Diagnostic indicators of elevated nitrogen deposition.
Tissue N content of mosses, which has been shown to be an indicator of enhanced N, was studied at a range of locations dominated either by wet or dry deposited and oxidised and reduced forms of N. Tissue N responded differently to wet and dry deposited N. For a 1 kg ha(-1) y(-1) increase in N deposition, tissue N increased by 0.01% at wet deposition sites but by 0.03% at sites dominated by dry deposited NH3. Tissue N at wet deposition sites responded more to concentrations of NO3- and NH4+ in precipitation (r(2) 0.63) than to total N deposition (r(2) 0.27), concentration explaining 66% of the variation in tissue N, wet deposition 33%. The study clearly concludes that tissue N concentration in mosses provides a good indication of N deposition at sites where deposition is dominated by NH3, and is also valuable in identifying vegetation exposed to large concentrations of NH4+ or NO3-, in wet deposition dominated areas, such as hilltops and wind exposed woodland edges.
Pitcairn
Carole
C
Centre for Ecology and Hydrology Edinburgh, Atmospheric Sciences, Bush Estate, Penicuik, Midlothian EH26 0QB, UK. thepitcairns@yahoo.ac.uk
Fowler
David
D
Leith
Ian
I
Sheppard
Lucy
L
Tang
Sim
S
Sutton
Mark
M
Famulari
Daniela
D
D015258:Acid Rain; D000383:Agriculture; D000392:Air Movements; D000393:Air Pollutants / Q000032:analysis*; D000822:Animal Husbandry; D044002:Bryophyta / Q000737:chemistry*; D004784:Environmental Monitoring / Q000379:methods*; D040362:Geographic Information Systems; D009584:Nitrogen / Q000032:analysis*; D014197:Trees; D006113:United Kingdom
D015258:Acid Rain; D000393:Air Pollutants; D009584:Nitrogen