Fungal decomposition of terrestrial organic matter accelerated Early Jurassic climate warming
Nature Publishing Group
Soils – constituting the largest terrestrial carbon pool - are vulnerable to climatic warming. Currently existing uncertainties regarding carbon fluxes within terrestrial systems can be addressed by studies of past carbon cycle dynamics and related climate change recorded in sedimentary successions. Here we show an example from the Early Jurassic (early Toarcian, c. 183 mya) marginal-marine strata from Poland, tracking the hinterland response to climatic changes through a super-greenhouse event. In contrast to anoxia-related enhanced carbon storage in coeval open marine environments, Total Organic Carbon (TOC) concentrations in the Polish successions are substantially reduced during this event. Increasing temperature favoured fungal-mediated decomposition of plant litter – specifically of normally resistant woody tissues. The associated injection of oxidized organic matter into the atmosphere corresponds to abrupt changes in standing vegetation and may have contributed significantly to the amplified greenhouse climate on Earth. The characteristic Toarcian signature of multiple warm pulses coinciding with rapidly decreasing carbon isotope ratios may in part be the result of a radical reduction of the terrestrial carbon pool as a response to climate change.
This paper is a part of the project financed from resources of the Polish National Science Centre, granted on the basis of decision no. DEC-2012/06/M/ST10/00478. C.V.U. was supported by the Leopoldina - German National Academy of Sciences (grant no LPDS 2014-08), and G.P. by the scientific funds of the Polish Geological Institute, project 61.3608.1501.00.0. This is a contribution to the IGCP project 632 “Continental Crises of the Jurassic”. We thank Przemysław Karcz for performing RockEval pyrolithic analyses and Stephen Hesselbo and anonymous reviewer for valuable remarks.
This is the final version of the article. Available from Nature via the DOI in this record.
Scientific Reports, 2016, 6, Article no. 31930