| Stable nitrogen isotopes have long been used in food web and ecological studies. This study attempted to relate the stable nitrogen isotope ratio found in periphyton and aquatic macro invertebrates (Baetids spp.) to different levels and intensities of land use in watersheds across Utah. The project also included a smaller pilot study that examined the effects of a feedlot on stable nitrogen isotopes. Overall, the watershed scale study showed that stable nitrogen isotopes are best suited for identifying local anthropogenic sources of nitrogen and are poorly related to land use at larger scales. The pilot study identified several potential complications in the use of stable isotopes at site-specific projects. In particular, hydrology, potential nutrient limitation, and presence of appropriate target species are critical to the success of these studies. |
