Interactive effects of nitrogen deposition and fire on plant and soil chemistry in an alpine heathland.
The response of alpine heathland vegetation and soil chemistry to N additions of 0, 10, 20 and 50 kg N ha(-1) year(-1) in combination with simulated accidental fire (+/-) was monitored over a 5-year period. N addition caused rapid and significant increases in plant tissue N content and N:P and N:K of Calluna vulgaris, suggesting increasing phosphorus and potassium limitation of growth. Soil C:N declined significantly with N addition, indicating N saturation and increasing likelihood of N leakage. Fire further decreased soil C:N and reduced potential for sequestration of additional N. This study shows that alpine heathlands, which occupy the headwaters of many rivers, have limited potential to retain deposited N and may rapidly become N saturated, leaking N into downstream communities and surface waters.
Britton
A J
AJ
Macaulay Institute, Craigiebuckler, Aberdeen AB15 8QH, UK. a.britton@macaulay.ac.uk
Helliwell
R C
RC
Fisher
J M
JM
Gibbs
S
S
D000327:Adsorption; D000393:Air Pollutants / Q000494:pharmacology* / Q000633:toxicity; D029795:Calluna / Q000737:chemistry / Q000254:growth & development* / Q000378:metabolism; D002244:Carbon / Q000032:analysis / Q000378:metabolism; D004463:Ecology / Q000379:methods; D017753:Ecosystem; D005390:Fires; D009584:Nitrogen / Q000494:pharmacology* / Q000633:toxicity; D010758:Phosphorus / Q000032:analysis / Q000378:metabolism; D011188:Potassium / Q000032:analysis / Q000378:metabolism; D012987:Soil / Q000032:analysis; D014874:Water Pollutants, Chemical
D000393:Air Pollutants; D012987:Soil; D014874:Water Pollutants, Chemical; D010758:Phosphorus; D002244:Carbon; D009584:Nitrogen; D011188:Potassium