A Comparative Ecophysiological Approach to Understanding Multi-Species Mycorrhizal Functioning

Dighton 9723254 PI对生物多样性和生态功能如何联系的理解还没有得到很好的理解。外生菌根（植物-真菌）协会的树根提供了一个理想的模型来研究这种联系，因为外生菌根真菌是（i）广泛分布，（ii）可能有不同的潜力，以获得营养物质和（iii）受到人为压力，如污染。 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苗生长和养分吸收的影响。PI将比较外生菌根单次和多次感染吸收必需营养物质的能力，并确定这种能力是否受到菌根群落结构的影响。 在这一工作的初始阶段，PI将证明他们有能力使用两种主要的拟议方法，即：（i）测量培养物和受感染的根尖上的外生菌根菌丝体吸收磷的动力学;（ii）生产具有1，2和4种外生菌根真菌组合的确定群落结构的树根系统。根据目前的预算，PI将在摄取研究中仅使用放射性32 p，因为它可以使用现场设施进行测量。此外，由于PI无法购买气候控制的生长柜，初始试验的结果可能显示出比最初预期更大的变异性。

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.