Chemical Hydrology of Vascular Plant Growth: Role of Root-Fungus Associations

维管植物生长的化学水文学：根真菌协会的作用

• 批准号: 0312011
• 负责人: C. Kent Keller
• 金额: $ 24.97万
• 依托单位: Washington State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-15 至 2007-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0312011&HistoricalAwards=false
• 关键词: Chemical; Hydrology; Vascular; Plant; Growth

The dissolved chemical load of runoff - i.e. discharge of dissolved mass from terrestrial environments to streams, groundwater and the oceans - is important for its relationship to nutrient retention and loss in ecosystems, quality of aquatic and marine coastal habitats, and long-term climate control exerted by the ocean-atmosphere system. Vascular plants promote dissolution of primary minerals, or chemical weathering, to meet their nutritional requirements for growth; this plant-driven weathering has long been understood to affect the chemistry of soil water and the chemical loading of runoff. This research will experimentally investigate the mechanisms by which rooted plant growth affects soil water chemistry and the hydrologic loss, in runoff, of mineral-derived elements from watersheds. Previous work by us on experimental ecosystems at Hubbard Brook indicates that pine tree growth reduces both soil-water concentrations of base cations in the rooting zone, and the discharge of these cations in drainage water, relative to controls. This research is designed to investigate how, and under what conditions, mineral-to-root chemical transport is isolated from soil water and "protected" from hydrologic loss. It is hypothesized that this phenomenon is a feature of root-to-mineral attachment which occurs during plant growth. It is specifically hypothesized that ectomycorrhizal fungi and their hyphal networks function as root-to-mineral conduits which facilitate the hydrochemical control observed by us at Hubbard Brook. The hypothesis will be tested by replicated growth experiments in the laboratory and in greenhouses. The experiments will isolate fungal and fungi-root-plant effects on solution chemistry and loss in drainage from hydrologically, chemically and ecologically simple systems. Additionally, base cations will be tracked from their sources at mineral surfaces into fungal and plant tissue and into drainage. Broader impacts of this research include participation of high school and undergraduate students, particularly women, in data collection and interpretation via coursework and part-time jobs; dissemination of findings via interdisciplinary forums and the world wide web; and improvement of our understanding of long-term ecosystem sustainability and controls on the partitioning of sequestered atmospheric CO2 into short-term and long-term storage.

径流的溶解化学负荷----即溶解物质从陆地环境排放到溪流、地下水和海洋----对于其与生态系统中营养物的保持和损失、水生和海洋沿海生境的质量以及海洋-大气系统所施加的长期气候控制的关系十分重要。 维管植物促进原生矿物质的溶解或化学风化，以满足其生长的营养需求;这种植物驱动的风化长期以来被认为会影响土壤水的化学性质和径流的化学负荷。本研究将通过实验研究生根植物生长影响土壤水化学和水文损失的机制，径流中，来自流域的矿物质衍生元素。我们以前的工作在哈伯德溪实验生态系统表明，松树的生长减少土壤水浓度的基础阳离子在生根区，这些阳离子在排水中的排放，相对于控制。本研究的目的是调查如何，在什么条件下，矿物根的化学运输是从土壤水隔离和“保护”水文损失。 据推测，这一现象是一个特点，根到矿物的附着过程中发生的植物生长。特别假设外生菌根真菌和它们的菌丝网络作为根到矿物质的管道，这有利于我们在哈伯德溪观察到的水化学控制。这一假设将在实验室和温室中通过重复的生长实验进行检验。 这些实验将从水文、化学和生态简单的系统中分离出真菌和真菌根植物对溶液化学和排水损失的影响。此外，碱阳离子将从矿物表面的来源进入真菌和植物组织并进入排水系统。 这项研究的更广泛的影响包括高中和大学生，特别是女性，通过课程和兼职工作参与数据收集和解释;通过跨学科论坛和万维网传播研究结果;以及提高我们对长期生态系统可持续性的理解和对隔离的大气CO2分为短期和长期储存的控制。