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Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Abstract Only Publication Acceptance Date: 10/1/2009 Publication Date: 2/22/2010 Citation: Augustine, D.J., Derner, J.D. 2009. Interactive Effects of Fire and Grazing in Shortgrass Steppe. In: Proceedings of the Society of Range Management and Weed Science Society of America joint annual meeting, "Working landscapes, providing for the future." Abstract PC-92. p. 92. Interpretive Summary: Technical Abstract: Combined fire and grazing management has been recommended as a tool to generate a heterogeneous vegetation mosaic and achieve conservation objectives in tallgrass prairie of the eastern Great Plains. Less is known about fire-grazing interactions in semi-arid grasslands of the western Great Plains. We initiated a patch burning experiment in shortgrass steppe (northeastern Colorado) comparing 3 unburned pastures with 3 pastures in which 25% of the area is burned per year. The first burns in November of 2007 were conducted with a mean fuel load of 698 kg ha-1 and produced maximum temperatures of 102 – 221°C at 1 – 2 cm aboveground. Initial findings show herbaceous plant production on burns (mean + 1SE = 498 + 82 kg ha-1) was similar to unburned sites (462 + 53 ka ha-1; P = 0.73) during the first post-burn growing season. However, burns influenced vegetation structure by removing >95% of standing dead biomass, reducing vertical vegetation density in mid-June by 46% (1.8 + 0.2 cm on burns vs. 3.8 + 0.3 cm in unburned sites), and reducing standing residue at the end of the grazing season (early October; 523 kg ha-1 on burns vs. 585 kg ha-1 in unburned sites). Patch burning did not influence cattle weights gains (1.07 kg/steer/day in patch burned pastures vs. 1.06 kg/steer/day in control pastures). Findings will be discussed in relation to effects of patch burning on cattle distribution (measured using GPS collars in 2008) and their implications for managing breeding habitat for grassland birds of conservation concern. |
