Vegetation Type Affects the Relationship Between Soil Carbon to Nitrogen Ratio and Nitrogen Leaching
- E. C. RoweAffiliated withCentre for Ecology and Hydrology, Orton Building Email author
- , C. D. EvansAffiliated withCentre for Ecology and Hydrology, Orton Building
- , B. A. EmmettAffiliated withCentre for Ecology and Hydrology, Orton Building
- , B. ReynoldsAffiliated withCentre for Ecology and Hydrology, Orton Building
- , R. C. HelliwellAffiliated withMacaulay Institute
- , M. C. CoullAffiliated withMacaulay Institute
- , C. J. CurtisAffiliated withEnvironmental Change Research Centre, University College London
Rent the article at a discountRent now
* Final gross prices may vary according to local VAT.Get Access
Nitrate leaching occurs when the soil's nitrogen immobilisation and plant uptake capacity has been saturated. Several widely-used models of nitrogen saturation incorporate a breakthrough function in which N begins to be leached at C/N values below an upper threshold, and is completely leached at C/N values below a lower threshold. In a survey of deciduous and coniferous woodland, acid grassland and heathland sites for which both C/N and nitrate flux measurements were available, deciduous woodland and acid grassland typically had lower C/N ratios, and began leaching nitrate at a lower C/N ratio, than coniferous woodland and heathland. Least-square fits of nitrate breakthrough functions gave upper thresholds (no nitrate leaching) of 27 mol C mol−1 N for deciduous woodland and acid grassland and 50 mol C mol−1 N for coniferous woodland and heathland. Upper thresholds were similar, at 24 and 51 mol C mol−1 N, respectively, for total inorganic N (NH4 + NO3) leaching flux as a proportion of total inorganic N influx. In conifer plantations, stand maturity had a large effect, suggesting that a breakthrough function is unsuitable for modelling systems that are in disequilibrium. However, there was sufficient evidence to suggest that using different breakthrough C/N thresholds for different groups of vegetation would improve predictions of N saturation and leaching at both plot and catchment scales. The difference may be related to the reactivity of soil carbon; soils with a large proportion of recalcitrant carbon are likely to begin leaching nitrate at a higher C/N value than soils with more labile carbon.
Keywordsdeposition eutrophication forestry grassland heathland pollution retention
- Vegetation Type Affects the Relationship Between Soil Carbon to Nitrogen Ratio and Nitrogen Leaching
Water, Air, and Soil Pollution
Volume 177, Issue 1-4 , pp 335-347
- Cover Date
- Print ISSN
- Online ISSN
- Kluwer Academic Publishers
- Additional Links
- Industry Sectors
- Author Affiliations
- 1. Centre for Ecology and Hydrology, Orton Building, Deiniol Road, Bangor, Gwynedd, LL57 2UP, U.K.
- 2. Macaulay Institute, Aberdeen, AB15 8QH, U.K.
- 3. Environmental Change Research Centre, University College London, London, WC1H 0AP, U.K.