Processes of litter and soil organic matter transformation during extreme drying/wetting as assessed by compound-specific isotope approaches

通过化合物特异性同位素方法评估极端干燥/湿润期间凋落物和土壤有机质转化的过程

• 批准号: 68810257
• 负责人: Professor Dr. Bruno Glaser
• 金额: --
• 依托单位: Ökopedologie der gemäßigten Zonen
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2012-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/68810257?language=en
• 关键词: Processes; litter; soil; organic; matter

Recently, intensive droughts followed by heavy rainfall can already be observed in Europe as proposed by climate models. Shifts in amount, intensity and frequency of precipitation could change soil structure and soil organic matter quality and thus turnover in temperate forest ecosystems. Contradicting results have been reported from drying and wetting experiments in field and laboratory studies or from observations of natural drying and wetting periods. To verify different interpretations, a combination of stable and radio-isotopes and biomarker .analyses seems a promising tool. This can be achieved by establishing tracer experiments in the drying and wetting fields (13C and 15NJ and in controlled laboratory studies (14C, 13C, and 15N) and by analysing the 13C, 14C and 15N signatures not only in the bulk SOM but also in biomarkers characterizing chemically defined SOM pools, e.g. microbially and plant-derived sugars, phospholipid fatty acids (PLFA) and benzenepolycarboxylic acids (BPCA). The combination of biomarker and isotope (δ13C, 14C and δ 15N) analysis allows not only deducing SOM turnover after drying / wetting but also to identify the involved microbial community and the fate of chemically defined compounds during SOM decomposition and turnover under the experimental manipulations.

最近，正如气候模型所建议的那样，在欧洲已经观察到大量干旱随后发生了大雨。精度的数量，强度和频率的变化可能会改变土壤结构和土壤有机物质量，从而改变温度森林生态系统的周转率。据报道，从现场和实验室研究中的干燥和润湿实验或自然干燥和润湿期的观察结果据报道。为了验证不同的解释，稳定和放射性异构体和生物标志物的结合似乎是有望的工具。这可以通过在干燥和润湿场（13C和15NJ以及对照实验室研究（14C，13C和15N）中建立示踪剂实验，以及分析13C，14C和15N的特征，不仅在散装体内，而且在生物标记中，还可以在生物标记中进行化学定义的体积和植物含量（例如，植物含量），并分析13C，14C和15N的特征，例如苯甲酸核酸（BPCA）。