William J. Riley Sara H. Knox Robert B. Jackson Gavin McNicol Benjamin Poulter Mika Aurela Dennis Baldocchi Sheel Bansal Gil Bohrer David I. Campbell Alessandro Cescatti Housen Chu Kyle B. Delwiche Ankur R. Desai Eugenie S. Euskirchen Matthias Goeckede Thomas Friborg Kyle S. Hemes Takashi Hirano Hiroki Iwata Manuel Helbig Trevor F. Keenan Minseok Kang Ken Krauss Annalea Lohila Bhaskar Mitra Ivan Mammarella Akira Miyata Mats B. Nilsson Walter C. Oechel Akso Noormets Matthias Peichl Michele L. Reba Janne Rinne Dario Papale Benjamin R. K. Runkle Youngryel Ryu Torsten Sachs Karina VR Schafer Hans Peter Schmid Narasinha Shurpali Oliver Sonnentag Angela Tang Margaret S. Torn Eeva-Stiina Tuittila Carlo Trotta Masahito Ueyama Rodrigo Vargas Timo Vesala Lisamarie Windham-Myers Zhen Zhang Donatella Zona Kuang-Yu Chang 2021 <p><span>Wetland methane (CH</span>₄<span>) emissions (</span><span class="mathjax-tex"><span id="MathJax-Element-1-Frame" class="MathJax" data-mathml="<math xmlns=">FCH₄</span></span><span>) are important in global carbon budgets and climate change assessments. Currently,&nbsp;</span><span class="mathjax-tex"><span id="MathJax-Element-2-Frame" class="MathJax" data-mathml="<math xmlns=">FCH₄</span></span><span> projections rely on prescribed static temperature sensitivity that varies among biogeochemical models. Meta-analyses have proposed a consistent <span class="mathjax-tex"><span id="MathJax-Element-2-Frame" class="MathJax" data-mathml="<math xmlns=">FCH₄</span></span></span><span> temperature dependence across spatial scales for use in models; however, site-level studies demonstrate that <span class="mathjax-tex"><span id="MathJax-Element-2-Frame" class="MathJax" data-mathml="<math xmlns=">FCH₄</span></span></span><span> are often controlled by factors beyond temperature. Here, we evaluate the relationship between <span class="mathjax-tex"><span id="MathJax-Element-2-Frame" class="MathJax" data-mathml="<math xmlns=">FCH₄</span></span></span><span>&nbsp;and temperature using observations from the FLUXNET-CH</span>₄<span> database. Measurements collected across the globe show substantial seasonal hysteresis between <span class="mathjax-tex"><span id="MathJax-Element-2-Frame" class="MathJax" data-mathml="<math xmlns=">FCH₄</span></span></span><span> and temperature, suggesting larger <span class="mathjax-tex"><span id="MathJax-Element-2-Frame" class="MathJax" data-mathml="<math xmlns=">FCH₄</span></span></span><span>&nbsp;sensitivity to temperature later in the frost-free season (about 77% of site-years). Results derived from a machine-learning model and several regression models highlight the importance of representing the large spatial and temporal variability within site-years and ecosystem types. Mechanistic advancements in biogeochemical model parameterization and detailed measurements in factors modulating CH</span>₄<span>&nbsp;production are thus needed to improve global CH</span>₄<span>&nbsp;budget assessments.</span></p> application/pdf 10.1038/s41467-021-22452-1 en Springer Substantial hysteresis in emergent temperature sensitivity of global wetland CH4 emissions article