A field ammonia (NH) release experiment and open top chambers containing moorland monoliths continuously fumigated with NH or sprayed with NHCl were used to assess the potential for using δN values in determining the area of influence around a point NH emission source δN values are being increasingly used as environmental tracers and we tested the hypothesis that the δN signal from an NH emission source is observable in nearby vegetation. Using modified monitoring devices, atmospheric NH concentrations were found to decrease with distance from source, with δN values also reflecting this trend, producing a signal shift with changing concentration. Open top chamber studies of δN values of Calluna vulgaris (L.) Hull indicated a correlation with deposition treatments in current year shoots. Analysis of Calluna shoots from the NH release showed a similar trend of δN enrichment. Significant linear correlations between δN and percent N in plant material were found, both in the controlled conditions of the open top chambers and at the NH release site, illustrating the possible use of this technique in N deposition biomonitoring.