Dinosaur diets and methane emissions

The ambient concentration of carbon dioxide in the growth environment of plants controls the relative abundance of macronutrients (carbohydrate, protein and lipids) in their tissues. This may affect the metabolizable energy (ME) value of the plant, i.e. how much energy an animal can obtain from the plant by eating it.

Previous work (Hummel et al., 2008) has determined the ME values of several putative sauropod dinosaur food plants but did not consider the possible effect of elevated CO2 levels during the Mesozoic. This research will address this issue by growing plants under present day and Mesozoic CO2 levels and determining the ME value of each. Plant growth experiments will be carried out in collaboration with Barry Lomax, University of Nottingham and fermentation experiments to determine ME will be carried out in collaboration with Dr Jurgen Hummel, University of Bonn. The energy loss due to methanogenesis during fermentation of the plant material will be quantified and concentrations of methane and the methanogen lipid biomarker archaeol (Gill et al., 2011) will also be measured.

This project will determine for the first time how elevated levels of carbon dioxide may have affected the nutritional value of dinosaur food plants. It may also lead to the development of a new method of estimating methane emissions from herbivores if a consistent relationship is found between the concentrations of methane and archaeol in the experimental system. This research will also provide insights into the effects of elevated CO2 levels on plant macronutrient balance, which could contribute to better understanding of the response of human food crops to current atmospheric CO2 increase.

Further reading:

Gill, FL; Dewhurst, RJ; Evershed, RP; McGeough, E; O'Kiely, P; Pancost, RD; Bull, ID (2011) Analysis of archaeal ether lipids in bovine faeces. Animal Feed Science and Technology, 166-67, pp.87-92.

Hummel, J; Gee, C T; Südekum, K H; Sander, P M; Nogge, G; Clauss, M (2008). In vitro digestibility of fern and gymnosperm foliage: implications for sauropod feeding ecology and diet selection. Proceedings of The Royal Society B Biological Sciences, 275(1638):1015-1021.