Ecophysiological Roles of Plants, Mycorrhizae, and Soil Microbes in Early Spring Nitrogen Dynamics

PIS将研究在科罗拉多州阿尔卑斯山积雪融化期间，基本植物营养氮(N)如何从土壤微生物转移到植物身上。PI初步研究表明，在积雪融化期间，土壤微生物的数量有所下降，而且这种下降与土壤中N的增加相一致。令人惊讶的是，这种氮的脉冲几乎完全保留在系统内，不会污染下游水源。PI将研究与植物根部相关的植物和真菌如何与土壤微生物竞争积雪融化期间释放的氮的机制。PIS还将调查是什么导致了积雪融化期间土壤微生物的下降。这些研究将有助于我们理解氮是如何在高山系统中被保留的。这一信息很重要，因为N的输入(来自汽车尾气和发电厂排放)正在增加，如果N从高山地区冲入下游饮用水供应中，它就会成为污染物。

The PIs will study how the essential plant nutrient nitrogen (N) is transferred from soil microorganisms to plants during snow melt in the Colorado alpine. The PIs preliminary studies show that there is a decline in the population of soil microorganisms during snow melt and that this decline coincides with an increase in N in the soil. Surprisingly this pulse of N is almost entirely retained within the system and does not pollute downstream water sources. The PIs will study the mechanics of how plants and fungi associated with plant roots compete with soil microorganisms for the N released during snow melt. The PIs will also investigate what causes the decline of soil microorganisms during snow melt. These studies will help us to understand how N is retained in alpine systems. This information is important since N inputs (from car exhaust and power plant emissions) are increasing and N acts as a pollutant if it is flushed from alpine areas into downstream drinking water supplies.