Eco-evolutionary dynamics of communities in changing environments

当前环境变化的速度对物种构成了严重的挑战。人为引起的环境变化包括二氧化碳等温室气体的增加、气温上升、农田化肥径流增加以及入侵物种的引入。虽然环境一直在变化，物种在地质时间尺度上一直在更替，但目前的变化速度和所涉及的众多因素正在威胁物种和生态群落的持久性，这是一种具体的危险。我的研究项目的目标是了解自然生态系统中的物种是否以及如何应对这种变化因素的混合物。特别令人感兴趣的问题是，进化是否能够发生得足够快，以便受威胁的物种能够适应新的环境，并从灭绝中拯救出来。我将实验和理论相结合，在三个不同的系统中研究生态和进化对环境变化的反应：一个湖泊系统，浮游生物受到二氧化碳、温度、酸度和主要营养物质同时变化的挑战；以鱼类为基础的系统，鱼类需要应对和适应寄生虫；以及一个模拟复杂生态系统行为的数学模型系统。所有系统都有相同的目标，即评估生态和进化如何促进生物体适应不断变化的环境；但它们产生了不同层次的见解。湖泊系统将为浮游生物的反应提供信息，浮游生物通过光合作用产生了全球一半的初级生物量。设计鱼-寄生虫系统的目的是提供有关疾病传播的一般见解，以及进化出的抵抗力如何有助于阻止疾病传播。数学模型系统将帮助我们认识到受到环境变化威胁的生态群落，并评估进化适应是否可以拯救它们。从基础科学的角度来看，这项研究将促进我们对复杂群落中生态和进化动力学的认识和理解。但这项研究对加拿大人和全球人口也有应用价值，因为它将使我们能够预测人类引起的环境变化对地球生物群的影响，包括人类本身。

The current pace of environmental change poses serious challenges to species. Human-induced environmental changes include increase of greenhouse gases such as CO2, rising temperature, increasing runoff of fertilizers from agricultural fields and the introduction of invasive species. Although the environment has always been changing and species have always been turning over on geological time scales, there is a concrete danger that the current pace of change and the multitude of factors involved are threatening the persistence of species and ecological communities. The goal of my research program is to understand whether and how the species in natural ecosystems can cope with this cocktail of changing factors. Of particular interest is the question whether evolution can happen fast enough so that threatened species can adapt to the new conditions and be rescued from extinction. I combine experimental and theoretical approaches and study the ecological and evolutionary responses to the changing environment in three different systems: a lake system in which plankton is challenged with the simultaneous changes of CO2, temperature, acidity and major nutrients; a fish-based system where the fish need to cope with and adapt to parasites; and a mathematical model system that simulates the behaviour of complex ecosystems. All systems have the same goal to evaluate how ecology and evolution contribute to adaptation of organisms to the changing environment; but they produce insights at different levels. The lake system will inform about the response of plankton organisms, which - through photosynthesis - produce half of the global primary biomass. The fish-parasite system is designed to provide general insights into the spread of diseases and how evolved resistance can help impede their spread. The mathematical model system will help us to recognize ecological communities that are threatened by environmental change and to assess whether evolutionary adaptation may rescue them. From a fundamental science point of view, the research will advance our knowledge and understanding of ecological and evolutionary dynamics in complex communities. But the research is also of applied value to Canadians and the global human population because it will allow us to make predictions about the impact of human-induced environmental change on the Earth's biota, including humans themselves.