Using Stable Isotopes as Indicators, Tracers, and Recorders of Ecological Change: Some Context and Background

The stable isotope investigations have grown steadily in the past 50 years or so and have become a cornerstone for many ecological investigations since the 1980s. The understanding of the many processes that lead to isotopic variation in natural environments is now often well understood and is improving each year. The challenge that is now being confronted with, is to extend what is known about these processes and the products that result from them, to see how changes have been ‘‘recorded’’ and how these changes can be interpreted. This requires a different approach that many past ecological investigations have not taken and one that forces ecologists to find materials such as carbonates, feathers, hard tissues, hair, tree-ring cellulose, and the many chemical compounds that compose them, so that they can be used to trace and therefore record change. By linking known processes to these changes, the growing field of ‘‘ecological forensics'’ that has emerged, is now documenting changes in many novel and powerful ways.Through innovative stable isotope methods and their novel application, the manner and magnitude of ecological transformations are now being documented across a wide range of natural systems. The environmental and ecological changes will continue and in many instances, will accelerate. Applying stable isotope analyses in these ways can lead to solutions that will help mitigate future ecosystem damage and environmental degradation.