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

该研究股的总体目标是了解陆地生态系统内生物区室的碳流动。田间试验将在位于达姆施塔特的农业现场进行，种植永久性C3作物。13 C信号将通过将C4植物玉米作为玉米或饲料玉米栽培而引入。玉米将引入地上和地下植物碳（即不稳定和不稳定资源），而饲料玉米的碳主要来自根沉积物（即不稳定资源）。将评估基于根、细菌或真菌的主要能量途径中的碳同化和分配，同时考虑资源质量和可用性以及食物网复杂性等因素。研究股将采用同位素示踪法，查明关键生物区系，并对营养级联中的碳通量进行量化。这包括将13 C标记掺入生物标志物如脂质和核酸中。此外，还将注意总的碳平衡，即土壤系统中的周转和损失。实验评估的生物量通量（呼吸和同化率）和异速生长功能反应（捕食者-猎物相互作用）的食物网生物群内将完成图片。本研究报告的独特之处在于，

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