Litter quality assessed by solid state 13C NMR spectroscopy predicts decay rate better than C/N and Lignin/N ratios
Litter quality assessed by solid state 13C NMR spectroscopy predicts decay rate better than C/N and Lignin/N ratios
复制标题
DOI：
10.1016/j.soilbio.2012.03.003
复制
发表时间：
2013-01-01
影响因子：
9.7
通讯作者：
Mazzoleni, Stefano
中科院分区：
文献类型：
--
作者：
Bonanomi, Giuliano;Incerti, Guido;Mazzoleni, Stefano
对凋落物分解速率的预测对于模拟陆地生态系统中的生物地球化学循环和预测有机碳和养分储量平衡至关重要。除气候条件外，凋落物质量被认为是影响腐烂率的主要因素，传统上是通过未分解材料的C/N和木质素/N比来评估的。本文采用固体碳谱和化学分析方法，对不同类型的凋落物在不同温度和水分条件下的分解过程进行了研究。统计比较分析表明，C/N和木质素/N比可以用来描述未分解凋落物的质量，但不能预测已经分解的物质的质量损失，这两个比率在不同的分解阶段与腐烂速率呈现不同的趋势。基于C-13核磁共振谱的主成分回归(PCR)模型，通过随机选择两组凋落物类型进行拟合和交叉验证，显示出对整个分解过程中观测到的衰减率的高度拟合预测。碳水化合物的O-烷基C和木质素的甲氧基C分别对应的简单比70-75/52-57与腐烂率的相关性最高。这些发现加深了我们对凋落物质量的理解，并提高了我们预测分解动力学的能力。基于C-13核磁共振的70-75/52-57比被提出作为C/N和木质素/N比的替代，用于实验和模拟工作。(C)2012爱思唯尔有限公司。保留所有权利。
Predictions of litter decomposition rates are critical for modelling biogeochemical cycling in terrestrial ecosystems and forecasting organic carbon and nutrient stock balances. Litter quality, besides climatic conditions, is recognized as a main factor affecting decay rates and it has been traditionally assessed by the C/N and lignin/N ratios of undecomposed materials. Here, solid state C-13 NMR spectroscopy and proximate chemical analysis have been used to characterize litter organic C in a litterbag experiment with 64 different litter types decomposing under controlled conditions of temperature and water content. A statistical comparative analysis provided evidence that C/N and lignin/N ratios, showing different trends of correlation with decay rates at different decomposition stages, can be used to describe the quality of undecomposed litter, but are unable to predict mass loss of already decomposed materials. A principal component regression (PCR) model based on C-13 NMR spectra, fitted and cross-validated by using either two randomly selected sets of litter types, showed highly fitting predictions of observed decay rates throughout the decomposition process. The simple ratio 70-75/52-57 corresponding to O-alkyl C of carbohydrates and methoxyl C of lignin, respectively, showed the highest correlation with decay rate among different tested parameters. These findings enhance our understanding of litter quality, and improve our ability to predict decomposition dynamics. The C-13 NMR-based 70-75/52-57 ratio is proposed as an alternative to C/N and lignin/N ratios for application in experimental and modelling work. (C) 2012 Elsevier Ltd. All rights reserved.