Soil Organic Carbon and Its Fractions Across Vegetation Types: Effects of Soil Mineral Surface Area and Microaggregates

Abstract

Soil organic carbon (SOC) can act as a sink or source of atmospheric carbon dioxide; therefore, it is important to understand the amount and composition of SOC in terrestrial ecosystems, the spatial variation in SOC, and the underlying mechanisms that stabilize SOC. In this study, density fractionation and acid hydrolysis were used to assess the spatial variation in SOC, the heavy fraction of organic carbon (HFOC), and the resistant organic carbon (ROC) in soils of the southern Hulun Buir region, northeastern China, and to identify the major factors that contribute to this variation. The results showed that as the contents of clay and silt particles (0-50 μm) increased, both methylene blue (MB) adsorption by soil minerals and microaggregate contents increased in the 0-20 and 20-40 cm soil layers (P < 0.05). Although varying with vegetation types, SOC, HFOC, and ROC contents increased significantly with the content of clay and silt particles, MB adsorption by soil minerals, and microaggregate content (P < 0.05), suggesting that soil texture, the MB adsorption by soil minerals, and microaggregate abundance might be important factors influencing the spatial heterogeneity of carbon contents in soils of the southern Hulun Buir region.

Short-term effects of plant litter addition on mineral surface characteristics of young sandy soils

“…Weathering processes typically increase SSA and create a higher potential for SOM sorption (Kahle et al, 2004;Wu et al, 2009). Greater amounts of mineral surfaces provided more sorption sites for SOM.…”

“…Weathering processes typically increase SSA of mineral soils and create a higher potential for SOM sorption (Kahle et al, 2004;Wu et al, 2009). However, most of these findings were derived from long-term chronosequence studies of relatively mature soils (Mavris et al, 2010;White et al, 1996;Wissing et al, 2014).…”

Effects of three different biochars on aggregate stability, organic carbon mobility and micronutrient bioavailability

“…TOC residence time and pool size in microaggregates (Wu et al, 2009). Through a combination of physical protection and chemical complexation this carbon source may have been protected from microbial decay (Powers and Schlesinger, 2002).…”

Effects of prediction methods for detecting the temporal evolution of soil organic carbon in the Hilly Red Soil Region, China

“…Soil organic carbon (SOC) is not only an important indicator of soil quality, but it is also an essential part of carbon pools in the terrestrial ecosystem (Lal 2004;Wu et al 2009;Maia et al 2010). Due to various impact factors, especially human's activities, SOC content is undergoing dynamic processes (Schöning et al 2006;Soil Survey Staff 2008;Bayramin et al 2009;Zhang et al 2009).…”