Response of false broomweed and associated herbaceous species to fire

Abstract

Foliar cover of the shrub false broomweed (Ericameria austrotexana M.C. Johnston) was reduced 45 to 65% at the end of the first post-burn growing season and by an average of 29% at 4 years after controlled burning in August. False broomweed's response to February burns was more variable, ranging from 36 to 77% canopy reduction after the first growing season and 3 to 54% after 4 years. Burning in August or February temporarily decreased standing crop of the most common bunchgrasses, pink pappusgrass (Pappophorum bicolor Fourn.) and whiplash pappusgrass (P. mucronulatum Nees.), without influencing frequency of occurrence, indicating that fire reduced vigor of these grasses. Total end-of-season standing crop reflected reductions in pappusgrass production. Fire tended to favor or had no effect on other bunchgrasses, and generally suppressed frequency and standing crop of undesirable grasses such as red grama (Bouteloua trifida Thurb.). Burning in either season had little effect on common curlymesquite [Hilaria berlangeri (Steud.) Nash].