INter- and intra-specific SIze Diversity of phytoplankton and its impacts on Ecosystem functions (INSIDE)

生物多样性对生态系统中能量和物质的生产和再循环有各种影响。生物多样性通常是以物种数量来衡量的，尽管其他指标，如功能性状多样性，可以为调查生物多样性和生态系统功能之间的关系提供有效的定量基础。基于特征的方法在生物多样性研究中已经变得非常普遍。然而，大多数研究都集中在种间性状变异（由物种组成驱动），从而忽略了种内性状变异（基因型和表型）的元素如何影响群落结构和生态系统功能。在这里，我们提出了一个项目，结合数学建模与实验室实验，以量化的相对影响内和种间性状多样性的社区结构和功能的海洋浮游生物群落。我们解决这一问题，进行实验的自然群落组合和混合物的选定的克隆在不同的营养和放牧制度，并在小（烧瓶）和大规模（围隔生态系统）的实验设置。与此同时，将开发一个基于个体显性特征的模型，以解释个体间和个体内大小多样性的变化，并量化两个层次的多样性之间的功能替代性。因此，这种协同增效的方法将为形成生物多样性和生态系统功能关系的相关机制（物种组成的变化以及基因型和表型变异）提供新的线索。

Biodiversity has various impacts on production and re-circulation of energy and matter in an ecosystem. It is typically measured in terms of the number of species, albeit alternative metrics, such as functional trait diversity, can provide an effective quantitative basis to investigate relationships between biodiversity and ecosystem functions. Trait-based approaches have become very common in biodiversity research. Most studies, however, focus on inter-specific trait variations (driven by species composition), thus overlooking how intra-specific elements of trait variability (genotypic and phenotypic) affect the community structure and the resulting ecosystem functions. Here we propose a project that combines mathematical modelling with laboratory experiments to quantify the relative impacts of intra- and inter-specific trait diversity on the community structure and functioning of marine planktonic communities. We tackle this by performing experiments of natural community assemblages and mixtures of selected clones at different nutrient and grazing regimes, and in small (flasks) and large-scale (mesocosms) experimental settings. In parallel, an individual-explicit trait-based model will be developed to account for inter- and intra-specific variations of size diversity and to quantify the functional substitutability between the two levels of diversity. This synergistic approach will thus shed new light on the relevant mechanisms (shifts in species composition and genotypic and phenotypic variations) shaping biodiversity and ecosystem function relationships.