We use a portable X-ray fluorescence (PXRF) instrument to provide authentic research activities in lower and upper division courses in ecology, archeology, chemistry, and earth sciences. In doing so we are exploring methods to merge (not separate) “teaching” from “research”; and to develop models that feed into existing undergraduate courses. Combining PXRF techniques with inquiry-based laboratory activities encourages students to solve real-world problems and engages them in multidisciplinary research. Students in General Ecology built on a 4-week lab based on the classic decomposition study (Melillo et al. 1982) presented as a case study in Molles textbook (4e 2008). That lab was expanded by asking the students to measure leaf tissue K and Ca, from pre- and post-decomposition tissues (collected on-campus) from the same five tree species used in the case study. Because Ca and K measurements were not published in the original study, students began by searching the primary literature for leaf tissue Ca and K changes associated with decomposition with the five tree species. Using those findings, they made predictions about the amount and direction of change. Using the PXRF they compared their findings with their predictions as well the patterns and trends that were identified from the literature. Results/Conclusions