Short-Term Vegetation Responses to Fire in the Upper Sonoran Desert

Abstract

Annual and perennial plant vegetation was sampled following a controlled burn (1981) and a wildfire (1980) in the Upper Sonoran Desert near Phoenix, Ariz. Perennial plant composition 1 year after controlled burning included 32% shoot survivors, 30% sprouters, and 38% seeders, mostly brittle bush (Encelia farinosa1). Several invader species, stickweed (Stephanomeria exigua) and four o'clock (Mirabilis bigelovii) were important seeders, indicating that there may be postfire successional communities in the Upper Sonoran Desert. Most cacti were fire killed or died eventually from fire damage. Total annual plant density decreased (69%) while biomass increased significantly (131%) on burned areas. Red brome (Bromus rubens) was essentially eliminated 1 year after fire while schismus (Schismus arabicus) and Indian wheat (Plantago spp.) increased in both density and biomass. Fire appears to enhance rangeland productivity in the Upper Sonoran Desert.