REU: Mechanisms of Below-ground Competition in Plants: Linking Form and Function

这项研究将研究植物细根系统的形态和人口统计学如何能够获得两种有限的土壤资源：水和氮。植物改变细根形态(长度、宽度、分枝模式、根毛的产生)和人口统计学(出生、死亡和伸长率)的能力被认为影响随后遇到和开发土壤资源的速度。总体假设是，物种在细根形态和人口统计学上的差异决定了它们获取地下资源的能力，从而竞争这些资源。遇到和利用在空间和时间上不同的资源补丁的能力必须与根的形态和动态联系起来。几个具体的假设将在一系列温室实验中得到验证。将使用微型加速器的原位视频成像来测量细根动态，并使用生命表和投影矩阵进行总结。通过改变水分和氮素的有效性和空间分布，并使用15C作为示踪剂，我们将能够测量细根形态和动态与资源获取之间的关系。这项研究是新颖和创新的，因为它利用新技术来理解资源可用性如何驱动细根人口统计。到目前为止，几乎所有的生态学研究要么忽略了细根(一个主要的碳汇)，要么在一次或一系列静态观测中对其进行了量化。该项目将在更机械化地理解陆地植物对土壤资源的竞争方面取得重大进展。

This research will examine how the morphology and demography of the fine root system of plants enables the acquisition of two limiting soil resources: water and nitrogen. The ability of plants to alter fine root morphology (length, width, branching pattern, production of root hairs) and demography (birth, death, and elongation rate) is thought to affect the rate at which then encounter and exploit soil resources. The overall hypothesis is that species differences in fine root morphology and demography regulate their ability to acquire below.ground resources and therefore compete for these resources. The ability to encounterand exploit resource patches that vary in space and time must be linked to root morphology and dynamics. Several specific hypotheses will be tested in a series of greenhouse experiments. Fine root dynamics will be measured using in situ video imaging of minirhizotrons and summarized using life-tables and projection matrices. By varying the availability and spatial distribution of water and nitrogen, and by using 15C as a tracer, we will be able to measure the relationship between fine and root morphology and dynamics and resource acquisition. This research is novel and innovative because it utilizes new technology to understand how resource availability drives fine root demography. Until now, virtually all ecological investigations have either ignored fine roots (a major carbon sink), or quantified them in one or aseries of static observations. This project will make significant progress toward the development of a more mechanistic understanding of competition for soil resources in terrestrial plants.