Department of Agronomy, Iowa State University, Ames, IA, 50011, USA.
United States Department of Agriculture, Agricultural Research Service, Rangeland Resources Research Unit, Ft. Collins, CO, 80526, USA.
Glob Chang Biol. 2015 Sep;21(9):3200-9. doi: 10.1111/gcb.12982. Epub 2015 Jul 19.
Labile, 'high-quality', plant litters are hypothesized to promote soil organic matter (SOM) stabilization in mineral soil fractions that are physicochemically protected from rapid mineralization. However, the effect of litter quality on SOM stabilization is inconsistent. High-quality litters, characterized by high N concentrations, low C/N ratios, and low phenol/lignin concentrations, are not consistently stabilized in SOM with greater efficiency than 'low-quality' litters characterized by low N concentrations, high C/N ratios, and high phenol/lignin concentrations. Here, we attempt to resolve these inconsistent results by developing a new conceptual model that links litter quality to the soil C saturation concept. Our model builds on the Microbial Efficiency-Matrix Stabilization framework (Cotrufo et al., 2013) by suggesting the effect of litter quality on SOM stabilization is modulated by the extent of soil C saturation such that high-quality litters are not always stabilized in SOM with greater efficiency than low-quality litters.
不稳定的、“高质量”的植物凋落物被假设可以促进矿质土壤中受物理化学保护而不易快速矿化的土壤有机物质（SOM）的稳定。然而，凋落物质量对 SOM 稳定的影响并不一致。高质量凋落物的特点是氮浓度高、碳氮比低、酚/木质素浓度低，但并不总是比氮浓度低、碳氮比高、酚/木质素浓度高的“低质量”凋落物更有效地稳定在 SOM 中。在这里，我们试图通过建立一个将凋落物质量与土壤 C 饱和度概念联系起来的新概念模型来解决这些不一致的结果。我们的模型是在微生物效率-基质稳定框架（Cotrufo 等人，2013）的基础上建立的，该框架表明凋落物质量对 SOM 稳定的影响受土壤 C 饱和度的调节，因此高质量凋落物并不总是比低质量凋落物更有效地稳定在 SOM 中。
