ISSN:
1573-2932
Keywords:
nitrogen deposition
;
montane forest
;
Picea abies
;
N-15 isotope
;
nitrate leaching
Source:
Springer Online Journal Archives 1860-2000
Topics:
Energy, Environment Protection, Nuclear Power Engineering
Notes:
Abstract Nitrogen (N) was added over two years to a spruce-dominated (Picea abies) montane forest at Alptal, central Switzerland. A solution of ammonium nitrate (NH4NO2) was frequently sprinkled on the forest floor (1500 m2) to simulate an additional input of 30 kg N ha-1 yr-1 over the ambient 12 kg bulk inorganic N deposition. The added nitrogen was labelled with 15NH4 15NO3 during the first year. Results are compared to a control plot. Neither the trees nor the ground vegetation showed any increase in their N content. Only 4.1% of N in the ground vegetation came from the N addition. Current-year needles contained 11 mg N g-1 dry weight, of which only 2% was from labelled N; older needles had approximately half as much 15N. The uptake from the treatment was therefore very small. Redistribution of N also took place in the trunks: 1 to 2-year-old wood contained 0.7% labelled N, tree rings dating back 3 to 14 years contained 0.4%. Altogether, the above-ground vegetation took up 12% of the labelled N. Most 15N was recovered in the soil: 13% in litter and roots, 63% in the sieved soil. Nitrate leaching accounted for 10%. Factors thought to be influencing N uptake are discussed in relation to plant use of N and soil conditions.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1005206927764
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