased significantly (P < 0.05) on areas burned on each of two, successive four-day intervals after 12 May. Plants on areas treated before 12 May showed no such response. The closely timed, but significantly different, responses emphasize the importance of careful attention to specific time of burning and associated plant growth status. This is particularly relevant when interpreting the effects on such broadly defined treatments as Spring burn. Further, this study suggests that there may be some activity, either environmental or physiological, that changes dramatically over as few as four days and that significantly affects big bluestem.