Response of understory vegetation important to the northern bobwhite following imazapyr and mechanical treatments

In southern pine (Pinus spp.) stands, managers have used a variety of treatments to control hardwood encroachment and improve habitat conditions for northern bobwhites (Colinus virginianus). We compared use of the herbicide Arsenal® (BASF Corporation, Research Triangle Park, N.C.) (imazapyr) and traditional mechanical treatments, with and without fire, to control hardwood encroachment on study sites on Tall Timbers Research Station in the Red Hills Region near Tallahassee, Florida. Hardwood stem density decreased on herbicide and herbicide+burn plots but increased on all mechanically treated plots at 1 year after treatment. Herbicide and herbicide+burn treatments resulted in a >3-fold increase in forb coverage 1 year after treatment, whereas forb coverage did not increase in mechanically treated plots. A single application of imazapyr, with or without prescribed fire, can control hardwood encroachment and stimulate herbaceous species growth. Following treatment, vegetative communities likely can be maintained for prolonged periods by using traditional methods such as prescribed fire.