Mechanisms of Plant-Herbivore Interactions

植物与草食动物相互作用的机制

• 批准号: 9007125
• 负责人: David Tilman
• 金额: $ 18.49万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-07-01 至 1993-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9007125&HistoricalAwards=false
• 关键词: Mechanisms; Plant; Herbivore; Interactions

The P.I.'s intend to explore the mechanisms of interaction among terrestrial plants and their herbivores, including both direct interactions (e.g. herbivores consume plants) and indirect interactions (e.g. herbivores may affect the outcome of plant competition by increasing soil nutrient concentration). previous studies of old field grasses and herbs and their major herbivores, grasshoppers, at their study site in central Minnesota indicate that (1) plants are limited by and compete for soil nitrogen, (2) grasshopper reduce plant abundance and affect plant species composition, and (3) grasshoppers are limited by and compete for plant food. Based on these studies, the investigators propose three experiments to show how these interactions link together: (1) garden experiments in which the effects of different plants on soil nitrogen, plants on other plants, grasshoppers on plants, grasshoppers on nitrogen, and grasshoppers on other grasshoppers will be measured separately and in combination on plots where soil nutrients, plant species composition, and grasshopper densities will be controlled, (2) field experiments in which densities of six grasshopper species will be manipulated to look at these same potential effects in a natural community, and (3) laboratory feeding experiments in which grasshoppers will be fed different plant species and their preference and physiological responses measured. These experiments will measure the mechanisms and strength of direct and indirect plant - herbivore interactions under controlled conditions, determine the role of herbivore diet selection in these interactions, and determine the importance of these interactions in a real community containing the same plant and grasshopper species. This study may be the first to address all three goals in a single, relatively simple, system. The results will provide a foundation for predicting the outcome of these interactions and consequently, the structure of plant and herbivore communities. //

侦探旨在探索陆生植物与其食草动物相互作用的机制，包括直接相互作用（如食草动物消耗植物）和间接相互作用（如食草动物可能通过增加土壤养分浓度来影响植物竞争的结果）。先前在明尼苏达州中部的研究地点对古老的草地和草本植物及其主要食草动物蚱蜢的研究表明：(1)植物受到土壤氮的限制并竞争；(2)蚱蜢减少了植物的丰度并影响了植物的物种组成；(3)蚱蜢受到植物食物的限制并竞争。基于这些研究，研究人员提出了三个实验来展示这些相互作用是如何联系在一起的：(1)在控制土壤养分、植物种类组成和蚱蜢密度的地块上，分别和组合测量不同植物对土壤氮的影响、植物对其他植物的影响、蚱蜢对植物的影响、蚱蜢对其他蚱蜢的影响；(2)实地实验，控制六种蚱蜢的密度，以观察在自然群落中同样的潜在影响；(3)实验室取食实验，以不同的植物种类为食，测量蚱蜢的偏好和生理反应。这些实验将测量受控条件下植物-食草动物直接和间接相互作用的机制和强度，确定食草动物饮食选择在这些相互作用中的作用，并确定这些相互作用在包含相同植物和蚱蜢物种的真实群落中的重要性。这项研究可能是第一个在一个相对简单的系统中解决这三个目标的研究。研究结果将为预测这些相互作用的结果，从而预测植物和食草动物群落的结构提供基础。//