Linking seeds and seedlings: Models and mechanisms.

植物物种在许多方面都有差异，例如它们的种子大小，它们生长的速度以及它们对各种环境压力（干旱，被吃掉等）的反应。了解植物生物学的这些不同方面是否以及如何联系起来，对于理解为什么某些物种出现在特定的栖息地以及预测环境变化的可能影响非常重要。在大多数植物和动物中，较大的生物体往往生长较慢，生存得更好。当比较不同大小的物种时，这有重要的后果，因为我们想知道观察到的差异，比如生长，是否仅仅是大小的结果，或者生物学的其他方面是否很重要。在这项研究中，我们将使用实验来探索生长和生存与大小的关系，从而使我们能够确定物种之间的差异是否仅仅是大小的结果。利用实验结果，我们将能够确定在一个共同的大小，快速生长的物种是否遭受死亡率增加，以及这是如何在栖息地之间变化的。这些信息与数学模型相结合，使我们能够预测最佳种子大小，以及我们期望物种在田间生产的种子大小。目前，对物种产生非常不同的种子大小的理解非常有限，这使得这项工作特别令人兴奋。所有的数学模型都有假设，因此我们将产生更通用的模型，结合生物学的现实方面，例如在竞争资源时，较大的幼苗将比较小的幼苗更好，并探索这如何改变模型的预测。

Plant species differ in many ways, for example their seed sizes, how fast they grow, and their responses to various environmental stresses (drought, being eaten etc). Understanding if and how these different aspects of plant biology are linked is important for understanding why some species occur in specific habitats, and also for predicting the possible effects of environmental change. In most plants and animals larger organisms tend to be slower growing and survive better. This has important consequences when comparing species of different sizes, because we would like to know if the observed differences in, say growth, are simply a consequence of size, or if other aspects of the biology are important. In this research we will use experiments to explore how growth and survival are related to size, so allowing us to determine whether differences between species are simply a consequence of their sizes or not. Using the experimental results we will then be able to determine whether at a common size, fast growing species suffer increased mortality, and how this varies between habitats. This information when combined with mathematical models allow us to predict the best seed size, and so the one we expect species to produce in the field. Currently the understanding of why species produce very different seed sizes is very limited, making this a particularly exciting aspect of the work. All mathematical models make assumptions and so we will produce more general models incorporating realistic aspects of biology, for example larger seedling will be better than small ones when competing for resources, and explore how this alters the predictions of the models.