Nitrogen Storage in Alpine Plants

这项研究验证了储存氮超过 冬季是高山植物重要的适应期。 高山 环境的特点是：（1）生长季节短，（2） 土壤温度低; 3）氮素有效性低。 通过 利用在一个生长季节储存的氮，植物可以开始 即使土壤太冷， 从土壤中获取氮素。 这可能会让他们 最大限度地利用高山生长季节短， 在霜冻的危险到来之前， 太好了 调查人员将确定植物何时使用 当植物能够吸收氮时， 从土壤中。 如果他们发现植物在 它们可以在春天获得N，假设是 supported. 然而，确定何时N实际上可用于 植物是一项复杂的任务。 氮的有效性是 由土壤中的矿质氮含量决定， 这是一个N被添加（从雨或雪，或从分解 植物的相对能力， 土壤微生物获得这种N. 因此，年度模式 土壤中N离子浓度的变化， 这些离子从分解，和植物的相对能力， 和土壤微生物来吸收这些氮必须被确定。 这项研究意义重大，原因有几个。 一是 将促进对植物氮分配和植物- 高山环境中的营养关系。 的方式 植物如何分配其资源， 它从环境中获得的资源数量， 决定了植物的最终生存能力 二是 研究将探讨“在多大程度上”这一重要的一般性问题， 微生物与高等植物竞争氮吗？" 越来越多的人意识到，这种竞争可以产生强大的 影响植物营养状况。 这些问题具有实际意义。 比如说， 了解高山植物的氮储存， 深入了解果树越冬时会发生什么， 温带地区。 通过了解土壤温度如何影响N 在阿尔卑斯山骑自行车，科学家们可能能够提供洞察力， 在寒冷的农业系统中， 更有效地使用化肥和减少地下水的目标 氮肥污染。 最后， 硝酸盐转化为一氧化二氮（一种温室气体）受到许多因素的影响。 在这项研究中测试的土壤参数。 这些结果可能 有助于预测极地变暖对温室效应的影响 北极的气体排放。

This study tests the hypothesis that storing nitrogen over winter is an important adaptation in alpine plants. The alpine environment is characterized by: 1) a short growing season, (2) low soil temperatures, and 3) low nitrogen (N) availability. By using N that is stored during one growing season plants can begin growth in the following spring, even though soils are too cold for them to acquire N from the soil. This may allow them to take maximum advantage of the short alpine growth season and to quickly flower and set seed before the danger of frost becomes great. The investigators will determine when plants are using nitrogen for growth, and when plants are able to take nitrogen from the soil. If they find that plants start growing before they can acquire N in the spring, the hypothesis will be supported. However, determining when N is actually available to plants is a complicated task. Nitrogen availability is determined by the amount of mineral N in the soil, the rate at which this N is added (from rain or snow, or from decomposition of old plant matter) and the relative ability of plants versus soil microbes to acquire this N. Therefore, the annual pattern of N ion concentration in the soil, the rate of production of these ions from decomposition, and the relative ability of plants and soil microbes to assimilate this nitrogen must be determined. The study is significant for several reasons. First, it will advance basic understanding of plant N allocation and plant- nutrient relations in the alpine environment. The manner in which a plant allocates its resources can be as important as the quantity of resources it garners from the environment in determining a plant's ultimate ability to survive. Second, the study will address the important general question "to what extent do microorganisms compete for nitrogen with higher plants?" Awareness is growing that such competition can have a potent affect on plant nutrient status. These questions have practical implications. For example, an understanding of N storage in alpine plants may provide insight into what happens when fruit trees overwinter in temperate areas. By learning how soil temperature affects N cycling in the alpine, scientists may be able to provide insight into the fate of N fertilizer in cold agricultural systems with a goal of more efficient use of fertilizer and reduced ground water pollution by nitrogen fertilizers. Finally, denitrification of nitrate into nitrous oxide (a greenhouse gas) is affected by many of the soil parameters tested in this study. These results could be useful in predicting the effect of polar warming on greenhouse gas emissions from the arctic.