ABSTRACT

Ammonium fractions from a soil of a penguin rookery in Antarctica and from water of a pond in the rookery exhibit the highest ¹⁵N/¹⁴N ratios among biogenic nitrogen so far observed. Though soils of seabird rookeries appear, in general, to have high nitrogen isotope ratios, the still higher ratios make the penguin rookery stand out from other seabird rookeries. The observation suggests that ammonia volatilization is a cause of the ¹⁵N enrichment in the soil ammonium and that the Antarctic climate is particularly effective on ¹⁵N enrichment for ammonium remained in the soil and water.