FOR 918: Carbon Flow on Belowground Food Webs Assessed by Isotope Tracers

研究股的总体目标是了解碳通过陆地生态系统内生物隔间的流动情况。田间试验将在达姆施塔特的一个农业地点进行，永久种植C3作物。13C信号将通过将C4植物玉米种植为玉米或饲料玉米来引入。玉米将引入地上和地下的植物碳(即不稳定和顽固的资源)，而对于饲料玉米，碳主要来自根沉积(即不稳定的资源)。将考虑资源质量和可用性以及食物网的复杂性等因素，评估以根、细菌或真菌为基础的主要能源途径中的碳同化和分配。研究股将应用同位素示踪法确定关键生物群，并量化营养级联中的碳通量。这包括将13C标记加入到脂类和核酸等生物标记物中。此外，还将注意总体碳平衡，即土壤系统的周转和损失。对食物网生物群内的生物量通量(呼吸和同化速率)和异速生长功能反应(捕食者-猎物相互作用)进行的实验评估将完成这一图景。这项研究的独特之处在于它的目的是

The overall goal of the Research Unit is to understand the flow of carbon through biotic compartments within terrestrial ecosystems. Field experiments will be performed at an agricultural site located at Darmstadt with permanent C3 crop. The 13C signal will be introduced by cultivating the C4 plant Zea mays either as corn or fodder maize. Corn maize will introduce above- and belowground plant carbon (i.e. labile and recalcitrant resources), whereas with fodder maize carbon predominantly derives from rhizodeposits (i.e. labile resources). Carbon assimilation and partitioning in the major energy pathways based on roots, bacteria or fungi will be assessed, taking into consideration the factors as resource quality and availability as well as food web complexity. The Research Unit will apply isotope tracer methods for identification of key biota and quantification of the carbon flux in the trophic cascade. This includes the incorporation of 13C label into biomarkers such as lipids and nucleic acids. In addition, attention will be given to the overall carbon balance, i.e. turnover and losses in the soil system. Experimentally assessed biomass-fluxes (respiration and assimilation rates) and allometric functional responses (predator-prey interactions) within food web biota will complete the picture. The present study is unique in its aim to