Belowground Root Turnover and Root Traits

我们将量化地下多维生态位分化和重叠共存物种之间的资源利用互补性，这被认为是一个积极的生物多样性生态系统功能关系的主要机制。如果植物在混合生长时分配其资源，可能会发生这种互补性，从而减少生态位重叠。该分项目将在地下相互作用研究方面开辟新天地，具体做法是根据传统的根取芯和创新的分子物种鉴定方法，结合最先进的同位素和非同位素示踪剂应用，详细测量根的分布，以量化根在空间和时间上的活动模式。这项研究将使用耶拿实验的所有试验区（大型、已建试验区和新试验区）以及环境控制模型系统（蒙彼利埃生态试验区）。此外，围隔实验将产生详细的资料，物种特有的根性状和地下竞争强度。总之，这个子项目将允许直接量化生态位划分和互补性，修正以前的数学方法（“加法划分”），为生物多样性对生态系统功能的影响提供功能和机制基础。

We will quantify belowground multidimensional niche differentiation and overlap among co-occurring species to study resource use complementarity, which is thought to be one major mechanism for positive biodiversity-ecosystem functioning relationships. Such complementarity may occur if plants partition their resources when growing in mixtures, leading to reduced niche overlap. This subproject will break new ground in the study of belowground interactions by detailed measurements of root distribution based on classical root coring and innovative molecular species identification, combined with state-of-the-art isotopic and non-isotopic tracer applications to quantify root activity patterns in space and time. The study will use all plots of the Jena Experiment (large, established plots and new plots), as well as the environmentally controlled model systems (Montpellier Ecotron Experiment). In addition, mesocosm experiments will yield detailed information on speciesspecific root traits and belowground competitive intensity. In sum, this subproject will allow a direct quantification of niche partitioning and complementarity that amends former mathematical approaches (“additive partitioning”), to provide a functional and mechanistic basis for biodiversity effects on ecosystem functioning.