Phillips, D.L. 2001. Mixing models in analyses of diet using multiple stable isotopes: a critique. Oecologia 127:166-170
Stable isotopes have become widely used in ecology to quantify the importance of different sources based on their isotopic signature. One example of this has been the determination of food webs, where the isotopic signatures of a predator and various prey items can be used to determine the proportion of each prey item consumed. A Corvallis scientist has examined several of the equations commonly used for this purpose, determined that they give erroneous results under many circumstances, and provided alternative equations which resolve these problems. This method is capable of accurately partitioning sources for other environmental processes as well, potentially including tracing sources of pollutants.