Spatial ecosystems in varying environments: distribution, stucture and functioning

全球变化通过物种的增加和减少改变了生态系统的结构，并改变了生态系统的功能。全球变化首先影响个体生物，然后扩散到种群、物种和生态系统层面。由于错综复杂的生态相互作用，全球变化也间接影响物种。我的研究项目旨在了解这些复杂生态系统的结构如何受到环境变化的影响，以及它们的组织变化如何反过来影响它们的功能。我结合使用数学、计算机和生物模型来回答这个问题。科学家目前使用物种分布模型来理解全球变化对生物多样性的影响，而忽略了物种之间的相互作用。然而，生态系统中的生物是在不同的生态相互作用网络中组织起来的，因此在物种水平上的预测可能会导致错误的结论。该项目的具体目标是：i)了解复杂生态网络的结构如何在不断变化的环境中受到生物运动的影响；Ii)发展基于生态网络研究的新方法，以预测全球变化在生态系统层面的后果；iii)了解这种结构的改变如何影响复杂生态系统的功能，iv)用肉食性植物Sarracia purpurea中的食物网对这一理论进行实验验证。Sarracenia purpurea提供了一个有趣的生物学模型，因为它是一个完整的生态系统，有明确的边界，包括营养循环，可以很容易地在实验中进行操作。这一项目将有助于确定易受全球变化影响的物种特征，以及对生态系统功能产生最显著影响的物种特征。识别这些特征是对生态系统对全球变化反应的预测和一般科学的重要一步。

Global changes modify the structure of ecosystems with species addition and removal and it alters their functioning. Global changes affect first the organisms on an individual basis, and then propagate up to the population, species and ecosystem levels. Global changes also affect species indirectly because of an entangle web of ecological interactions. My research program aims at understanding how the structure of these complex ecosystems is affected by environmental changes, and how in return this alteration of their organization affects their functioning. I use in combination mathematical, computer and biological models to answer this question. Scientists currently use species distribution models to undertand the effect of global changes on biodiversity that neglect the interactions between species. Organisms in an ecosystem are however organized in diverse networks of ecological interactions and consequently predictions at the species level might lead to erroneous conclusions. The specific objectives of this project are: i) understand how the structure of complex ecological networks is affected by the movement of organisms in a changing environment; ii) develop novel methodologies based on the study of ecological networks to predict the ecosystem-level consequences of global changes; iii) understand how the alteration of this structure affects the functioning of complex ecosystems and iv) test experimentally this theory with the food web contained in the carnivorous plant Sarracia purpurea. The Sarracenia purpurea provides an interesting biological model because it is a complete ecosystem with well defined boundaries, that includes nutrient recycling and that could be easily manipulated experimentally. This project will allow the identification of species characteristics making them vulnerable to global changes and the characteristics associated with the most pronounced effects on ecosystem functioning. Identification of these characteristics is an essential step toward a predictive and general science of ecosystem's response to global changes.