In a drive to gain a better understanding of nitrogen effects on protected areas, the Nitrogen Deposition Decision Framework was developed. This brings together national modelling of nitrogen deposition rates with the results of site monitoring to determine whether nitrogen is having an adverse impact on the condition of habitats.
This project aimed to test and validate the Framework using data from studies of vegetation change across 12 Scottish habitats. Analysis showed changes in vegetation composition and diversity over a 40-50 year period and found significant relationships between indicators of vegetation change and nitrogen deposition. The report recommends further work to strengthen the Framework focusing on three key areas:
- To better understand the ‘tipping point’ at which nitrogen deposits on a protected area cause changes in its vegetation composition and diversity.
- To find reliable and cost-effective ways of determining nitrogen deposition rates on sites.
- To incorporate these improved indicators of nitrogen impacts into the routine monitoring and condition assessments for protected areas.