A Comparative Ecophysiological Approach to Understanding Multi-Species Mycorrhizal Functioning

PIs对生物多样性和生态功能是如何联系在一起的理解还不是很清楚。树根的外生菌根（植物-真菌）关联为研究这种联系提供了一个理想的模型，因为外生菌根真菌(i)分布广泛，（ii）可能具有不同的获取营养的潜力，（iii）受到污染等人为压力的影响。该项目将首次详细研究外生菌根真菌的物种多样性和组成对树木幼苗生长和养分吸收的影响。PI将比较单次和多次感染外生菌根吸收必需营养素的能力，并确定这种能力是否受到菌根群落结构的影响。在这项工作的初始阶段，pi将证明他们有能力使用两种主要提出的方法，即：(i)测量培养和感染根尖上外生菌根菌丝体吸收磷的动力学；（ii）产生具有明确群落结构的1、2和4种外生菌根真菌组合的树木根系。在目前的预算下，PI将在吸收研究中只使用放射性32p，因为它可以使用现场设施进行测量。此外，由于PI无法购买气候控制生长柜，最初试验的结果可能显示出比原计划更大的变化。

Dighton 9723254 The PIs understanding of how biodiversity and ecological function are linked is not well understood. Ectomycorrhizal (plant-fungal) associations of tree roots provide an ideal model to study this linkage because ectomycorrhizal fungi are (i) widespread, (ii) may have different potentials to acquire nutrients and (iii) are affected by anthropogenic stresses, such as pollution. This project will be the first to detail effects of species diversity and composition of ectomycorrhizal fungi on tree seedlings growth and nutrient uptake. The PI will compare the ability of single and multiple infections of ectomycorrhizas to take up essential nutrients and determine whether this capacity is influences by mycorrhizal community structure. In this initial phase of the work the PIs' will prove their ability to use the two main proposed methodologies, that: (i) measuring the kinetics of P uptake into ectomycorrhizal mycelia in culture and on infected root tips; and (ii) production of tree root systems with defined community structures of 1, 2 and 4 species combinations of ectomycorrhizal fungi. Under the current budget, the PI will use only radioactive 32p in the uptake studies as it can be measured using on-site facilities Also because the PI can not purchase a climate-controlled growth cabinet, results from the initial trials may show a greater variability than originally intended.