Changes in coupled carbon‒nitrogen dynamics in a tundra ecosystem predate post-1950 regional warming

• Published in: Communications Earth & Environment
• Main Authors: Anderson, N. John, Engstrom, Daniel R., Leavitt, Peter R., Flood, Sarah M., Heathcote, Adam J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature Research 2020
• Subjects: Arctic; north slope; Tundra; Alaska
• Online Access: http://hdl.handle.net/10294/15885; https://doi.org/10.1038/s43247-020-00036-z

© 2020 The Authors. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/ licenses/by/4.0/. Arctic ecosystems are changing in response to recent rapid warming, but the synergistic effects of other environmental drivers, such as moisture and atmospheric nitrogen (N) deposition, are difficult to discern due to limited monitoring records. Here we use geo- chemical analyses of 210 Pb-dated lake-sediment cores from the North Slope of Alaska to show that changes in landscape nutrient dynamics started over 130 years ago. Lake carbon burial doubled between 1880 and the late-1990s, while current rates (~10 g C m−2 yr−1) represent about half the CO2 emission rate for tundra lakes. Lake C burial reflects increased aquatic production, stimulated initially by nutrients from terrestrial ecosystems due to late- 19 th century moisture-driven changes in soil microbial processes and, more recently, by atmospheric reactive N deposition. These results highlight the integrated response of Arctic carbon cycling to global environmental stressors and the degree to which C–N linkages were altered prior to post-1950 regional warming. Faculty yes