Nitrogen isotope fractionation and nitrogen plant nutrition study in alpine ecosystems of the Northern Caucasus

拟议的研究将评估利用高山植物物种的稳定氮同位素组成(N-15自然丰度)和不稳定的土壤氮库(铵、硝酸盐、溶解有机氮)来确定北高加索高山群落中个别植物物种(或不同群体)的N营养来源的前景。这项研究涉及特伯尔达国家级保护区(俄罗斯联邦卡拉恰沃-切尔克西亚共和国)四个不同高山生态系统的20种物种，实验包括实验室和田间(包括时间动态)操作，不同来源的N有效性(KNO3和NH4CI)来自不同来源(15N为9.5%o，NH4CI为-8，5%o的15N)，并观察植物和土壤N库中15N的变化。

The proposed research will estimate the prospects to use the composition of stable nitrogen isotopes (N-15 natural abundance) of alpine plant species and labile soil N pools (ammonium, nitrate, dissolved organic nitrogen) to identify sources of N-nutrition for individual plant species (or separate groups) in alpine communities of the Northern Caucasus. The study involves 20 species from four different alpine ecosystems in the Teberda National Reserve (Karachaevo- Cherkessiya Republic, Russian Federation), Experimentation includes laboratory and field (including temporal dynamics) manipulations with N availability from different sources (KNO3 with (15N of 9.5%o, and NH4CI with (15N of -8,5%o) and observations for (15N changes in plant and soil N pools.