Former Ironbridge power station Picture Alexandra Cunha

Power stations are among the sources of nitrogen oxide emissions. Pictured are the former cooling towers at Ironbridge, recently demolished  Photo: Alexandra Cunha

Research led by the UK Centre for Ecology & Hydrology is exploring options for protecting habitats and species that are vulnerable to increases in atmospheric nitrogen pollution.

The Nitrogen Futures project is being carried out for the Joint Nature Conservation Committee (JNCC), the public body that advises the UK’s Government and devolved administrations on UK-wide and international nature conservation issues. Funded by the Department for the Environment, Food and Rural Affairs (Defra), the findings will inform policy development at UK, national and local scale.

The project aims to address the environmental impacts of nitrogen pollution from the air, which is a major driver of biodiversity loss in the UK. Around 60% of the UK’s protected conservation sites and 17% (42,400 km2) of the UK’s total landmass are threatened by damaging levels of excess atmospheric nitrogen.

A variety of human activities such as fertiliser use, livestock rearing, road traffic emissions, waste processing, and energy generation release nitrogen into the air, in the form of either ammonia or nitrogen oxides, depending on the source. It is then subsequently dispersed and deposited on land, lakes and rivers and the sea.

Dr Ulli Dragosits of the UK Centre for Ecology & Hydrology (UKCEH), who is lead scientist on the Nitrogen Futures project, says: “Nitrogen pollution has a cascading, negative impact on biodiversity, and the decline of sensitive species on land and in water ecosystems results in a series of knock-on effects on plants and the animals that rely on them for food.

“The project provides a real opportunity to test various possible future policy options for their impact on the environment and help to identify potential solutions for the future health of our environment.” 

Once within a sensitive ecosystem, excess nitrogen affects its ecological functions, mainly by allowing nitrogen-tolerant plants to out-compete key sensitive species. This results in negative impacts on the plants themselves or animals within the food web, including vegetation change, local extinction, increased sensitivity to frost, drought or diseases.

Nitrogen pollution has a cascading, negative impact on biodiversity - Dr Ulli Dragosits

Nitrogen Futures will bring together available data on nitrogen emissions and estimate the benefits of different possible policy options to reduce pollution and improve people’s health and nature conservation.

Researchers will quantify the effects of introducing targeted mitigation measures near conservation areas to maximise benefits to ecosystems, priority habitats and designated sites. Targeted measures to reduce nitrogen deposition have been shown to provide larger benefit than the same amount of emission reductions spread randomly across a larger geographical area.

As part of this project, the researchers will test possible local measures to reduce and mitigate nitrogen pollution, for example:

  • introducing low emission ‘buffer zones’ around protected sites;
  • planting trees to recapture airborne nitrogen;
  • initiatives to target pollution from transport and combustion sources, such as Clean Air Zones
  • reduction in emissions from power generation and industry, including the use of catalytic reduction technology.

The Nitrogen Futures project is run by JNCC in partnership with Defra, the UK’s devolved administrations as well as Natural England, Natural Resources Wales, Scottish Natural Heritage and the Northern Ireland Environment Agency.

It is being undertaken by a consortium led by UKCEH in collaboration with Rothamsted Research, Aether, Air Quality Consultants (AQC), Lancaster University and Manchester Metropolitan University. Results are expected in spring 2020.

To learn more about this project, the organisations contributing to it and how to get involved, please contact JNCC.

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