Fire-derived organic carbon in soil turns over on a centennial scale

• Main Authors: N. Singh, S. Abiven, M. S. Torn, M. W. I. Schmidt
• Format: Article
• Language: English
• Published: Copernicus Publications 2012-08-01
• Series: Biogeosciences
• Online Access: http://www.biogeosciences.net/9/2847/2012/bg-9-2847-2012.pdf

Pyrogenic carbon (PyC), the residue of an incomplete combustion of biomass, is considered as a carbon (C) sink due to its assumed stability in soil. PyC turnover time estimated using two modelling approaches, based on data from 16 published studies (<I>n</I> = 54) on PyC degradation, ranged from a decadal to centennial time scale, varying with initial biomass type, pyrolysis temperature, and incubation or field study. The average turnover time using a one-pool approach was 88 y, and the best estimate using a two-pool approach was 3 y for a fast-cycling pool and 870 y for a slow-cycling pool. Based on this meta-analysis, PyC cannot be assumed to persist in soils for thousands of years, and its use as a strategy for offsetting carbon emissions requires prudence and further research.