Impact of modified temperature and precipitation regime on soil microorganisms and carbon cycling in arable soils

陆地生态系统中的碳循环通过释放或封存额外的大气二氧化碳，为气候变化提供了一种反馈机制。然而，陆地碳循环对温度和降水变化相互作用的响应尚不清楚。本项目旨在研究气候变化下土壤有机碳周转与微生物丰度、活性和多样性之间的关系。将建立一个田间试验，以改变耕地的温度和降水。首先，我们将通过应用呼吸、酶活性和微生物和真菌生物量测量来量化气候条件变化下碳矿化的季节变化。其次，阐明凋落物质量和分解活性变化对凋落物分解的交互作用。这将通过提取、克隆和测序真菌DNA与真菌群落结构联系起来。第三，我们将通过稳定同位素技术与细菌和真菌生物标志物（PLFAs和麦角甾醇）的提取相结合，追踪真菌和细菌群落的凋落物碳通量。总体而言，该项目将提供有关生物地球化学循环对气候变化响应的宝贵信息，从而有助于改善未来气候的情景。

Carbon cycling in terrestrial ecosystems provides a feedback mechanism to climate change by releasing or sequestering additional atmospheric CO2. However, the response of terrestrial carbon cycling to the interactive effects of a changing temperature and precipitation regime is still unclear. This project aims to relate soil organic carbon turnover under a modified climate to microbial abundance, activity and diversity. A field experiment will be established to modify temperature and precipitation on a arable field. First, we will quantify the seasonal variation of carbon mineralisation under changed climatic conditions by applying respiration, enzyme activity and microbial and fungal biomass measurements. Second, we will clarify the interactive effects of a changed litter quality and decomposition activity on litter decomposition. This will be linked to the fungal community structure by extracting, cloning and sequencing fungal DNA. Third, we will trace the litter carbon flux through the fungal and bacterial community by coupling stable isotope techniques with the extraction of bacterial and fungal biomarkers (PLFAs and ergosterol). Overall, this project will provide valuable information on the response of biogeochemical cycles to climate change and therefore will help to improve scenarios of future climate.