Population Dynamics in a Heterogenous Environment: The Effect of Variance in Plant Quality on Herbivore Populations in Time and Space

0089570. 诺拉·安德伍德。相当多的生态学研究已经记录了食草动物对其食物的平均特征做出反应的方式；然而，人们对食物质量的变化如何影响食草动物个体或食草动物种群知之甚少。拟议的研究将量化植物之间的质量差异影响个体运动的方式，以及昆虫食草动物的种群动态。一个空间显式模型将用于研究草食动物运动如何影响植物质量变化和种群动态在时间和空间上的相互作用。然后，该模型将为理解表型、基因型或植物物种之间的质量差异如何影响昆虫人口统计学提供一个框架。田间试验将检验草莓种群遗传质量的可变性如何影响草莓蚜虫的运动和种群动态。短期实验将量化单个蚜虫的运动与饲料质量种群水平差异的关系。较长期的实验将把蚜虫种群对食物质量的不同变异的动态反应联系起来，从单一栽培植物的特征到两到六种不同基因型混合栽培的特征。这种方法将有助于对一种假设进行批判性审查，即农业混合植物品种（基因型）比单一栽培支持更低的害虫种群密度。最后，将植物质量的遗传变异与食草动物的人口统计学联系起来，为理解植物-食草动物的动态提供了一个重要的生态和进化观点的综合。

0089570. Nora Underwood. Considerable ecological research has documented the way in which herbivores respond to mean characteristics of their food; however, little is known about the way in which variability in food quality affects individual herbivores or populations of herbivores. The proposed research will quantify the way in which variance in quality among plants affects the movement of individuals, as well as the population dynamics of insect herbivores. A spatially explicit model will be used to examine how herbivore movement influences the interaction between the variance in plant quality and population dynamics in time and space. This model will then provide a framework for understanding how variance in quality among phenotypes, genotypes, or species of plants affects insect demographics.Field experiments will examine how variability in the genetically based quality of strawberry populations affects the movements and population dynamics of the strawberry aphid. Short-term experiments will quantify the way in which the movement of individual aphids is related to population-level variance in forage quality. Longer-term experiments will relate the dynamical response of aphid populations to different kinds of variance in food quality, ranging from that characteristic of plant monocultures to that characteristic of mixed cultures of two to six different genotypes. This approach will facilitate a critical examination of the hypothesis that agricultural mixtures of plant varieties (genotypes) support lower population densities of pests than will monocultures. Finally, linking the genetic variance in plant quality to the demographics of herbivores provides a critical synthesis of ecological and evolutionary perspectives in understanding plant-herbivore dynamics.