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于我们对自然界的基本了解以及开发控制杂草和入侵植物的方法都很重要。生态学家一致认为，植物往往受到与其他植物物种争夺资源的限制。然而，对于以植物为食的昆虫(食草动物)在控制植物种群方面有多重要，还存在争议。以前对食草动物影响的测试只考虑了低密度条件下对植物繁殖的影响，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。这项研究将使用田间实验和数学模型相结合的方法来确定昆虫食草动物对杂草植物在一定密度范围内种群增长的影响。入侵和杂草植物在美国造成了巨大的经济和环境成本。人们的注意力主要集中在使用生防剂，特别是昆虫食草动物来控制这些植物。这种方法假定食草动物强烈影响植物种群。这个项目将提供迄今为止对这一假设的最完整的测试。它还将帮助培训新的科学家，让学生担任助理(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).