Functional diversity among grass species: the role of photosynthetic pathway

当代生态学中尚未解决的主要问题之一是了解植物功能的多样性是如何产生的。这对解释全球生物多样性格局和预测气候变化的影响具有重要意义。在这个应用程序中，我们建议调查的因素，负责世界上的草种之间的生长性状的多样性，解决的问题，为什么不同的物种以不同的速度增长，并分配不同数量的增长根与叶。我们特别感兴趣的作用，已发挥了C3和C4光合途径之间的进化过渡。与C3类型相比，C4途径传统上被认为在炎热条件下促进植物的生长。光合作用途径是植物功能变化的主轴，它被用来解释生态系统结构对过去气候变化的响应，草种组成沿着全球气候梯度的周转，以及区域植物区系内物种的生态分类。然而，最近的工作已经挑战了这些长期存在的解释表明，生态适应温度和干旱，进化历史可能在解释大规模的地理和生态模式中发挥同样重要的作用。结合最近有趣的实验，这些新发现提出了关于C4光合作用与其他植物性状，生态学和进化历史相互作用影响植物生长的程度的问题。我们将通过采取比较筛选方法来研究约400种植物在一系列环境条件下的生长性状，从而解决这些主要问题。大物种样本的使用将使我们首次能够在一个统一的框架内揭示多种因素的相互作用。这种方法已经通过最近在一些领域的概念和方法的重大进展，并代表了生态和进化信息学领域的融合的一个重要步骤。

One of the major unresolved problems in contemporary ecology is to understand how diversity arises in plant function. This has important implications for interpreting global patterns of biodiversity and predicting the impacts of climate change. In this application, we propose to investigate the factors responsible for the diversity of growth traits among the world's grass species, addressing the question of why different species grow at different rates, and allocate different amounts of growth to roots vs leaves. We are particularly interested in the role that has been played by evolutionary transitions between the C3 and C4 photosynthetic pathways. The C4 pathway is classically thought to boost the growth of plants under hot conditions, in comparison with the C3 type. Photosynthetic pathway is a major axis of variation in plant function that has been invoked to explain significant changes in ecosystem structure in response to past episodes of climate change, the turnover of grass species composition along global climatic gradients, and the ecological sorting of species within regional floras. However, recent work has challenged these long-standing interpretations by demonstrating that ecological adaptation to temperature and drought, and evolutionary history may each play an equally important role in explaining large-scale biogeographical and ecological patterns. In combination with intriguing recent experiments, these new findings raise questions about the extent to which C4 photosynthesis interacts with other plant traits, ecology and evolutionary history to influence plant growth. We will address these major issues by taking a comparative screening approach to investigate the growth traits of ~400 species under a range of environmental conditions. The use of large species samples will allow us, for the first time, to unravel the interacting roles of multiple factors within a unified framework. This approach has been opened up through significant recent conceptual and methodological advances in a number of areas, and represents a major step in the fusion of the fields of ecological and evolutionary informatics.