We need to talk about Nitrogen

Tim's Grove at Coughton Court

Nitrogen in the air is one of the greatest threats to our wild plants, lichens and fungi, yet few people have even heard about it. Plantlife’s report, We need to talk about Nitrogen, raises the alarm about its devastating impacts.

Plantlife’s report We need to talk about Nitrogen (March 2017) has initiated the long overdue conversation about a neglected environmental issue which is having a significant impact on our habitats and wildlife: atmospheric nitrogen deposition.

In the 2016 State of Nature Report, the major driver of species loss was identified as the intensification of agricultural practice over the last 50 years. Farm fertilisers, transport and power stations are major sources of atmospheric nitrogen. In the last century vast amounts of reactive nitrogen have been emitted into the atmosphere, deriving primarily from agricultural intensification (ammonia) and burning fossil fuels (nitrogen oxides).

This over accumulation in the atmosphere has led to the nitrogen deposition as a pollutant, either from the air (dry deposition) or precipitated (wet deposition).

What does this mean for our wildlife?

In affected areas, species that thrive in nitrogen-rich conditions (such as nettles and cow parsley) increase in abundance and nitrogen sensitive species don’t fare well. This leads to homogenisation of habitats, with the potential to reduce the abundance and diversity of other wildlife such as fungi, insects and birds.

National Trust is a major owner and manager of habitats such as heaths, sand dunes and grasslands on thin soils with low natural fertility that may be harmed by deposition of atmospheric nitrogen.

We’re concerned that the ‘perfect storm’ of climate change-induced longer growing seasons, warmer temperatures and increased CO2, plus the fertilising effect of nitrogen pollution will harm these habitats and the wildlife they support.

What can be done?

On our own land, we have the opportunity, through our Playing our part strategy, to work with our land managers and tenant farmers to improve the condition and increase the size of our wildlife habitats, making more of them and linking them up.  We’re also exploring how we can work with partners, at a landscape-scale, to restore a healthy and beautiful natural environment.

Plantlife are calling for six actions as a result of their report – ranging from government strategies to tackle the impacts of nitrogen emissions; effective monitoring and management of affected areas, and practical support for land managers to reduce emissions; through to greater public awareness of the problem.