ARS | Publication request: Effects of prescribed burning and litter type on litter decomposition and nutrient release in mixed-grass prairie in Eastern Montana

Submitted to: Society of Range Management
Publication Type: Abstract Only
Publication Acceptance Date: October 1, 2010
Publication Date: February 6, 2011
Citation: Reinhart, K.O., Roth, A., Vermeire, L.T. 2011. Effects of prescribed burning and litter type on litter decomposition and nutrient release in mixed-grass prairie in Eastern Montana. Society of Range Management. 64th Annual Meeting of the Society of Range Management Abstract #0268.

Technical Abstract: Fire can affect litter decomposition and carbon (C) and nitrogen (N) dynamics. Here, we examined the effect of summer fire and three litter types on litter decomposition and litter C and N dynamics in a northern mixed-grass prairie over a 24 month period starting ca. 14 months after fire. Over all sampling dates, decomposition and nutrient mineralization (C and N) rate constants varied by litter type (alfalfa > grassland > straw) and burning treatment (burn > unburned). Litter type explained most of the variation and corresponded with differences in: C:N, % C and N, and total C and N. Over the entire study, burning had a significant but relatively small effect on decomposition rate constants. This single estimate of decomposition; however, masks temporal variation among treatments. Initially (0 to 12 months) litter decomposed slower in burned than in unburned plots and may affect how litter pools are restored. This relationship reversed from 12 to 24 months. Litter in burned plots also had lower total C and N and % C and N between 6 to 24 months suggesting a transformation in litter chemistry during the first 6 months of the study which then persisted. Decomposition in recovering burned plots lagged behind those in unburned plots but functioning appeared to be restored after ca. 2.5 years post-fire.