Spatial and temporal dynamics of the soil charcoal pool in relation to fire history in a boreal forest landscape

Abstract

Charcoal pools in boreal forest soils constitute considerable amounts of slow cycling organic matter that is important in the global carbon cycle. However, these pools are characterized by spatiotemporal variations that are not well understood. Here, we have analyzed the charcoal pool in 100 soil samples to determine charcoal stock species origin and how the size and age of this pool varies across different spatial scales in a Norwegian boreal forest landscape including forests that differ in terms of tree-species composition, tree density, and recent fire histories. The size of the charcoal pool was site-specific and highly variable, ranging from 0 to 2108 g·m–2. Geostatistical analyses showed that the charcoal pool was only weakly spatially structured at fine spatial scales (metres) and broader between-site scales (100s of metres). Unexpectedly, there was no significant relationship between the amount of charcoal and contemporary forest composition and density, although there was proportionally more charcoal from broadleaved trees in today’s Scots pine forests than in the Norway spruce forests. When relating this information to the fire history, the results indicate that charcoal is lost at a millennial time scale.

Charcoal in Organic Horizon and Surface Mineral Soil in a Boreal Forest Fire Chronosequence of Western Quebec: Stocks, Depth Distribution, Chemical Properties and a Synthesis of Related Studies

“…Similar to our results, high spatial variability has been observed elsewhere (Ohlson et al, 2006(Ohlson et al, , 2009Kasin et al, 2017), as well as the common occurrence of charcoal/PyC at the interface of the organic and mineral layers (Cyr et al, 2005;Ohlson et al, 2009;Hart and Luckai, 2014;Soucémarianadin et al, 2015a). Our depth profiles also show charcoal layers within the organic horizon of some LO plots.…”

Effects of Fire Severity and Topography on Soil Black Carbon Accumulation in Boreal Forest of Northeast China

“…The soil BC in unburned plots may be caused by historical forest fires. Repeated fires could consume a portion of soil BC previously accumulated [14]. In addition, wildfires may result in soil erosion which could deliver soil BC to rivers [55] and to the mountain hill foot [56].…”

“…BC is widespread in sediments and soils because of its refractory nature and the common occurrence of combustion [8][9][10]. Some studies have shown that much of BC is stored in boreal forest soils [11][12][13][14]. In addition, fire frequency will increase in boreal forest ecosystems with the climatic warming [15] and this trend could be further enhanced by the end of this century [16].…”

A Late Mesolithic Forager Dispersal Caused Pre‐agricultural Demographic Transition in Norway

“…For instance, soil charcoal analysis from North America covering the Holocene found 'no decrease of charcoal mass with time' (De Lafontaine et al 2011, 572). Conversely, several studies from Eastern Norway argue that charcoal degradation in natural soil profiles (podsol) are heavily dependent on recurring forest, most importantly forest fires (Bjune et al 2013;Kasin et al 2017;Olhson et al 2017). Until regional empirical models for the correction of the radiocarbon date record in for example Eastern and Western Norway are constructed, application of more general models on the STAGED dataset, such as the exponential function proposed by Surovell et al (2009), is not recommended by the author and was not applied in this study.…”