Resource Acquisition, Allometry, and Growth of Individuals within Competing Plant Populations

竞争在植物生态学和进化中的核心作用是一个被广泛接受的概念。然而，我们对竞争机制的理解非常有限，部分原因是它没有强有力的机制基础。本项目提出了一种新的、多层次的植物竞争研究方法。该方法将描述资源竞争生理方面特征的新方法与传统的增长分析和人口统计学技术相结合。本研究选择的系统是在实验建立的两种桦树（白桦和白桦）的田间单一栽培中进行竞争相互作用，这两种桦树对光、水和营养的需求不同。资源吸收和林分发展将监测两年。第三年将致力于处理植物和土壤样本以及建模和综合数据。研究结果将使我们能够评估林分发育不同阶段对光和养分竞争的程度和相对重要性，并对目前关于植物间资源竞争的一些假设进行实证检验。该研究将是弥补现有的植物竞争和林分发育现象模型与竞争生理机制之间差距的重要一步。

9630397 Bazzaz The central role of competition in the ecology and evolution of plant is a widely accepted concept. Yet, our understanding of the mechanisms of competition is quit limited, in part because it does not have a strong mechanistic basis. This project proposes a novel, multi- level approach to the study of plant competition. The approach combines a new method for characterizing physiological aspects of resource competition with traditional growth analyses and demographic techniques. The system chosen for the study is competitive interactions in experimentally established field monocultures of two birch species, (Betula alleghaniensis and B. populifolia), that differ in their requirements for light, water and nutrients. Resource uptake and stand development will be monitored for two years. A third year will be devoted to processing plant and soil samples and to modeling and synthesizing data. The results will allow us to assess the magnitude and relative importance of competition for light and nutrients at various stages of stand development, and to empirically test a number of current hypotheses regarding resource competition among plants. The research will be an important step in bridging the gap between well-developed phenomenological models of plant competition and stand development, and the physiological mechanisms of competition.