 |
| Titel |
Organic matter composition and stabilization in a polygonal tundra soil of the Lena Delta |
| VerfasserIn |
S. Höfle, J. Rethemeyer, C. W. Mueller, S. John |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 10, no. 5 ; Nr. 10, no. 5 (2013-05-08), S.3145-3158 |
| Datensatznummer |
250018243
|
| Publikation (Nr.) |
 copernicus.org/bg-10-3145-2013.pdf |
|
|
|
|
|
| Zusammenfassung |
| This study investigated soil organic matter (OM) composition of differently
stabilized soil OM fractions in the active layer of a polygonal tundra soil
in the Lena Delta, Russia, by applying density and particle size
fractionation combined with qualitative OM analysis using solid state
13C nuclear magnetic resonance spectroscopy, and lipid analysis combined
with 14C analysis. Bulk soil OM was mainly composed of plant-derived,
little-decomposed material with surprisingly high and strongly increasing
apparent 14C ages with active layer depth suggesting slow microbial OM
transformation in cold climate. Most soil organic carbon was stored in clay
and fine-silt fractions (< 6.3 μm), which were composed of
little-decomposed plant material, indicated by the dominance of long
n-alkane and n-fatty acid compounds and low alkyl/O-alkyl C ratios.
Organo-mineral associations, which are suggested to be a key mechanism of OM
stabilization in temperate soils, seem to be less important in the active
layer as the mainly plant-derived clay- and fine-silt-sized OM was
surprisingly "young", with 14C contents similar to the bulk soil
values. Furthermore, these fractions contained less organic carbon compared
to density fractionated OM occluded in soil aggregates – a further important
OM stabilization mechanism in temperate soils restricting accessibility of
microorganisms. This process seems to be important at greater active layer
depth where particulate OM, occluded in soil aggregates, was "older" than
free particulate OM. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|