Belowground Root Turnover and Root Traits

我们将量化地下多维生态位分化和共生物种之间的重叠，以研究资源利用的互补性，这被认为是生物多样性与生态系统功能积极关系的一个主要机制。如果植物在混合环境中生长时分割它们的资源，从而减少生态位重叠，就可能发生这种互补。这个子项目将在研究地下相互作用方面开辟新的天地，通过基于经典根核和创新的分子物种识别的根分布的详细测量，结合最先进的同位素和非同位素示踪剂应用来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地块(大的、已建立的地块和新的地块)，以及环境控制的模型系统(蒙彼利埃生态加速器实验)。此外，中观实验将提供有关物种特有的根系特征和地下竞争强度的详细信息。总而言之，这一分项目将允许直接量化生态位划分和互补性，以修正以前的数学方法(“相加分配”)，为生物多样性对生态系统功能的影响提供一个功能和机制基础。

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.