Use of nitrogen to phosphorus ratios in plant tissue as an indicator of nutrient limitation and nitrogen saturation
Article first published online: 2 JUN 2003
Journal of Applied Ecology
Volume 40, Issue 3, pages 523–534, June 2003
How to Cite
Tessier, J. T. and Raynal, D. J. (2003), Use of nitrogen to phosphorus ratios in plant tissue as an indicator of nutrient limitation and nitrogen saturation. Journal of Applied Ecology, 40: 523–534. doi: 10.1046/j.1365-2664.2003.00820.x
- Issue published online: 2 JUN 2003
- Article first published online: 2 JUN 2003
- Received 21 May 2002; final copy received 5 February 2003
- Catskill Mountains;
- herb layer;
- understorey vegetation
- 1Ratios of nitrogen to phosphorus (N:P) in plant foliage have been used to assess nutrient limitation in wetland ecosystems and to indicate nitrogen saturation. Extension of this application to ecosystems other than wetlands remains to be evaluated.
- 2We compared published N:P ratios as thresholds of nutrient limitation with published accounts from nutrient-addition experiments and the N:P ratios of understorey vegetation (Acer spp., Dryopteris intermedia, Erythronium americanum, Lycopodium lucidulum, Oxalis acetosella and Viola macloskeyi) from the Catskill Mountains of New York State, USA. We also performed a nutrient-addition experiment to test the response of these understorey plant species to inputs of N and P.
- 3N:P ratios of Catskill understorey species indicated they were at or near P limitation relative to N:P ratios from other upland ecosystems. Our experiment supported this finding in that none of the species responded to N addition but all increased in P concentration and one increased in biomass with added P. Collectively, these results suggest that the understorey vegetation of the Catskill Mountains is not nitrogen limited, providing further evidence that hardwood forests in this area are nitrogen-saturated.
- 4Synthesis and applications. This study demonstrates that N:P ratios can be effective predictors of nutrient limitation in upland ecosystems. Therefore N:P ratios can be used for management and monitoring purposes in considering the nutrient status of upland ecosystems with particular relevance to the continued deposition of elevated atmospheric N and to the diagnosis of nitrogen saturation.