Rothamsted Research, Climate Change and Carbon Cycling Research Group: Black Carbon
Saran Sohi, Climate Change and Carbon Cycling Research Group, Rothamsted Research, UK
In addition to microbial decomposition, combustion is a significant return route for carbon sequestered into vegetation via photosynthesis. On the millennial timescale fire has been an important feature in most landscapes, and in some natural ecosystems (such as tropical forests and savannah grasslands) the cycle of burning and regeneration is characteristic and defined. Fire has also been an important feature in agriculture, both in shifting "slash and burn" cultivation but also for disposal of crop wastes, eliminating disease or controlling nutrient status. Over time burning will not only have accelerated the general cycling of carbon between atmosphere and vegetation, but also diverted a small proportion into highly recalcitrant charcoal (biochar) fraction that resides in the soil (Figure 1).
See poster: Evaluating C dynamics in Terra Preta presented at WCSS, July 2006