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Choose a Project: Projects Home Page 1. Atmospheric CO2 & Leaf Evolution 2. Polar Forests - Carbon Balance 3. Polar Forests - Distribution and Ecology 4. Biogenic Trace Gas Fluxes 5. The Evolution of C4 Plants 6. Palaeoceanographic changes 7. Biodiversity Response to Climate Change 8. Evolution of C4 Photosynthesis 9. Terminal Cretaceous Climate Change 10. C4 phylogenetic history

Personnel
Principal investigator:
Marie Cure Research Fellow:
Related research personnel:

Professor D.J. Beerling
Dr L. Lorens
Dr. C. Osborne
Dr D.L. Royer (Penn. State University, USA)

Project dates
October 1999 to September 2001 (NERC), October 2001 - December 2002 RS/NSF), January 2003-December 2005 (EU)

Summary
For most of the past 500 million years the Earth has experienced a warmer climate than today, with the polar regions being largely ice-free. We now know from palaeobotanical investigations that in place of the huge continental ice sheets so familiar today were forests of tall coniferous trees. This important discovery, around 100 years ago, ranks as one of the most exciting in the field of palaeobotany. Despite the century that has elapsed since then we still know rather little about how these forests adapted to the polar light environment, with its long periods of winter darkness followed by several weeks of continuous daylight. In particular the role of leaf habit (deciduous versus evergreen) remains a hotly debated topic. Did these forests, for example, have to shed leaves during the polar winter, to reduced their carbon losses by canopy respiration, to survive ?
We are addressing these issues for the first time by taking an experimental approach. In 1999, we established a fully replicated polar greenhouse facility for simulating high-latitude light regimes and climates. The facility has full atmospheric CO₂ control allowing us to mimic the CO₂ concentration under which these forests grew millions of years ago. This research aims to determine the effects of leaf habit and growth atmospheric CO₂ level on the carbon balance of a range of deciduous and evergreen taxa (dawn redwood, coastal redwood, swamp cypress, southern beech and maidenhair tree). These species were deliberately selected because they have a long fossil record, species Charles Darwin called 'living fossils'. The underpinning philosophy of the experiment is that we can better interpret the past fossil history of these species by performing experiments on the remnant genotypes that survive today.

Check out our latest research findings by clicking on the logo to download the paper below:

Beerling, D.J. & Osborne, C.P. (2002) Physiological ecology of Mesozoic polar forests in a high CO₂ environment. Annals of Botany, 89, 329-339. 201KB

Royer, D.L., Osborne, C.P. & Beerling, D.J. (2002) High CO₂ increases the freezing sensitivity of plants: implications for paleoclimatic reconstructions from fossil floras. Geology, 30 (11), 963-966. 310KB

Outside view of the growth rooms.

Inside view of the growth rooms. Note the water-cooled lamps that prevent the saplings from being scorched.

Replicate chambers designed for measuring the carbon balance of high-latitude palaeo-forest trees.

To be deciduous or not ? That is the palaeoecological question.