A globally relevant stock of soil nitrogen in the Yedoma permafrost domain

Nitrogen regulates multiple aspects of the permafrost climate feedback, including plant growth, organic matter decomposition, and the production of the potent greenhouse gas nitrous oxide. Despite its importance, current estimates of permafrost nitrogen are highly uncertain. Here, we compiled a dataset of >2000 samples to quantify nitrogen stocks in the Yedoma domain, a region with organic-rich permafrost that contains similar to 25% of all permafrost carbon. We estimate that the Yedoma domain contains 41.2 gigatons of nitrogen down to similar to 20metre for the deepest unit, which increases the previous estimate for the entire permafrost zone by similar to 46%. Approximately 90% of this nitrogen (37 gigatons) is stored in permafrost and therefore currently immobile and frozen. Here, we show that of this amount, 3/4 is stored >3 metre depth, but if partially mobilised by thaw, this large nitrogen pool could have continental-scale consequences for soil and aquatic biogeochemistry and global-scale consequences for the permafrost feedback.

Automated summary

Nitrogen plays a crucial role in regulating various aspects of the permafrost climate feedback, but its estimates are highly uncertain. This study provides new estimates of nitrogen stocks in the Yedoma domain, showing an increase of 46% compared to previous estimates for the entire permafrost zone. The large nitrogen pool stored in permafrost could have significant regional and global consequences if partially mobilized by thawing.