Black carbon in a temperate mixed-grass savanna

Black carbon in a temperate mixed-grass savanna
X. Daia, T.W. Boutton a,*, B. Glaser b, R.J. Ansley c, W. Zech b
Soil Biology & Biochemistry 37 (2005) 1879–1881

Abstract
Black carbon (BC) or charcoal is thought to represent an important component of the carbon cycle, but has seldom been quantified in soils. We quantified soil BC in a temperate mixed-grass savanna in the southern Great Plains using benzenecarboxylic acids as molecular markers for BC. Soils were collected from four fire treatments (repeated summer fires in 1992 and 1994; repeated winter fires in 1991, 1993 and 1995;
alternate-season fires in winter 1991, summer 1992, and winter 1994; and unburned control) at 0–10 and 10–20 cm depth in 1996. Black carbon concentrations ranged from 50 to 130 g BC kgK1 of soil organic carbon (SOC), or from 0.55 to 1.07 g BC kgK1 of whole soil in this mixed grass savanna. The BC contribution to SOC increased significantly with soil depth (P!0.05). Repeated fires increased BC slightly compared to the unburned controls; however, the effects of repeated fires on BC were not statistically significant in this mixed-grass savanna. Results of this study provide estimates of BC concentrations for native, uncultivated mixed-grass savanna, and indicate that 2–3 fires have little effect on the size of the soil BC pool in this region.
2005 Elsevier Ltd. All rights reserved.

Keywords: Black carbon; Prescribed fire; Mixed-grass savanna; Soil carbon sequestration; Soil organic carbon; Benzenecarboxylic acids; Charcoal; Carbon
cycle

a Department of Rangeland Ecology and Management, Texas A&M University, College Station, TX 77843-2126, USA
b Institute of Soil Science and Soil Geography, University of Bayreuth, D-95440 Bayreuth, Germany
c Texas Agricultural Experiment Station, P.O. Box 1658, Vernon, TX 76384, USA