Subsurface leaf and root litter enhance soil carbon formation compared to surface litter: Direct evidence from a 13 C ‐labelled incubation experiment

作者：Ruihuan Zhang, Yuqi Wei, Bin Wei, Yixian Bi, Tongtian Guo, Gaowen Yang, Yingjun Zhang, Nan Liu · 发表于：Functional Ecology · 年份：2025 · DOI：10.1111/1365-2435.70244 · 被引用次数：2 · 研究领域：Soil Carbon and Nitrogen Dynamics、Iron oxide chemistry and applications、Biocrusts and Microbial Ecology

Abstract Litter inputs are a primary source of soil carbon (C), and balancing C sequestration against litter‐induced priming effects (PE) is critical for maintaining soil C dynamics. External disturbances (e.g. grazing or global change) can alter the spatial position of litter; however, how litter position (soil surface vs. subsurface) regulates litter‐derived C formation and PE through interactions with litter chemical, morphological and microbial traits remains unclear. We tracked the fate of litter‐derived C in a laboratory microcosm experiment using 12 types of 13 C‐labelled litter from the leaves and roots of six representative temperate grassland species spanning three functional groups: grasses, legumes and forbs. Leaf litter was incubated both on the soil surface and buried in the soil (subsurface litter), while root litter was buried only. Two destructive samplings were conducted throughout the 6‐month incubation period. We found that the effects of litter quality on litter‐derived C transformation were modulated by litter position and decomposition duration. High‐quality litter (characterized by high N concentration, low C:N ratio and low lignin concentration) promoted early accumulation of litter‐derived SOC and net C gain within 30 days of decomposition. However, as decomposition progressed to 6 months, the beneficial effects of litter quality on litter C transformation diminished. Litter position governed the relationship between litter quality and both litter‐de...