Nitrogen fixation across the aquascape: current perspectives, future priorities

Abstract

Di-nitrogen (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 nitrogen (N) budgets. This special issue brings together papers highlighting current advances in understanding of N2 fixation within and across all aquatic habitats, integrating novel methodology for studying N2 fixation, quantification of N2 fixation fluxes in understudied habitats, the role of N2 fixation in biotic assemblages, and the rate and fate of fixed N in heterogeneous landscapes. Together, these papers address important gaps in understanding and highlight the frontiers of research on N2 fixation in aquatic habitats.