 |
| Titel |
Increased winter soil temperature variability enhances nitrogen cycling and soil biotic activity in temperate heathland and grassland mesocosms |
| VerfasserIn |
J. Schuerings, A. Jentsch, V. Hammerl, K. Lenz, H. A. L. Henry, A. V. Malyshev, J. Kreyling |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 11, no. 23 ; Nr. 11, no. 23 (2014-12-12), S.7051-7060 |
| Datensatznummer |
250117734
|
| Publikation (Nr.) |
 copernicus.org/bg-11-7051-2014.pdf |
|
|
|
|
|
| Zusammenfassung |
Winter air temperatures are projected to increase in the temperate zone,
whereas snow cover is projected to decrease, leading to increased soil
temperature variability, and potentially to changes in nutrient cycling.
Here, we experimentally evaluated the effects of increased winter soil
temperature variability on selected aspects of the N-cycle in mesocosms
containing different plant community compositions. The experiment was
replicated at two sites, a colder mountainous upland site with high snow
accumulation and a warmer and drier lowland site.
Increased soil temperature variability enhanced soil biotic activity for both
sites during winter, as indicated by 35% higher nitrogen (N)
availability in the soil solution, 40% higher belowground decomposition
and a 25% increase in the potential activity of the enzyme
cellobiohydrolase. The mobilization of N differed between sites, and the
15N signal in leaves was reduced by 31% in response to winter
warming pulses, but only at the cold site, with significant reductions
occurring for three of four tested plant species at this site. Furthermore,
there was a trend of increased N leaching in response to the recurrent winter
warming pulses.
Overall, projected winter climate change in the temperate zone, with less
snow and more variable soil temperatures, appears important for shifts in
ecosystem functioning (i.e. nutrient cycling). While the effects of warming
pulses on plant N mobilization did not differ among sites, reduced plant
15N incorporation at the colder temperate site suggests that frost
damage may reduce plant N uptake in a warmer world, with important
implications for nitrogen cycling and nitrogen losses from ecosystems. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|