PHD Project

December 14, 2016

Impact of ozone on nitrogen dynamics of grassland vegetation

Impact of ozone on nitrogen dynamics of grassland vegetation

Ozone pollution has negative effects on many species of semi-natural vegetation, and grasslands have been shown to be particularly sensitive. Nitrogen deposition is also a threat to vegetation and can decrease plant biodiversity. In addition to changes in plant physiology, recent experiments have indicated that ozone alters nitrogen absorption and resorption of nitrogen from leaves prior to senescence. These affect litter quality and could therefore cause secondary pollution problems, as an increased proportion of the deposited nitrogen is either leached into groundwater and streams, or into the atmosphere as N2O or NO2 following microbial conversion. Therefore, ozone is likely to exacerbate impacts of atmospheric nitrogen deposition, causing changes to nutrient cycling and detrimental effects on ecosystem services and functioning via reduced carbon sequestration and increased greenhouse gas release.

You will investigate the nitrogen dynamics of selected grassland vegetation in response to ozone by performing experimental work in the ozone exposure facilities (http://www.ceh.ac.uk/our-science/research-facility/solardomes-and-ozone-field-release-system) at CEH Bangor. In addition to impacts on biogeochemical cycling within the ecosystem, such as impacts on soil and microbial enzymes, this will include impacts of ozone on leaching of nitrogen into groundwater and gaseous N emissions from the soil. The results of these studies will be used to develop a conceptual model of the interactive effects of ozone and nitrogen pollution, highlighting the mechanisms by which ozone pollution could exacerbate the impacts of nitrogen pollution in grassland ecosystems.

You will benefit from postgraduate training schemes available at both CEH and Bangor University, including training in health and safety, statistical analysis, quality assurance, presentation and writing skills. You will become part of a vibrant and prolific research community supervised by experts in plant/soil interactions, biogeochemistry, Ecosystem Services and integrated catchment management.

Applicants should hold a minimum of a UK Honours Degree at 2:1 level or equivalent in a relevant subject such as Environmental Science or Natural Sciences.

For further details please contact Dr Felicity Hayes fhay@ceh.ac.uk or Dr Nathalie Fenner n.fenner@bangor.ac.uk