Aims

Data about woody debris (WD) decomposition are very scarce for the Mediterranean basin. The specific aim of this work is to explore the relationships between WD traits with the decay rate.

Methods

We carried out a three-year litterbag decomposition experiment using ten WD types incubated in two plant communities (i.e. shrubland and woodland) and in laboratory conditions. WD was characterized for 31 chemical and anatomical traits, including macro- and micronutrients, lignin, and cellulose as well as organic chemistry by Solid-state Cross-Polarization Magic Angle Spinning Carbon-13 Nuclear Magnetic Resonance (¹³C CPMAS NMR) and Fourier transform infrared spectroscopy/ Attenuated Total Reflection (FT-IR/ATR spectroscopy).

Results

WD decay rate was negatively associated with di-O-alkyl, lignin/N and C/N ratios, but positively with N concentration. Less consistent but positive correlations were recored for K, Mn, and Na concentration. The alkyl C and carboxylic C regions, associated with aliphatic and amide compounds, was positively correlated with WD decomposition. Conversely, di-O-alkyl C and O-alkyl C fractions, largely associated with cellulose and hemicellulose, were negatively correlated with WD decay rate. Finally, the positive correlation between Na concentration and WD mass loss in field conditions suggest a role of this neglected micronutrient for wood decomposition. WD specific density and anatomical features, have a minor capability to explain decomposition rate.

Conclusions

Our findings demonstrate a major role of WD chemical traits in explaining the variability of decomposition in Mediterranean ecosystems.

中文翻译：

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地中海生态系统中木屑的分解：木化学和解剖特征的作用

目的

在地中海盆地，关于木屑碎片（WD）分解的数据非常稀少。这项工作的具体目的是探索WD性状与衰减率之间的关系。

方法

我们使用在两个植物群落（即灌木丛和林地）和实验室条件下孵育的十种WD类型进行了为期三年的垃圾袋分解实验。通过固态交叉极化魔角旋转碳13核磁共振（¹³ C CPMAS NMR）和傅里叶变换，对WD表征了31种化学和解剖学特征，包括大量和微量营养素，木质素和纤维素以及有机化学红外光谱/衰减全反射（FT-IR / ATR光谱）。

结果

WD衰减速率与二-O-烷基，木质素/ N和C / N比呈负相关，而与N浓度呈正相关。钾，锰和钠浓度的一致性较低，但呈正相关。与脂族和酰胺化合物相关的烷基C和羧基C与WD分解呈正相关。相反，与纤维素和半纤维素主要相关的二-O-烷基C和O-烷基C馏分与WD衰减率负相关。最后，在田间条件下，Na浓度与WD质量损失之间呈正相关，表明这种被忽略的微量营养素对木材分解的作用。WD的比重和解剖特征对分解速率的解释能力较弱。

结论

我们的发现证明了WD化学性状在解释地中海生态系统中的分解变化中起着重要作用。