Application of Stable Isotope Mass Spectrometry in the Ecology of Nitrogen Cycle

In nature, radioactive isotope of nitrogen has a very short half-life, so ¹⁵N which is the only suitable natural tracer for ecological nitrogen cycle. Detecting the stable nitrogen isotope natural abundance or using the stable nitrogen isotope-labeled tracer, contributes to our understanding of nitrogen fixation, organic nitrogen mineralization, nitrification and denitrification processes in terrestrial ecosystems. In this paper, the nitrogen cycling processes in ecosystems and the related ¹⁵N isotopic fractionation during every processes were introduced. The theory and methods about the stable nitrogen isotope analysis and its application in the research of nitrogen cycling in recent years were reviewed. Finally, comprehensive summations of the problem existing in current research and in conjunction with the prospects of the future research on nitrogen cycling were proposed.