Forested Watershed Responses to Chronic Nitrogen Additions
The Elliott lab leverages advanced stable isotope geochemistry to unravel the complexities of nitrogen cycling in forested watersheds, particularly under chronic atmospheric nitrogen deposition. By integrating mass-independent nitrate isotopes (Δ17O-NO3−) alongside traditional dual isotopes (δ15N and δ18O), the lab distinguishes between atmospheric and microbial nitrogen contributions, providing unprecedented resolution in tracing nitrogen transformations. High-resolution storm event monitoring at Fernow Experimental Forest, WV, revealed extreme isotopic variability within precipitation nitrate, underscoring the need for event-scale nitrogen assessments over traditional low-frequency sampling.
Findings demonstrate that microbial nitrification, rather than direct atmospheric deposition, dominates streamwater nitrate production even at the highest deposition rates observed, challenging long-standing nitrogen saturation models and emphasizing the resilience of microbial processing. This transformative research not only refines nitrogen budgets but also highlights the urgent need for adaptive watershed nitrogen management strategies and climate-resilient monitoring programs. These efforts ensure more effective policies and contribute to sustainable ecosystem management, offering exciting opportunities for graduate students and collaborators to tackle critical environmental challenges.
Representative Publications
Rose, L.A., Elliott, E.M., Bain, D.J., Pardo, L.H. (2015a). Evaluating the influence of atmospheric nitrate deposition on nitrate export from forested watersheds using Δ17O. Geophysical Research Letters, 42(9), 3482-3489. https://doi.org/10.1002/2015GL063699
Rose, L.A., Pardo, L.H., Elliott, E.M. (2015b). Nitrate sources and transformations in forested watersheds: Insights from triple oxygen isotopes. Journal of Geophysical Research: Biogeosciences, 120(9), 1824-1840. https://doi.org/10.1002/2015JG003128
Rose, L.A., Yu, Z., Bain, D.J., Elliott, E.M. (2019). High resolution, extreme isotopic variability of precipitation nitrate. Atmospheric Environment, 207, 63-74. https://doi.org/10.1016/j.atmosenv.2019.03.012