Gopal Bhatt
Gary W. Shenk
Lewis C. Linker
Isabella Bertani
2022
<div class="abstract-group"><div class="article-section__content en main"><p><span>Excessive nitrogen (N) inputs to coastal waters can lead to severe eutrophication and different chemical forms of N exhibit varying levels of effectiveness in fueling primary production. Efforts to mitigate N fluxes from coastal watersheds are often guided by models that predict changes in N loads as a function of changes in land use, management practices, and climate. However, relatively little is known on the impacts of such changes on the relative fractions of different N forms. We leveraged a long-term dataset of N loads from over 100 river stations to investigate how the </span><img class="section_image" src="https://onlinelibrary.wiley.com/cms/asset/a3d9d6cf-c64f-4441-b62f-40caf3f469d4/jawr12951-math-0001.png" alt="urn:x-wiley:1093474X:media:jawr12951:jawr12951-math-0001" data-mce-src="https://onlinelibrary.wiley.com/cms/asset/a3d9d6cf-c64f-4441-b62f-40caf3f469d4/jawr12951-math-0001.png"><span> fraction, that is, the ratio of </span><img class="section_image" src="https://onlinelibrary.wiley.com/cms/asset/4a4f01f2-11c1-425a-91e5-bd866e82536c/jawr12951-math-0002.png" alt="urn:x-wiley:1093474X:media:jawr12951:jawr12951-math-0002" data-mce-src="https://onlinelibrary.wiley.com/cms/asset/4a4f01f2-11c1-425a-91e5-bd866e82536c/jawr12951-math-0002.png"><span> to total N (</span><img class="section_image" src="https://onlinelibrary.wiley.com/cms/asset/b3f3cd5d-5897-4631-987e-94311a21e62d/jawr12951-math-0003.png" alt="urn:x-wiley:1093474X:media:jawr12951:jawr12951-math-0003" data-mce-src="https://onlinelibrary.wiley.com/cms/asset/b3f3cd5d-5897-4631-987e-94311a21e62d/jawr12951-math-0003.png"><span>/TN), changes as a function of spatio-temporal changes in TN loads in the Chesapeake Bay watershed. We built a hierarchical model that separates the response of </span><img class="section_image" src="https://onlinelibrary.wiley.com/cms/asset/7acf019a-c0c3-44ea-88c7-1554299a59e4/jawr12951-math-0004.png" alt="urn:x-wiley:1093474X:media:jawr12951:jawr12951-math-0004" data-mce-src="https://onlinelibrary.wiley.com/cms/asset/7acf019a-c0c3-44ea-88c7-1554299a59e4/jawr12951-math-0004.png"><span> to changes in TN load occurring at different scales: </span><i>Across</i><span> river stations, where differences in TN loads are largely driven by spatial differences in anthropogenic inputs, and </span><i>within</i><span> stations, where inter-annual variability in hydrology is a key driver of changes in TN loads. Results suggest that while increases in TN loads resulting from changes in anthropogenic inputs lead to an increase in the </span><img class="section_image" src="https://onlinelibrary.wiley.com/cms/asset/98b998f4-da5a-4ea9-9d5c-805351d51cc8/jawr12951-math-0005.png" alt="urn:x-wiley:1093474X:media:jawr12951:jawr12951-math-0005" data-mce-src="https://onlinelibrary.wiley.com/cms/asset/98b998f4-da5a-4ea9-9d5c-805351d51cc8/jawr12951-math-0005.png"><span> fraction, a decrease in the </span><img class="section_image" src="https://onlinelibrary.wiley.com/cms/asset/6125f6b3-ed31-4b86-a896-4a020811de27/jawr12951-math-0006.png" alt="urn:x-wiley:1093474X:media:jawr12951:jawr12951-math-0006" data-mce-src="https://onlinelibrary.wiley.com/cms/asset/6125f6b3-ed31-4b86-a896-4a020811de27/jawr12951-math-0006.png"><span> fraction may occur when increases in TN loads are driven by increased streamflow. These results are especially relevant in watersheds that may experience changes in N loads due to both management decisions and climate-driven changes in hydrology.</span></p></div></div>
application/pdf
10.1111/1752-1688.12951
en
Wiley
Quantifying the response of nitrogen speciation to hydrology in the Chesapeake Bay Watershed using a multilevel modeling approach
article