Environmental Change
Research Team
Dr Barry Lomax
Mr Jim Craigon
Professor Neil Crout
Dr Sofie Sjogersten
Research Overview
Environmental change is one of the most pressing problems facing humanity at present. Research into this diverse theme within the division is equally diverse and spans a variety of topics, different geographical locations, and seeks to reconstruct changes in key environmental parameters through geological time.
Current projects
Monitoring and modelling methane production by dairy cows
This collaboration with the Animal Science division is funded by DEFRA to monitor the individual methane eructations of over 200 cows while being milked by the University of Nottingham’s robotic milking machines which the cows choose to use 2 to 4 times a day. Not all cows produce the same amount of this important greenhouse gas; an unwanted by-product of rumin fermentation. Closed chamber-based studies are being used to relate the milking-time methane measurements to the total methane production by the cow. Analysis and modelling of the extensive data set produced will enable the scale and nature of within and between cow variation in methane production to be determined and the opportunity for breeding or feeding strategies to reduce the methane output while maintaining food production to be assessed. Earlier climate change work includes open top chamber studies on the effects of elevated ozone and CO2 on field grown crops.
Inland Antarctic lakes
We were involved with the multi-disciplinary Equator project (funded by the EPSRC), studying the dyna
mics of Antarctic lakes. The project included researchers from the School of Electrical and Electronic Engineering and the School of Computer Science and Information Technology. Fieldwork was supported by the Australian Antarctic Division. Inland Antarctic lakes are among the harshest environments in the world for life to inhabit, and are widely regarded as sensitive indicators of climate change. In 2003 an automatic probe was deployed on Crooked Lake, a freshwater lake in Eastern Antarctica. The probe measures several meteorological parameters, ice thickness, ice temperature and light levels in the water column. We used the probe data to develop a physics-based model which simulates the growth and melt of the lake ice over time. On experimenting with different levels of model complexity using model selection criteria, we found that air temperature is by far the dominant variable in such systems, and a model based on temperature alone can calculate ice thickness to a reasonable level of accuracy. This allows predictions of how such lake may respond to long-term global warming scenario.
Mechanist proxies to reconstruct changes in palaeoclimates
Research is focused on quantifying how the Earth’s climate has changed over geologic time, how these changes have influenced the Earth’s terrestrial biosphere and how in turn the Earth’s terrestrial biosphere has influenced climate. This is being achieved through combining palaeobotanical studies with experimental investigations into how plants adapt to environmental change.
Plant responses to CO2
Reconstructing palaeo CO2 concentration using the well characterised inverse relationship between stomatal frequency and atmospheric CO2 using both fossil and living plants.
Plant responses to UV-B radiation
We are developing a new proxy to detect changes in the terrestrial UV-B radiation budget over geologic time using changes in the biochemistry of fossil and extant pollen and spores.
Lability of carbon stored in permafrost peatlands
One third of the global soil carbon is stored in northern peatlands. Today, the organic carbon stored in peatlands in permafrost regions, is under threat from climate warming. If the decomposition rates of the soil organic carbon increases, in response to increased temperature and altered hydrology (due to melting permafrost), potentially large quantities of carbon dioxide could enter the atmosphere. In order to understand the potential feed backs from northern peatlands to the climate system it is essential to understand the mechanisms that control soil organic carbon decomposition rates. Currently, poor information of soil organic carbon chemistry and how it is related to potential carbon loss from high latitude ecosystems limits our ability to understand the fate of this globally important carbon pool. This study combines field measurement of carbon dioxide in subarctic peatlands, laboratory experiments, and sophisticated analysis of the carbon chemistry by solid state 13C NMR to unravel the role of soil carbon chemistry for carbon emissions from permafrost peatlands.
Recovery of ecosystem carbon fluxes and storage from herbivory
The carbon sink strength of arctic tundra is under pressure from increasing populations of arctic breeding geese. In this study we examine how CO2 and CH4 fluxes, plant biomass and soil C responded to the removal of vertebrate herbivores in a high arctic wet moss meadow that has been intensively used by barnacle geese (Branta leucopsis) for ca. 20 years. For this work we use long term grazing exclosures in Ny-Alesund, Spitbergen, were we measure the recovery of the vegetation and the C fluxes following the removal of the grazers. Photo M. Loonen