Global vegetation and terrestrial carbon cycle changes after the last ice age

• Published in: The New phytologist Vol. 189; no. 4; pp. 988 - 998
• Main Authors: Prentice, I. C., Harrison, S. P., Bartlein, P. J.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-03-2011; John Wiley & Sons; Wiley Subscription Services, Inc
• Subjects: Anomalies; Biomes; Boreal forests; Carbon capture and storage; Carbon Cycle; Carbon dioxide; Carbon sequestration; Climate change; Climate models; CO2; Computer Simulation; dynamic global vegetation model (DGVM); Ecophysiology; Ecosystem; forest; Forest biomass; Glaciation; Holocene; Ice; Ice ages; Industry; Intercomparison; Internationality; Isotopes; last glacial maximum (LGM); Models, Biological; Palaeoclimate; Paleoclimatology; Plants; Plants - metabolism; Pollen; Primary production; Productivity; Sclerophyll forests; sink; Stable isotopes; Terrestrial environments; Thickening; Time Factors; Tropical climate; Tropical forests; Uptake; Vegetation; woody thickening
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/j.1469-8137.2010.03620.x

• In current models, the ecophysiological effects of CO₂ create both woody thickening and terrestrial carbon uptake, as observed now, and forest cover and terrestrial carbon storage increases that took place after the last glacial maximum (LGM). Here, we aimed to assess the realism of modelled vegetation and carbon storage changes between LGM and the pre-industrial Holocene (PIH). • We applied Land Processes and eXchanges (LPX), a dynamic global vegetation model (DGVM), with lowered CO₂ and LGM climate anomalies from the Palaeoclimate Modelling Intercomparison Project (PMIP II), and compared the model results with palaeodata. • Modelled global gross primary production was reduced by 27-36% and carbon storage by 550-694 Pg C compared with PIH. Comparable reductions have been estimated from stable isotopes. The modelled areal reduction of forests is broadly consistent with pollen records. Despite reduced productivity and biomass, tropical forests accounted for a greater proportion of modelled land carbon storage at LGM (28-32%) than at PIH (25%). • The agreement between palaeodata and model results for LGM is consistent with the hypothesis that the ecophysiological effects of CO₂ influence tree-grass competition and vegetation productivity, and suggests that these effects are also at work today.