Trees rings record a wealth of information on climate, disturbance, and forest dynamics, and can record these processes from the plot to regional to global scales. However, extracting plant physiological processes from the tree ring record has proved to be more difficult, as integration of leaf to whole tree processes can often lead to confounding results. My research aims to bring a plant ecophysiological perspective to interpreting the tree ring record and to ask, what processes are the rings actually recording? Can different species growing in the same location record different environmental parameters? I will use examples from two contrasting environments: the Northern Rocky Mountains and the Galapagos Islands.