Disertation Research: Nitrogen-Plant-Insect Interactions: Integrating Via a Net Effects Approach

小行星9423316科尔曼 众所周知，氮肥既能提高植物生产力，又能减少植食性昆虫的危害。某些水平和比率 的 受精可能会产生负面影响 影响 通过增加昆虫的破坏量来提高植物的生产力。 这项研究将研究两种食草昆虫的净影响， 两种植物的生长环境 不同的施肥制度。 它是专门设计来了解受精和昆虫植食性的后果 对植物生产力的影响。 两个经济和生态上重要的树种（橡树和棉白杨）与对比的生活史性状和两个经济上有害的昆虫草食动物物种的主题。 施肥实验将在种植的田间小区和温室中进行，用于对照和比较目的。 每个树种的样品将暴露于不同的施肥时间表，在存在和不存在昆虫食草动物，植物生长，组织化学和食草动物的性能和影响将被测量。 这项研究的结果应该提高对植物生产力影响的理解 施肥水平和添加率，在存在和不存在昆虫食草动物。它们将揭示施肥对植物生长的积极影响和施肥通过刺激昆虫取食植物的负面影响之间何时发生权衡。 长期结果 可以 包括制订 优化植物净生产力的施肥方法，同时减少肥料和农药的需求。

9423316 Coleman Nitrogen fertilization is well known to both increase plant productivity and insect herbivore damage. Certain levels and rates of fertilization may negatively affect plant productivity by increasing the amount of damage by insects. This research will examine the net impact of two insect herbivores on two plant species grown under various fertilization regimes. It is designed specifically to understand the consequences of fertilization and insect herbivory in combination on plant productivity. Two economically and ecologically important tree species (oak and cottonwood) with contrasting life history traits and two economically detrimental insect herbivore species are the subjects. Fertilization experiments will be carried out in both a planted field plot and, for control and comparison purposes, in a greenhouse. Samples of each tree species will be exposed to differing fertilization schedules in the presence and absence of insect herbivores, and effects on plant growth, tissue chemistry, and herbivore performance will be measured. The results of this study should improve understanding of the impact on plant productivity of fertilization levels and rates of addition, in the presence and absence of insect herbivores. They will reveal when tradeoffs occur between positive effects of fertilization on plant growth and negative effects of fertilization through stimulation of insect feeding on plants. The long term result may include the formulation of fertilization practices that optimize net productivity of plants, yet reduce fertilizer and pesticide requirements.