Contribution of plant intraspecific diversity to carbon turnover in grassland

现在有大量证据表明，植物生物多样性影响生态系统的运作方式，例如碳的回收或储存速度。但是“生物多样性”有许多组成部分，我们最近表明，“群落组成”，而不是物种或植物功能类型的数量，是调节碳周转率的关键因素。然而，生物多样性的一个基本上被忽视的组成部分是个体一级的变异，即特定物种的基因型变异或种内多样性。我们已经表明，在一个社区中的个人的数量有显着的影响，通过影响特定植物物种的竞争能力对植物生产力。我们还表明，每个物种的基因型数量对根真菌多样性有显着影响，其他研究也表明，与碳循环相关的关键植物性状在物种内是高度可变的。这些研究表明，种内多样性对碳周转具有潜在的重要影响。因此，本项目旨在发现植物种内多样性在何种程度上影响物种丰富的石灰岩草原的碳周转。此外，我们还将确定这是否通过与物种组成的相互作用发生，以及在何种程度上它是由土壤条件介导的，如物理和化学性质。自2004年以来，在一系列的中围生态系统中，已知遗传和物种组成的植物群落被组装和维持。这些中围生态系统还对它们施加了定义的土壤处理（存在裂缝和代表不同微环境的两种类似土壤类型），以模拟自然界中发生的变化。我们将测量土壤中一些重要物理组分的碳含量，以及土壤表面以CO2形式释放的碳。此外，我们将向植物提供13 CO2脉冲-一种天然且易于区分的碳同位素-使我们能够量化植物分配给土壤的碳量。这将使我们能够更机械地理解基因型多样性如何调节碳周转。这些数据将与过去项目中已经获得的个人生产力综合数据集一起进行分析，以全面了解种内多样性在调节碳周转方面的作用。这项工作将进一步加深我们对生物多样性的组成部分的理解，这些组成部分对碳周转很重要，而土壤因素可能会调节这一点。它也将提供一个基础，在此基础上制定保护战略的物种丰富的石灰岩草原，目标基因型，以及物种多样性

There is now a vast body of evidence showing that plant biodiversity affects the way in which ecosystems perform, such as the rate at which carbon is recycled or stored. But 'biodiversity' has many components, and we have recently shown that 'community composition', rather than the number of species or functional types of plant, is the key factor in regulating rates of carbon turnover. However, a largely ignored component of biodiversity is the variation at the level of the individual, that is, variation in genotypes of particular species or intraspecific diversity. We have shown that the number of individuals in a community has significant impacts on plant productivity by affecting competitive abilities of specific plant species. We have also shown that the number of genotypes per species has a significant effect on the root-fungal diversity, and other studies have also demonstrated that key plant traits related to carbon cycling are highly variable within species. These studies suggest that intraspecific diversity has potentially important consequences on carbon turnover. This project therefore seeks to discover the extent to which plant intraspecific diversity affects carbon turnover in species-rich limestone grassland. Moreover, we will additionally determine whether this occurs via interactions with species composition, and the extent to which it is mediated by soil conditions, such as physical and chemical properties. This will be achieved by using a series of mesocosms in which defined plant communities of known genetic and species composition have been assembled and maintained since 2004.These mesocosms also have imposed on them defined soil treatments (presence of crevices and two similar soil types representative of different microenvironments) to mimic the variation that occurs in nature. We will measure the carbon content of soil in a number of important physical fractions and release of carbon as CO2 from the soil surface. In addition, we will supply plants with a pulse of 13CO2 - a natural and easily distinguishable carbon isotope - to enable us to quantify the amount of carbon that plants allocate to soils. This will enable us to gain a more mechanistic understanding of how genotypic diversity regulates carbon turnover. The data will be analysed alongside the comprehensive datasets on productivity of individuals already obtained in past projects to gain a comprehensive picture of the role of intraspecific diversity in regulating carbon turnover. The work will further our understanding of the components of biodiversity that are important for carbon turnover, and the soil factors that may regulate this. It will also provide a basis on which to develop conservation strategies of species-rich limestone grassland that target genotypic, as well as species diversity