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

Abstract

Black carbon (BC) from incomplete combustion of biomass and fossil fuel is widespread in sediments and soils because of its high stability in nature and is considered an important component of the global carbon sink. However, knowledge of BC stocks and influencing factors in forest ecosystems is currently limited. We investigated soil BC contents in burned boreal forests of the Great Khingan Mountains, northeast China. We collected soil samples from 14 sites with different fire severities, slope positions and aspects. The samples were analyzed by the chemo-thermal oxidation method to obtain their BC concentrations. The BC concentrations of the studied soils ranged from 0.03 to 36.91 mg C g −1 , with a mean of 1.44 ± 0.11 mg C g −1 . BC concentrations gradually decline with depth, and that was significantly less in the 20-30 cm layer compared to all shallower layers. Forests burned by moderate-severity fires had the highest soil BC, the shady aspect had higher soil BC than the sunny aspect. Our results provide some basic data for evaluating the soil BC sink in boreal forests, which is a useful amendment to current carbon budget and carbon cycle in boreal forest ecosystems.

Pyrogenic Carbon Generation From Fire and Forest Restoration Treatments

“…From these data it was hard for us to further generalize correlations between environmental variables and PyC production per single fire event. It is possible that the differences in soil and site properties across geographically distinct sites contributed to the variation in PyC persistence; however, it is more likely that fire and fuel characteristics including burn temperature, fuel composition and loading, and fuel moisture were the strongest drivers of variation in PyC production across different studies (Huang et al, 2018). This is supported by our data synthesis which showed that the higher amount of PyC production was observed under "wildfire" compared with "Rx fire" (Figure 1A), and under "thinning + Rx fire" when compared with "Rx fire only" (Figure S1).…”

Spatiotemporal variability of fire effects on soil carbon and nitrogen: A global meta‐analysis

“…However, the residence time of PyC in soil is overestimated in some cases (Zimmermann et al, 2012), and major losses of soil PyC may also occur due to erosion (Abney & Berhe, 2018) or dissolution (Bostick et al, 2018). Although a few individual studies have reported fire‐induced changes in soil PyC (e.g., Huang et al, 2018; Krishnaraj et al, 2016; Miesel et al, 2018; Santín et al, 2015; Santos et al, 2017), the results were highly variable among these studies. Until now, we lacked a comprehensive understanding of the qualitative changes in soil C, specifically, the fire‐induced changes in soil PyC, hampering our ability to comprehensively assess soil C cycles post‐fire.…”

Heat Analysis and Fire Prevention of Timber Buildings in Southwest China Based on Fractal and Seepage Theory

“…Except the tiles on the roof, the buildings are almost entirely made of timber, lap jointed by numerous tall and short timber components. Due to the large difference between building timbers in pyrolysis parameters, the numerical simulation of fire spread features using experimental data often has a large error [14][15][16]. Qin et al [17] conducted kinetic fitting for the materials of timber buildings in different stages of pyrolysis, established the relevant kinetic equations for pyrolysis, built a simulation model for the fire propagation inside timber buildings, and compared the fire spread features of timber buildings under different fire source locations and ventilation conditions, as well as their influencing factors.…”