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，关于食物质量的变化如何影响个体食草动物或食草动物种群的方式，人们知之甚少。这项拟议的研究将量化植物之间质量差异对个体运动的影响方式，以及昆虫食草动物的种群动态。一个空间上明确的模型将被用来研究食草动物的运动如何影响植物质量的变化和种群动态在时间和空间上的相互作用。这个模型将为理解表型、基因类型或植物物种之间的质量差异如何影响昆虫种群数量提供一个框架。田间实验将研究草莓种群遗传质量的差异如何影响草莓蚜虫的迁徙和种群动态。短期实验将量化个体蚜虫移动与饲草质量种群水平差异之间的关系。更长期的实验将把蚜虫种群对食物质量不同种类差异的动态反应联系起来，从植物单一培养的特征到两到六个不同基因类型的混合培养的特征。这种方法将有助于对农业混合植物品种(基因类型)支持比单一栽培更低的害虫种群密度这一假设进行关键检验。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，提供了理解植物-食草动物动态的生态和进化观点的关键综合。

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.