Home > Articles > Published articles > Regime shifts of Mediterranean forest carbon uptake and reduced resilience driven by multidecadal ocean surface temperatures |
Date: | 2019 |
Abstract: | The mechanisms translating global circulation changes into rapid abrupt shifts in forest carbon capture in semi-arid biomes remain poorly understood. Here, we report unprecedented multidecadal shifts in forest carbon uptake in semi-arid Mediterranean pine forests in Spain over 1950-2012. The averaged carbon sink reduction varies between 31% and 37%, and reaches values in the range of 50% in the most affected forest stands. Regime shifts in forest carbon uptake are associated with climatic early warning signals, decreased forest regional synchrony and reduced long-term carbon sink resilience. We identify the mechanisms linked to ocean multidecadal variability that shape regime shifts in carbon capture. First, we show that low-frequency variations of the surface temperature of the Atlantic Ocean induce shifts in the non-stationary effects of El Niño Southern Oscillation (ENSO) on regional forest carbon capture. Modelling evidence supports that the non-stationary effects of ENSO can be propagated from tropical areas to semi-arid Mediterranean biomes through atmospheric wave trains. Second, decadal changes in the Atlantic Multidecadal Oscillation (AMO) significantly alter sea-air heat exchanges, modifying in turn ocean vapour transport over land and land surface temperatures, and promoting sustained drought conditions in spring and summer that reduce forest carbon uptake. Third, we show that lagged effects of AMO on the winter North Atlantic Oscillation also contribute to the maintenance of long-term droughts. Finally, we show that the reported strong, negative effects of ocean surface temperature (AMO) on forest carbon uptake in the last decades are unprecedented over the last 150 years. Our results provide new, unreported explanations for carbon uptake shifts in these drought-prone forests and review the expected impacts of global warming on the profiled mechanisms. |
Grants: | European Commission 641762 European Commission 610028 Ministerio de Economía y Competitividad CGL2016-78093-R Ministerio de Economía y Competitividad CGL2015-69888-P Ministerio de Economía y Competitividad CGL2013-48277-P Ministerio de Economía y Competitividad CGL2013-48074-P Ministerio de Economía y Competitividad CGL2012-33927 Ministerio de Economía y Competitividad CGL2011-26654 Ministerio de Economía y Competitividad CGL2010-17172 Ministerio de Economía y Competitividad CSD2008-00040 Agència de Gestió d'Ajuts Universitaris i de Recerca 2017/SGR-1690 Agència de Gestió d'Ajuts Universitaris i de Recerca 2017/SGR-1005 Agència de Gestió d'Ajuts Universitaris i de Recerca 2009/SGR-458 Agència de Gestió d'Ajuts Universitaris i de Recerca FI-2013 |
Note: | imbalance-p paper contact with j.carnicer@creaf.uab.cat |
Rights: | Tots els drets reservats. |
Language: | Anglès |
Document: | Article ; recerca ; Versió acceptada per publicar |
Subject: | Carbon sink ; Climate ; Forest ; Multidecadal drought ; Regime shift ; Resilience |
Published in: | Global change biology, Vol. 25, issue 8 (August 2019) , p. 2825-2840, ISSN 1365-2486 |
Postprint 50 p, 1.9 MB |