Linkages between N turnover and plant community structure in a tundra landscape
Björk, Robert G. ; Klemedtsson, Leif ; Molau, Ulf ; Harndorf, Jan ; Ödman, Anja LU
and Giesler, Reiner
(2007)
In Plant and Soil
294(1-2).
p.247-261
- Abstract
The spatial distribution of organic soil nitrogen (N) in alpine tundra was studied along a natural environmental gradient, covering five plant communities, at the Latnjajaure Field Station, northern Swedish Lapland. The five communities (mesic meadow, meadow snowbed, dry heath, mesic heath, and heath snowbed) are the dominant types in this region and are differentiated by soil pH. Net N mineralization, net ammonification, and net nitrification were measured using 40-day laboratory incubations based on extractable NH 4 + and NO 3 - . Nitrification enzyme activity (NEA), denitrification enzyme activity (DEA), amino acid concentrations, and microbial respiration were measured for soils from each... (More)
The spatial distribution of organic soil nitrogen (N) in alpine tundra was studied along a natural environmental gradient, covering five plant communities, at the Latnjajaure Field Station, northern Swedish Lapland. The five communities (mesic meadow, meadow snowbed, dry heath, mesic heath, and heath snowbed) are the dominant types in this region and are differentiated by soil pH. Net N mineralization, net ammonification, and net nitrification were measured using 40-day laboratory incubations based on extractable NH 4 + and NO 3 - . Nitrification enzyme activity (NEA), denitrification enzyme activity (DEA), amino acid concentrations, and microbial respiration were measured for soils from each plant community. The results show that net N mineralization rates were more than three times higher in the meadow ecosystems (mesic meadow 0.7 μg N g -1 OM day-1 and meadow snowbed 0.6 μg N g-1 OM day-1) than the heath ecosystems (dry heath 0.2 μg N g -1 OM day-1, mesic heath 0.1 μg N g-1 OM day-1 and heath snowbed 0.2 μg N g-1 OM day -1). The net N mineralization rates were negatively correlated to organic soil C/N ratio (r = -0.652, P < 0.001) and positively correlated to soil pH (r = 0.701, P < 0.001). Net nitrification, inorganic N concentrations, and NEA rates also differed between plant communities; the values for the mesic meadow were at least four times higher than the other plant communities, and the snowbeds formed an intermediate group. Moreover, the results show a different pattern of distribution for individual amino acids across the plant communities, with snowbeds tending to have the highest amino acid N concentrations. The differences between plant communities along this natural gradient also illustrate variations between the dominant mycorrhizal associations in facilitating N capture by the characteristic functional groups of plants.
(Less)
- author
- Björk, Robert G.
; Klemedtsson, Leif
; Molau, Ulf
; Harndorf, Jan
; Ödman, Anja
LU
and Giesler, Reiner
- publishing date
- 2007-05-01
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Amino acids, Environmental gradient, Microbially available nitrogen, Mineralization, Nitrification, Spatial variation
- in
- Plant and Soil
- volume
- 294
- issue
- 1-2
- pages
- 247 - 261
- publisher
- Springer
- external identifiers
-
- scopus:34249041250
- ISSN
- 0032-079X
- DOI
- 10.1007/s11104-007-9250-4
- language
- English
- LU publication?
- no
- id
- eef927b3-7b60-4c10-aaed-1c284ca17e17
- date added to LUP
- 2019-08-29 17:08:43
- date last changed
- 2022-04-10 20:47:12
@article{eef927b3-7b60-4c10-aaed-1c284ca17e17,
abstract = {{<p>The spatial distribution of organic soil nitrogen (N) in alpine tundra was studied along a natural environmental gradient, covering five plant communities, at the Latnjajaure Field Station, northern Swedish Lapland. The five communities (mesic meadow, meadow snowbed, dry heath, mesic heath, and heath snowbed) are the dominant types in this region and are differentiated by soil pH. Net N mineralization, net ammonification, and net nitrification were measured using 40-day laboratory incubations based on extractable NH <sub>4</sub> <sup>+</sup> and NO <sub>3</sub> <sup>-</sup> . Nitrification enzyme activity (NEA), denitrification enzyme activity (DEA), amino acid concentrations, and microbial respiration were measured for soils from each plant community. The results show that net N mineralization rates were more than three times higher in the meadow ecosystems (mesic meadow 0.7 μg N g <sup>-1</sup> OM day<sup>-1</sup> and meadow snowbed 0.6 μg N g<sup>-1</sup> OM day<sup>-1</sup>) than the heath ecosystems (dry heath 0.2 μg N g <sup>-1</sup> OM day<sup>-1</sup>, mesic heath 0.1 μg N g<sup>-1</sup> OM day<sup>-1</sup> and heath snowbed 0.2 μg N g<sup>-1</sup> OM day <sup>-1</sup>). The net N mineralization rates were negatively correlated to organic soil C/N ratio (r = -0.652, P < 0.001) and positively correlated to soil pH (r = 0.701, P < 0.001). Net nitrification, inorganic N concentrations, and NEA rates also differed between plant communities; the values for the mesic meadow were at least four times higher than the other plant communities, and the snowbeds formed an intermediate group. Moreover, the results show a different pattern of distribution for individual amino acids across the plant communities, with snowbeds tending to have the highest amino acid N concentrations. The differences between plant communities along this natural gradient also illustrate variations between the dominant mycorrhizal associations in facilitating N capture by the characteristic functional groups of plants.</p>}},
author = {{Björk, Robert G. and Klemedtsson, Leif and Molau, Ulf and Harndorf, Jan and Ödman, Anja and Giesler, Reiner}},
issn = {{0032-079X}},
keywords = {{Amino acids; Environmental gradient; Microbially available nitrogen; Mineralization; Nitrification; Spatial variation}},
language = {{eng}},
month = {{05}},
number = {{1-2}},
pages = {{247--261}},
publisher = {{Springer}},
series = {{Plant and Soil}},
title = {{Linkages between N turnover and plant community structure in a tundra landscape}},
url = {{http://dx.doi.org/10.1007/s11104-007-9250-4}},
doi = {{10.1007/s11104-007-9250-4}},
volume = {{294}},
year = {{2007}},
}