Modern plant δ15N values reflect ancient human activity

We have observed circumstances in which the ancient human activities that formed archaeological sites have left a strong imprint on the stable nitrogen isotopic ratio of the plants currently growing there. There is apparent meter-scale spatial variability and the effect can persist for at least several centuries. To our knowledge, this isotopic effect has not previously been reported. Here, we introduce this phenomenon and begin to consider its potential as an analytical tool in archaeological reconstruction.