Minor changes in soil organic carbon and charcoal concentrations detected in a temperate deciduous forest a year after an experimental slash-and-burn

Abstract

Abstract. Anthropogenic fires affected the temperate deciduous forests of Central Europe over millennia. Biomass burning releases carbon to the atmosphere and produces charcoal, which potentially contributes to the stable soil carbon pools and is an important archive of environmental history. The fate of charcoal in soils of temperate deciduous forests, i.e. the processes of charcoal incorporation and transportation and the effects on soil organic matter are still not clear. We investigated the effects of slash-and-burn at a longterm experimental burning site and determined soil organic carbon and charcoal carbon concentrations as well as the soil lightness of colour (L*) in the topmost soil material (0-1, 1-2.5 and 2.5-5 cm depths) before, immediately after the fire and one year later. The main results are that (i) only a few of the charcoal particles from the forest floor were incorporated into the soil matrix, presumably by soil mixing animals. In the 0-1 cm layer, during one year, the charcoal C concentration increased only by 0.4 g kg −1 and the proportion of charcoal C to SOC concentration increased from 2.8 to 3.4%; (ii) the SOC concentrations did not show any significant differences; (iii) soil lightness decreased significantly in the topmost soil layer and correlated well with the concentrations of charcoal C (r=−0.87**) and SOC (r=−0.94**) in the samples from the 0-5 cm layer. We concluded that Holocene biomass burning could have influenced soil charcoal concentrations and soil colour.

Short-term changes in soil Munsell colour value, organic matter content and soil water repellency after a spring grassland fire in Lithuania

“…In fires of high severity the temperatures increase soil redness, especially at temperatures of 300-500 • C (Terefe et al, 2008) or > 600 • C ( Ketterings and Bigham, 2000;Ulery and Graham, 1993), which is attributed to the destruction of the organic matter and increase in iron oxides such as hematite (Terefe et al, 2005). In contrast, low-severity fires darken the soil as a result of the incorporation of ash/charcoal into the soil surface and matrix (Eckmeier et al, 2007). These authors observed that soil lightness of colour had a significant negative correlation with charcoal carbon.…”

“…With time, despite the significant differences of soil Munsell colour value between plots, the soil became lighter in the burned plot. This may be attributed to the incorporation of burned residues into the first top centimetres of the soil, reducing soil surface darkness (Eckmeier et al 2007;Pereira et al, 2012b, c;Woods and Balfour, 2011). The black ash cover has implications in the soil environment in the immediate period after the fire (e.g.…”

“…The Munsell value gives information about soil darkness/lightness. Low values correspond to dark soils and high values to light soils (Eckmeier et al, 2007). All the soil value analyses were carried out by the same person under the same light conditions.…”

“…Eckmeier et al (2007) studied the effects of a slash-and-burn fire on soil lightness compared to soil in an unburned plot. However, the study was carried out immediately after the fire and 1 year after the fire.…”

Short-chain n-alkanes (C16–20) in ancient soil are useful molecular markers for prehistoric biomass burning

“…After burning events, either wildfires or deliberate burning, a fraction of the charred organic material left on the soil surface is incorporated into the soil mineral matrix (Eckmeier et al, 2007). The lipid distribution patterns in some soils in Spain that were affected by vegetation burning were dominated by short-chain even carbon numbered n-alkanes (Tinoco et al, 2006).…”