1. Understanding the uncertainty in global forest carbon turnover
- Author
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T. A. M. Pugh, T. Rademacher, S. L. Shafer, J. Steinkamp, J. Barichivich, B. Beckage, V. Haverd, A. Harper, J. Heinke, K. Nishina, A. Rammig, H. Sato, A. Arneth, S. Hantson, T. Hickler, M. Kautz, B. Quesada, B. Smith, K. Thonicke, School of Geography, Earth and Environmental Sciences [Birmingham], University of Birmingham [Birmingham], Birmingham Institute of Forest Research (BIFoR), Department of Organismic and Evolutionary Biology [Cambridge] (OEB), Harvard University [Cambridge], School of Informatics, Computing, and Cyber Systems (SICCS), Northern Arizona University [Flagstaff], Center for Ecosystem Science and Society (ECOSS), Geosciences and Environmental Climate Change Science Center, United States Geological Survey [Reston] (USGS), Senckenberg Biodiversity and Climate Research Centre (SBiK-F), Goethe-Universität Frankfurt am Main-Senckenberg – Leibniz Institution for Biodiversity and Earth System Research - Senckenberg Gesellschaft für Naturforschung, Leibniz Association-Leibniz Association, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Universidad Austral de Chile, University of Vermont [Burlington], CSIRO Oceans and Atmosphere, CISRO Oceans and Atmosphere, College of Engineering, Mathematics and Physical Sciences [Exeter] (EMPS), University of Exeter, Potsdam Institute for Climate Impact Research (PIK), National Institute for Environmental Studies (NIES), Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), DEPARTMENT OF EARTH SYSTEM SCIENCES UNIVERSITY OF CALIFORNIA IRVINE CA USA, Partenaires IRSTEA, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Forest Research Institute Baden-Württemberg - Forstliche Versuchs- und Forschungsanstalt Baden-Württemberg, Universidad del Rosario [Bogota], DEPARTMENT OF PHYSICAL GEOGRAPHY AND ECOSYSTEM SCIENCE LUND UNIVERSITY SWE, Western Sydney University, Seventh Framework Programme, FP7: 50 603542 European Research Council, ERC: 758873 Centre National de la Recherche Scientifique, CNRS Svenska ForskningsrÃ¥det Formas: 211-2009-1682 Helmholtz Association Centre National de la Recherche Scientifique, CNRS, Financial support. This research has been supported by the Euro, pean Commission, European Research Council (TreeMort – grant no. 758873), Seventh Framework Programme (LUC4C – grant no. 50 603542), the Svenska Forskningsrådet Formas (Dnr. 211-2009-1682 and the strategic research areas BECC and MERGE), the Helmholtz Association ATMO programme, the Centre National de la Recherche Scientifique (CNRS) of France through the programme 'Make Our Planet Great Again', the U.S. Geological Survey Land Change Science Program, and the Helmholtz Alliance 'Remote Sensing and Earth System Dynamics'., Harvard University, and Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
- Subjects
0106 biological sciences ,010504 meteorology & atmospheric sciences ,Environmental change ,lcsh:Life ,01 natural sciences ,Carbon cycle ,lcsh:QH540-549.5 ,ddc:550 ,Baseline (configuration management) ,Ecology, Evolution, Behavior and Systematics ,0105 earth and related environmental sciences ,Earth-Surface Processes ,[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere ,Biomass (ecology) ,lcsh:QE1-996.5 ,Biosphere ,Soil carbon ,15. Life on land ,Plant functional type ,lcsh:Geology ,Earth sciences ,lcsh:QH501-531 ,[SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology ,13. Climate action ,Turnover ,lcsh:Ecology ,Physical geography ,010606 plant biology & botany - Abstract
The length of time that carbon remains in forest biomass is one of the largest uncertainties in the global carbon cycle, with both recent historical baselines and future responses to environmental change poorly constrained by available observations. In the absence of large-scale observations, models used for global assessments tend to fall back on simplified assumptions of the turnover rates of biomass and soil carbon pools. In this study, the biomass carbon turnover times calculated by an ensemble of contemporary terrestrial biosphere models (TBMs) are analysed to assess their current capability to accurately estimate biomass carbon turnover times in forests and how these times are anticipated to change in the future. Modelled baseline 1985–2014 global average forest biomass turnover times vary from 12.2 to 23.5 years between TBMs. TBM differences in phenological processes, which control allocation to, and turnover rate of, leaves and fine roots, are as important as tree mortality with regard to explaining the variation in total turnover among TBMs. The different governing mechanisms exhibited by each TBM result in a wide range of plausible turnover time projections for the end of the century. Based on these simulations, it is not possible to draw robust conclusions regarding likely future changes in turnover time, and thus biomass change, for different regions. Both spatial and temporal uncertainty in turnover time are strongly linked to model assumptions concerning plant functional type distributions and their controls. Thirteen model-based hypotheses of controls on turnover time are identified, along with recommendations for pragmatic steps to test them using existing and novel observations. Efforts to resolve uncertainty in turnover time, and thus its impacts on the future evolution of biomass carbon stocks across the world's forests, will need to address both mortality and establishment components of forest demography, as well as allocation of carbon to woody versus non-woody biomass growth.
- Published
- 2020