Decades of research in terrestrial ecosystems and the open ocean have quantified rates and revealed environmental controls of biological nitrogen fixation (N₂ fixation), the microbial conversion of dinitrogen gas to biologically reactive ammonium. However, N₂ fixation rates, and the diversity of the organisms that fix N₂ remain largely unconstrained in the aquatic landscapes or aquascapes (e.g., lakes, wetlands, streams, rivers, estuaries) between land and sea. As a result, we lack a mechanistic understanding of the controls and contributions of N₂ fixation across disparate aquatic environments, and cannot accurately incorporate this process into local and global N budgets. To advance understanding of N₂ fixation in aquascapes, we will bring together scientists studying this process in any environment, from land to sea. In this union/special session we will highlight the latest N₂ fixation research describing rates and environmental controls as well as the biological diversity of N₂ fixing communities. We encourage participants using any methods or approaches – from micro- to macroscales. Our session will include in-person and virtual invited talks and discussion.

Potential Speakers

Jason Taylor, USDA Agricultural Research Service – Nitrogen fixation in agricultural streams

Mar Benavides, Mediterranean Institute of Oceanography – Autotrophic nitrogen fixation in the ocean

Angela Knapp, Florida State University – Heterotrophic nitrogen fixation in the ocean

Duncan Menge, Columbia University – Nitrogen fixation in forests

Potential Schedule

A series of talks, followed by a panel discussion. We would like to include posters as well. And we envision having both in-person and virtual presentations.

• CGU: Canadian Geophysical Union -
• ESA: Ecological Society of America -
• EGU: European Geosciences Union -
• SSSA: Soil Science Society of America -