Mechanisms of Below-Ground Resource Acquisition in Plants: Linking Form and Function

本研究的目的是了解 不同植物细根结构的差异， 动态响应营养斑块影响他们的能力， 获取土壤资源，特别是氮。 整体 假设细根形态（长度， 宽度，根毛的产生）和产生（出生，死亡， 和伸长率）将决定物种 遇到和利用不同空间和时间的土壤资源 (i.e.的能力）。 以前的研究表明， 一年生和多年生植物对土壤反应的差异 营养素 这导致了一种假设， 一年生植物的多年生植物在演替领域可能是部分 由于随着时间的推移， 一年生植物和多年生植物在寻找和 利用这些补丁。 特别令人感兴趣的是 对营养斑块的反应，将由 测量物种的人口反应。 几个具体的假设将在温室和 田间试验 通过改变氮的分布， 以~（15）N为示踪剂，研究了细根与根系的关系 形态学和动力学以及资源获取将是 测定了 细根动态（分枝、生长、生育和 死亡率）将通过视频技术进行现场测量。 这 技术允许单个根对养分的反应， 斑块要遵循和有关的物种差异， 地下形态、生长和获得土壤的能力 资源 这些研究的结果将有助于 发展对土壤资源更机械的理解 植物的收购，并更好地了解如何 对资源的竞争影响着物种的分布， 陆生植物群落

The objective of the proposed research is to understand how differences among plant species in fine root structure and dynamics in response to nutrient patches affects their ability to acquire soil resources particularly nitrogen. The overall hypothesis is that differences in fine root morphology (length, width, production of root hairs) and production (birth, death, and elongation rate) will determine the rate at which species can encounter and exploit soil resources that vary in space and time (i.e. their foraging ability). Previous work suggests there are difference among annuals and perennials in response to soil nutrients. this has led to the hypothesis that the replacement of annuals by perennials in successional fields may be partially due to the increased patchiness in soil resources over time and difference in the abilities of annuals and perennials to find and exploit these patches. Of particular interest is the timing of responses to nutrient patches which will be determined by measuring the demographic response of species. Several specific hypothesis will be tested in greenhouse and field experiments. By varying the distributions of nitrogen, and using 15 N as a tracer, the relationship between fine root morphology and dynamics and resource acquisition will be measured. Fine root dynamics (branching, growth, birth and mortality) will be measured in situ with video technology. This technology allows the response of individual roots to nutrient patches to be followed and related to species differences in below-ground morphology, growth, and ability to acquire soil resources. The results of these studies will contribute to the development of a more mechanistic understanding of soil resource acquisition by plants and to a better understanding of how competition for resources affects species distributions in terrestrial plant communities.