Submitted to: Journal of Range Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 1, 2004
Publication Date: July 1, 2004
Repository URL: http://ars.usda.gov/SP2UserFiles/Place/54340000/Publications/PatchBurning.pdf
Citation: Vermeire, L.T., Mitchell, R., Fuhlendorf, S.D., Gillen, R.L. 2004. Patch burning effects on forage utilization and grazing distribution. Journal of Range Management 57:248-252. Interpretive Summary: Large herbivores are known to be attracted to recently burned sites. Because of this attraction, fire has generally been avoided as a livestock distribution tool for fear of localized overgrazing. However, if animal use of burned patches is predictable, then fire could be used strategically to control when and where animals graze. Our objectives were to determine cattle grazing preference for burned sites relative to non-burned sites, examine whether forage utilization was affected by season of burn, determine forb response to patch burning, and describe the relationship between forage utilization and distance from burned sites. Grass utilization was 81% on burned sites compared to 18% on non-burned sites, whether plots were burned in spring or fall. Utilization decreased in a predictable manner with increasing distance from burned patches. Forbs increased only within burned patches. Patch burning can be employed as an effective, inexpensive grazing distribution tool.
Technical Abstract: Post-fire forage growth is known to be a strong attractant for large herbivores. However, fire has generally been avoided as a grazing distribution tool for fear of localized over utilization of forage resources. Our objectives were to determine cattle grazing preference for burned sites relative to non-burned sites, examine whether forage utilization was affected by season of burn, determine forb response to patch burning, and describe the relationship between forage utilization and distance from burned sites. Sixteen 4-ha plots were burned in mid-November or mid-April and left exposed to cattle grazing for the duration of the growing season. Burn treatments were blocked within pastures to allow individual herds access to fall-burned, spring-burned, and non-burned sites. Standing crop estimates for grasses, forbs, and total herbage were made in September by clipping on burned sites and at 50, 100, 200, 400, and 800 m distant from the plot's edge. Standing crop was also sampled in exclosures on burned and non-burned sites. Cattle were strongly attracted to burned sites, utilizing 81% of the grasses within burns compared to 18% outside the influence of burns. Cattle showed no preference for one burn season over the other. Grass standing crop decreased in a predictable manner with proximity to burned plots. Grass utilization ranged from 59% at 50 m to 18% at 800 m away from burns. Forbs increased 60% to 1,095 kg ha-1 on burned plots, but were unaffected by distance from burns. Patch burning can be employed as an effective, inexpensive grazing distribution tool.