Application of Mid-Infrared Spectroscopy for parameterisation of soil carbon turnover models on a regional scale

不断变化的气候条件和相关的土地利用变化预计将改变土壤中的碳动态，从而改变土壤碳作为大气二氧化碳汇或源的作用。土壤温度等环境因素在土壤碳动态中起着重要作用，包括几种反馈机制。由于土壤和植物生产系统的巨大空间异质性，在区域尺度上对这些反馈机制的理解和建模具有挑战性。此外，对土壤有机碳库进行物理化学测定和表征以确定土壤模型的参数是昂贵和耗时的，因此不适合于区域规模所需的大量样本。因此，本研究将为区域尺度土壤有机碳动力学模型的参数化提供新的方法。一种创新的方法将是使用中红外光谱(MIRS)和热分析(TGA/DTA-DSC)相结合的方法来确定和表征土壤碳库。除了估计土壤碳库的大小外，还将评估其分解速率，以便于预测区域尺度上的土壤碳动态。一个经过验证的土壤碳模型将与Expert-N模拟软件和一个耦合的高分辨率大气气候模型相结合，有助于预测德国西南部气候条件变化下的土壤碳动态。

Changing climatic conditions and linked land use changes are expected to alter carbon dynamics in the soil and hence the role of soil carbon as a sink or source for atmospheric carbon dioxide. Environmental factors, such as soil temperature, play an important role in soil carbon dynamics including several feedback mechanisms. The understanding and modelling of these feedback mechanisms at regional scale is challenging, due to large spatial heterogeneity of soil and plant production systems. In addition, physical-chemical determination and characterisation of soil organic carbon pools to parameterise soil models is costly and time consuming and thus unsuitable for large numbers of samples required at regional scale. Hence, the current study will develop new methods to parameterise soil organic carbon dynamics models at regional scale. An innovative approach will be the determination and characterisation of soil carbon pools using mid-infrared spectroscopy (MIRS) coupled with thermo-analysis (TGA/DTA-DSC). Apart from estimating the size of soil carbon pools, their decomposition rates will be assessed, facilitating prediction of soil C dynamics at regional scale. A validated soil carbon model will, in conjunction with Expert-N modelling software and a coupled high resolution atmosphere climate model, facilitate prediction of soil C dynamics under changing climatic conditions in Southwest Germany.