+ Site Statistics
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

Identification of coniferous forests with incipient nitrogen saturation through analysis of arginine and nitrogen-15 abundance of trees

Journal of Environmental Quality 26(1): 302-309
Identification of coniferous forests with incipient nitrogen saturation through analysis of arginine and nitrogen-15 abundance of trees
Stands of Norway spruce (Picea abies (L.) Karst.) differing in throughfall N deposition and NO-3- leaching were investigated to determine if arginine concentrations and delta-15N abundances of needles could be used to predict NO-3- leaching from stands. Twenty-three stands, all located in southern Sweden, were sampled and five of these had average NO-3- concentrations gt 0.1 mg NO-3-N L-1 in soil water at a 50-cm depth. Arginine concentrations and delta-15N abundances of needles were significantly higher for sites that exhibited NO-3- leaching. The delta-15N enrichment (epsilon), i.e., difference between foliage and soil organic matter in delta-15N, showed less variation than SIN of needles alone in regressions against NO-3- leaching and was, thus, a better predictor of leaching. All sites that exhibited N leaching had arginine concentrations gt 5 mu-mol g dw-1 and epsilon gt -0.5 (%) and thus, there was a strong correlation between arginine and epsilon values. To test if arginine accumulation, as such, can affect the delta-15N of needles, arginine and delta-15N were determined for Scots pine (Pinus sylvestris L.) trees given different amounts of N fertilizer. Although fertilization caused a dramatic increase in arginine concentrations of needles, no immediate change in delta-15N was observed. A hypothesis is proposed to explain the causal linkage between elevated arginine and delta-15N of needles and leaching of N. Thus, arginine accumulation in trees corresponds to decreased uptake rates of NH-4+ leaving NH-4+ ions available for nitrification. During nitrification, discrimination against the heavier 15N takes place resulting in a depleted NO-3- pool and enriched NH-4+ pool. Preferential uptake of NH-4+ by conifer trees will then lead to elevated 15N abundance of needles. It is concluded that N leaching coniferous forests can be identified through analysis of arginine and delta-15N of needles.

Accession: 002863393

Related references

Variations in nitrogen 15 abundance in a forest fertilization trial critical loads of nitrogen nitrogen saturation contamination and effects of revitalization fertilization. Plant & Soil 142(2): 211-219, 1992

Long-term nitrogen additions and nitrogen saturation in two temperate forests. Ecosystems 3(3): 238-253, 2000

A modified nitrogen budget for temperate deciduous forests in an advanced stage of nitrogen saturation. Global Biogeochemical Cycles: 4, Gb4006, 2008

Metabolism of arginine epsilon nitrogen 15 urea nitrogen 15 and ammonium nitrogen 15 in citrus trees citrus unshiu. Journal of the Japanese Society for Horticultural Science 54(1): 26-32, 1985

An assessment of the relationship between potential chemical indices of nitrogen saturation and nitrogen deposition in hardwood forests in southern Ontario. Environmental Monitoring and Assessment 164(1-4): 9-20, 2010

Nitrogen 15 fourier transform nmr spectra of amino acids in natural abundance ph dependence of nitrogen 15 chemical shifts for l arginine. Tetrahedron Letters 20: 1809-1812, 1974

Natural abundance of 15N in nitrogen-limited forests and tundra can estimate nitrogen cycling through mycorrhizal fungi a review. Ecosystems: 5, 815-830, 2008

Variation in natural abundance of nitrogen 15 among plant parts and in nitrogen 15 nitrogen 14 fractionation during nitrogen fixation in the legume rhizobia symbiotic system. Plant & Cell Physiology 27(5): 791-800, 1986

Estimation of symbiotically fixed nitrogen in field grown soybeans an application of natural nitrogen 15 nitrogen 14 abundance and a low level nitrogen 15 tracer technique. Plant & Soil 93(2): 269-286, 1986

Nitrogen dynamics in coniferous forests of Pakistan. Commonwealth Forestry Review 69(1): 55-62, 1990