DISSERTATION RESEARCH: A Spatial Theory of Trophic Cascades in Omnivory Systems

确定影响其对扰动反应的群落特征是基础生态学和应用生态学的主要目标。当捕食者减少猎物时，就会发生营养级联，间接影响到较低营养水平的植物。该项目将数学模型及其预测与实验相结合，以确定为什么营养级联在不同的群落中有所不同。基于令人信服的初步数据，研究人员提出杂食动物——既吃动物也吃植物的生物——将稳定群落。这一假设将通过以混合细菌为资源、单细胞猎物物种、原生捕食者和原生杂食动物组成的实验食物网进行验证。研究人员将操纵实验群落的定殖率，并测量每个群落在这些操纵下的数学稳定性变化。模型将适合于时间序列数据，为杂食性食物网结构和稳定性变化的潜在原因提供新的见解。对该项目的支持将显著改善正在进行的博士论文项目，该项目将数学模型与实地实验相结合，表明殖民化率导致营养级联的一致变化。因此，对有前途的年轻科学家的培训将得到加强。该项目将涉及不同的本科生组合，他们将在生物学和数学的界面上进行研究。通过参与美国教育部RISE项目，研究人员将从当地社区大学转学到科学领域中代表性不足的优秀学生纳入研究实验室。这些学生将接受显微镜、实验设计、数学建模、统计分析和几种计算机编程环境的基本使用方面的培训。这项研究的结果将有助于遏制人类改变栖息地、生产具有商业价值的作物以及控制传播人类疾病的动物媒介。

Identifying the characteristics of communities that affect their responses to perturbations is a primary goal of both fundamental and applied ecology. Trophic cascades occur when predators reduce their prey, indirectly affecting lower trophic levels such as plants. This project combines mathematical models and their predictions with experiments to determine why trophic cascades vary across diverse communities. The investigators propose that omnivores - organisms that eat both animals and plants - will stabilize communities based on convincing preliminary data. This hypothesis will be tested using experimental food webs consisting of mixed bacteria as resources, a single-celled prey species, a protist predator, and a protist omnivore. The investigators will manipulate colonization rates across experimental communities and measure changes in the mathematical stability of each community in response to these manipulations. Models will be fit to time series of data to provide new insights into the causes underlying change in the structure and stability of omnivorous food webs. Support for this project will significantly improve an ongoing doctoral dissertation project that has combined mathematical models with field experiments to suggest that colonization rates result in consistent changes in trophic cascades. The training of a promising young scientist will be enhanced as a result. The project will involve a diverse assemblage of undergraduates who will perform research at the interface of biology and mathematics. Through participation in the United States Department of Education RISE program, the investigators integrate deserving students underrepresented in science fields into research labs when they transfer from local community colleges. These students will receive training in microscopy, experimental design, mathematical modeling, statistical analyses and basic usage of several computer programming environments. Results from the research will improve efforts to curb human alteration of habitats, production of commercially-valuable crops, and control of animal vectors that spread human disease.