Integrated aggregate turnover and soil organic carbon sequestration using rare earth oxides and 13C isotope as dual tracers

Effects of Natural Succession and Forest Landscape Restoration on Soil C and Aggregate-Associated C in the Central Loess Plateau, China

“…Macroaggregates are formed by combining plant residues (litter and root biomass) and root exudates with microaggregates and silt + clay particles. Hence, an increase in the proportion of macroaggregates leads to a decrease in the proportions of microaggregates and silt + clay particles ( Six et al 2004 ;Gupta and Germida 2015 ;Liu et al 2023 ). However, the abilities of the two vegetation types to increase soil aggregation was similar (see Fig.…”

“…Soil aggregates can be divided according to particle size classification into three particle sizes: macroaggregates ( > 0.25 mm), microaggregates (0.25 −0.053 mm), and silt + clay particles ( < 0.053 mm) ( Dong et al 2022a ). The dynamics of soil C can be further understood by dividing soil C into macroaggregate C, microaggregate C, and silt + clay particles C ( Yao et al 2019 ;Rong et al 2020 ;Liu et al 2023 ). As such, aggregates with different particle sizes respond differently to vegetation restoration ( Zhong et al 2019 ;Liu et al 2023 ).…”

“…The dynamics of soil C can be further understood by dividing soil C into macroaggregate C, microaggregate C, and silt + clay particles C ( Yao et al 2019 ;Rong et al 2020 ;Liu et al 2023 ). As such, aggregates with different particle sizes respond differently to vegetation restoration ( Zhong et al 2019 ;Liu et al 2023 ). Compared with microaggregates and silt + clay particles, macroaggregates are more susceptible to land-use change, so macroaggregate C is more sensitive to environmental change ( Six et al 2004 ;Yao et al 2019 ;Liu et al 2023 ).…”

“…As such, aggregates with different particle sizes respond differently to vegetation restoration ( Zhong et al 2019 ;Liu et al 2023 ). Compared with microaggregates and silt + clay particles, macroaggregates are more susceptible to land-use change, so macroaggregate C is more sensitive to environmental change ( Six et al 2004 ;Yao et al 2019 ;Liu et al 2023 ). An increase in the proportion of macroaggregates and macroaggregate C content after vegetation restoration is considered to be the main reason for the increase in soil C stocks ( Yao et al 2019 ;Zhong et al 2019 ).…”

“…An increase in the proportion of macroaggregates and macroaggregate C content after vegetation restoration is considered to be the main reason for the increase in soil C stocks ( Yao et al 2019 ;Zhong et al 2019 ). This is because the formation of macroaggregates provides physical protection to OC, preventing the decomposition of C by microorganisms ( Wilpiszeski et al 2019 ;Liu et al 2023 ). In addition, an increase in the proportion of macroaggregates increases the resistance of the soil to erosion and reduces the loss of Crich topsoil, which contributes to soil C accumulation ( Zheng et al 2021 ).…”