Responses of Planted Native Warm-season Grasses and Associated Vegetation to Seasonality of Fire in the Southeastern US

State and federal agencies have promoted native grass/forb plantings to increase and enhance habitat for Colinus virginianus (Northern Bobwhite). However, many plantings have resulted in dense stands of grass that do not provide suitable structure for Northern Bobwhite. Prescribed fire is an important tool for managing succession in southeastern grasslands, and previous research has suggested that the timing of prescribed burns can influence plant community composition and structure. We examined the response of planted, native warm-season grasses (NWSG) at three sites in Tennessee to the timing of annual burns conducted 2008-2011 during March, April, May, and September. The grasses included Andropogon gerardii (Big Bluestem) Sorghastrum nutans (Indiangrass). Panicum virgatum (Switchgrass). Schizachyrium scoparium (Little Bluestem), and Bouteloua curtipendula (Sideoats Grama). We monitored vegetation response once each summer during July or August). We used mixed-model ANOVAs to analyze the effect of treatment on bare ground (no plant cover), forbs desirable for Northern Bobwhite, and each NWSG species individually for each location. Although NWSG did not show strong responses to season of burn, Switchgrass cover appeared to be increased by spring burns when compared to the control plots. Forb cover was sparse (<10%) throughout the study, and four years of burning did not stimulate forbs. Therefore, in high-rainfall environments, soil disturbance may be necessary to reduce grass cover and stimulate forb cover in dense stands of planted NWSG.