CAREER: Spatial network structure and food web stability across a productivity gradient.

许多对野生动物和人类福祉很重要的环境在整个景观中分布不均。这些“斑驳”环境的例子包括湿地等自然栖息地和农田等人类管理的栖息地。这个项目将测试这样一种观点，即不同物种（生物多样性）的数量取决于动物在不同栖息地之间移动的能力，这些栖息地出现的地方，以及每个斑块中可用的食物量。了解是什么决定了生物多样性是很重要的，因为它使人们能够预测和管理特别是多样化的，往往是脆弱的栖息地。因为在自然地区严格测试生物多样性的决定因素实际上是不可能的，所以这个项目将在实验室进行。研究人员将为生活在水中的非常小的动物创造微型的、斑驳的世界，以研究现实世界中更大范围的动物会发生什么。实验将集中在物种的数量、它们的扩散能力和小容器中可供它们使用的食物数量之间的关系。将建立一个复杂的模型来帮助分析数据，并将结果扩展到不同的动物和不同类型的栖息地斑块。实验所的实验亦会应用于教学及外展活动，让小学生及教师透过亲身体验，学习科学方法及生态概念。学生和老师都将帮助设计和实施实验，直接为科学过程做出贡献。研究人员将通过实验测试生态系统的一个共同特征——在不规则分布的栖息地之间分散——是否会影响基本生态单元——食物网的稳定性。研究将包括实验和理论组成部分。使用原生生物微观世界进行的实验将验证网络理论提出的假设：(1)通过随机结构的分散网络连接的食物网将比常规网络连接的食物网表现出更大的空间异步性和网络范围的稳定性；(2)分散的影响将在资源生产力的梯度上变化，因为这一因素已知会改变食物网的稳定性。实验将与机制模型相结合，将项目发现的普遍性扩展到更广泛的背景下，并推进一般食物网理论。本研究还将利用原生生物微观世界的可追溯性，在本科生态学课程中提供探究式的课程内容和学生研究项目。来自目前在科学领域代表性不足的群体的学生将被招募，并在实验设计、数据收集、分析和演示方面得到指导。外展活动将把公立学校的教师带到研究者的实验室，并将生态研究经验转化为符合下一代科学标准的课程计划。

Many environments that are important for wildlife and human well-being are spread unevenly across the landscape. Examples of these "patchy" environments include natural habitats like wetlands and human-managed habitats like agricultural fields. This project will test the idea that the number of different species (biodiversity) that can live in patches of habitat depends on the animals' ability to move between patches, the places where those patches occur, and the amount of food available in each patch. Understanding what determines biodiversity is important because it allows one to predict and manage especially diverse, often vulnerable, patches of habitat. Because it is practically impossible to rigorously test the determinants of biodiversity in natural areas, this project will take place in the laboratory. Researchers will create miniature, patchy worlds of very small animals that live in water to study what happens on much larger scales to animals in the real world. Experiments will focus on the relationship between the number of species, their dispersal abilities, and the amount of food available to them in small containers of water. A complicated model will be built to help analyze the data and extend the results to different animals and different types of habitat patches. The laboratory experiments will also be used in teaching and outreach activities to provide opportunities for grade-school students and teachers to learn scientific methods and ecological concepts through hands-on experiences. Both students and teachers will help design and carry out experiments, contributing directly to the scientific process.The investigator will experimentally test whether a common feature of ecological systems -- dispersal among irregularly distributed habitats -- affects the stability of a fundamental ecological unit, the food web. Research will include experimental and theoretical components. Experiments conducted using protist microcosms will test hypotheses arising from network theory that: (1) food webs connected through randomly structured dispersal networks will show greater spatial asynchrony and network-wide stability than those connected in regular networks and (2) effects of dispersal will vary across a gradient in resource productivity, as this factor is known to alter food web stability. Experiments will be integrated with mechanistic models, extending the generality of project findings to broader contexts and advancing general food web theory. The research will also leverage the tractability of protist microcosms to provide inquiry-based curriculum content and student research projects in an undergraduate ecology course. Students from groups currently underrepresented in science will be recruited and mentored in experimental design, data collection, analysis and presentation. Outreach activities will bring public school teachers into the investigator's laboratory and translate ecological research experiences into lesson plans aligned to Next Generation Science Standards.