Nitrogen pollution a threat to British wildflowers

Nitrogen pollution caused by cars, power stations and in agricultural practices is a threat to British wildflowers, experts have warned.

Increased levels of nitrogen in the atmosphere means that the air is over-fertilising the landscape and reducing the variety of different plants found in important habitats across the UK. As levels of nitrogen continue to affect British air quality, flowering plants are becoming continually endangered, replaced by grasses and weeds such as nettles.

Background levels of ozone, a pollutant when it occurs at ground level, have also been found to be having a damaging effect on plants, reducing yields by up to 15 per cent in southern Britain in a typical summer, the study found.

The Centre for Ecology and Hydrology found that even though Britain is no longer the 'dirty man of Europe', increased emissions from across the northern hemisphere are pushing up background pollution.

Controls have been very successful at home, however, where controls on sulphur emissions from coal-fired power stations have slashed the pollutant by 90 per cent since the 1950s. This has started a gradual recovery of some natural environments, with soil quality improving with less acidity, according to the review’s chairman Professor David Fowler.

Mr Fowler said that compared to the 1970s - where the air quality was filthy in the UK because of sulphur pollution - the situation now is much healthier. "You only have to see the air quality across the UK, how clean the air is, to see we’ve made big progress," he said.

However, there needs to be more done to reduce nitrogen pollutants globally, with the US, India and China affecting the UK. Nitrogen can be seen to affect sensitive plants in the countryside, with acid grassland habitats seeing a reduction in flowers such as eyebright, harebell and ribwort plantain when there are high levels of nitrogen, according to the report.

Professor Fowler said: "Those plants which have adapted to a small supply of nitrogen are being out-competed for light and nutrients by rapidly growing species.

"We are changing the natural flora of the country over time. Many grass species out-compete the flowering plants."

Posted by Joseph Hutton