Decadal increases in carbon uptake offset by respiratory losses across northern permafrost ecosystems
Craig R. See, Anna‐Maria Virkkala, Susan M. Natali, Brendan M. Rogers, Marguerite Mauritz, Christina Biasi, Stef Bokhorst, Julia Boike, M. Syndonia Bret‐Harte, Gerardo Celis, Namyi Chae, Torben R. Christensen, Sara June Murner, Sigrid Dengel, A. J. Dolman, Colin W. Edgar, Bo Elberling, Craig A. Emmerton, E. S. Euskirchen, Mathias Göckede, Achim Grelle, Liam Heffernan, Manuel Helbig, David Holl, Elyn Humphreys, Hiroki Iwata, Järvi Järveoja, Hideki Kobayashi, John Kochendorfer, Pasi Kolari, Ayumi Kotani, Lars Kutzbach, Min Jung Kwon, Emma Lathrop, Efrèn López‐Blanco, Ivan Mammarella, Maija E. Marushchak, Mikhail Mastepanov, Yojiro Matsuura, Lutz Merbold, Gesa Meyer, Christina Minions, Mats B. Nilsson, Julia Nojeim, Steven F. Oberbauer, David Olefeldt, Sang‐Jong Park, Frans‐Jan W. Parmentier, Matthias Peichl, D. L. Peter, Roman Petrov, Rafael Poyatos, Anatoly Prokushkin, William L. Quinton, Heidi Rodenhizer, Torsten Sachs, K. E. Savage, Christopher Schulze, Sofie Sjögersten, Oliver Sonnentag, Vincent L. St. Louis, Margaret Torn, Eeva‐Stiina Tuittila, Masahito Ueyama, Andrej Varlagin, Carolina Voigt, Jennifer D. Watts, Donatella Zona, Viacheslav I. Zyryanov, Edward A. G. Schuur
Abstract
Abstract Tundra and boreal ecosystems encompass the northern circumpolar permafrost region and are experiencing rapid environmental change with important implications for the global carbon (C) budget. We analysed multi-decadal time series containing 302 annual estimates of carbon dioxide (CO 2 ) flux across 70 permafrost and non-permafrost ecosystems, and 672 estimates of summer CO 2 flux across 181 ecosystems. We find an increase in the annual CO 2 sink across non-permafrost ecosystems but not permafrost ecosystems, despite similar increases in summer uptake. Thus, recent non-growing-season CO 2 losses have substantially impacted the CO 2 balance of permafrost ecosystems. Furthermore, analysis of interannual variability reveals warmer summers amplify the C cycle (increase productivity and respiration) at putatively nitrogen-limited sites and at sites less reliant on summer precipitation for water use. Our findings suggest that water and nutrient availability will be important predictors of the C-cycle response of these ecosystems to future warming.