Experimental Design and Interpretation of Terrestrial Ecosystem Studies Using 15N Tracers: Practical and Statistical Considerations

The stable isotope 15 N is an extremely useful tool for studying the nitrogen (N) cycle of terrestrial ecosystems. affordability isotope-ratio mass spectrometry has increased in last decades and routine measurements ? with accuracy better than 1‰ are now easily achieved. Except perhaps wood, which a very high C/N ratio, analysis samples is, thus, no longer main challenge measuring partitioning used as tracer ecosystem studies. central aim such experiments to quantitatively determine fate after it enters ecosystem, mainly fertilizer, atmospheric deposition or plant litter. By how much this incoming goes into different pools, inferences can be made about entire cycle. Sample collection preparation tedious work. Optimizing sampling schemes thus important aspect application research helpful obtaining precision results available manpower budget. In contribution, we combine statistical practical considerations give recommendations design labeling also assessments natural abundance. particular, discuss soil, vegetation water sampling. We additionally address most common questions arising during calculation partitioning, provide some examples interpretation experimental results.