[Effects of addition of leaf litter with different chemical properties on soil organic carbon mineralization and priming effect]

Litter inputs can affect the mineralization of soil organic carbon (SOC). However, it is yet unknown how the input of leaf litter with different chemical properties drives SOC mineralization and priming effect. In this study, ¹³C-labeled leaf litter of six tree species were added to soil cores (10 cm depth) collected from a natural secondary forest in subtropical region. We examined the effects of different leaf litters on total soil CO₂, litter-derived and soil-derived CO₂ emission rates and accumulation and priming effect. We further examined the relationships between litter chemical properties and CO₂ accumulation and priming effect. Our results showed that leaf litter addition increased total soil CO₂ and soil-derived CO₂ emission rates and accumulations, and that there were positive priming effects ranging from 68% to 128%. Soil organic carbon mineralization and priming effects varied among tree species. The Pearson correlation and stepwise multiple linear regression analysis showed that the litter-derived CO₂ accumulation had negative correlation with leaf litter C, P and cellulose concentrations, whereas the soil-derived CO₂ accumulation were positively correlated to litter C:N and lignin:N. The results implied that tree species could influence SOC mineralization and litter-induced priming effect. Thus it could mitigate soil C loss when we afforested plantation with high quality leaf litter in subtropical region.