Collaborative Research: A Role for Insect Herbivores in Plant Population Growth and Regulation: Density Manipulations and Demographic Models

了解控制植物种群大小的因素对我们对自然的基本认识和制定控制杂草和入侵植物的方法具有重要意义。生态学家同意，植物常常因为与其他植物物种争夺资源而受到限制。然而，关于以植物为食的昆虫（食草动物）在控制植物种群中有多重要仍有争议。先前对食草动物影响的测试只考虑了在低密度条件下对植物繁殖的影响，而没有考虑食草动物的影响如何随着植物密度的变化而变化。本研究将采用田间实验结合数学模型来确定在一定植物密度范围内，食草昆虫对杂草植物种群增长的影响。入侵植物和杂草在美国造成了巨大的经济和环境成本。利用生物防治剂，特别是食草昆虫防治这些植物已成为人们关注的焦点。这种方法假设食草动物强烈影响植物种群。该项目将为这一假设提供迄今为止最完整的测试。它还将帮助培养新的科学家，包括学生作为助手（学习研究技术、数据分析和计算机编程）和独立研究人员（学习设计研究和展示结果）。

Knowing the factors that control plant population size is important for our basic understanding of nature and for developing methods for controlling weedy and invasive plants. Ecologists agree that plants are often limited by competition with other plant species for resources. However there is debate about how important insects that eat plants (herbivores) are in controlling plant populations. Previous tests of the influence of herbivores have considered only effects on plant reproduction under low-density conditions and have not accounted for how the influence of herbivores changes with plant density. This study will use field experiments coupled with mathematical models to determine the influence of insect herbivores on the population growth of a weedy plant over a range of plant densities. Invasive and weedy plants impose enormous economic and environmental costs in the USA. Much attention has focused on using bio-control agents, particularly insect herbivores, to control these plants. This approach assumes that herbivores strongly affect plant populations. This project will provide the most complete test of this assumption to date. It will also help train new scientists, involving students as assistants (learning research techniques, data analysis and computer programming), and as independent researchers (learning to design studies, and present results).