Supervisors and Institutions
The increases in atmospheric concentrations of CO2 (pCO2), that are associated with climate change, cause decreases in the nutritional value of plants to the herbivorous insects that feed upon them. In turn, these changes in plant quality are a key determinant in the reproduction and survival of herbivorous insects at both the individual and the population scale. By investigating past periods of global warming with high atmospheric pCO2 over long timescales we can increase our understanding of the nature and scale of potential future changes in insect-plant interactions.
The geological record contains a number of well-documented fossilized insect beds, but the reasons for their distribution through geological time have not yet been examined. Although a relationship between fossil insect accumulations, changes in plants, and changes in atmospheric composition have been suggested they have never been demonstrated.
This project will firstly make a general assessment of insect fossil distribution through both space and time in the Mesozoic. The project will then focus on the thousands of insects found throughout the UK and Europe in association with the extreme environmental change event that occurred during the Toarcian (183 Ma, Early Jurassic) by documenting the changes in the insect and plant communities at this time. During the Toarcian event, global temperatures rose by approximately 7-10°C, large quantities of CO2 were released into the ocean-atmosphere system and there was an increased hydrological cycle. The scale of the changes during the Toarcian event are comparable with the IPCC climate predictions for 2099 under the high emissions scenarios. A geochemical and macrofossil study of the Toarcian in Leicestershire which shows the event had a major impact on marine biota also suggests there might be a link between the preservation of insect beds and key stages in the climatic change. Additionally, it has been suggested that Coelorrhyncha evolved during the Toarcian and their modern counterparts would indicate that this may be related to increased humidity and decomposition rates.