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| Titel |
Impact of forest stand management on temporal dynamics of soil carbon and nitrogen |
| VerfasserIn |
Viktor Bruckman, Shuai Yan, Eduard Hochbichler, Gerhard Glatzel |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250054373
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| Zusammenfassung |
| The quantity and quality of soil organic matter (SOM) strongly influence the biomass
production capacity of forest ecosystems. At present, increased biomass harvesting for
energetic utilisation is a hot topic. The extraction of logging residues, which are left on site in
traditional forest management in Austria, and shortening of rotation periods will potentially
alter carbon (C) and nitrogen (N) mineralization rates and turnover. This study focuses on i)
assessing the influence of different forest management systems for deciduous species on soil
C- and N stores and mineralization potential along a full rotation period and ii) testing
whether silvicultural systems can be used to manage N retention and release. The
chronosequence approach was used to study temporal dynamics of C and N on differently
managed, Quercus petraea dominated forest sites (high forest on eutric cambisol,
11-91years as well as coppice with standards system on haplic chernozem, 1-50years).
Above- and belowground biomass pools as well as belowground organic C- and
total N pools (in five geometric horizons, up to 50cm depth) were estimated by
means of systematic sampling of the soil and use of allometric functions for biomass
pools. C was determined by dry combustion (soil organic carbon (SOC) and N by
Kieldahl digestion (soil total N). SOC pools ranged from 5.3 to 6.9kg.m-2 on eutric
cambisol, representing 43% of total site C stores and from 7.2 to 10.4kg.m-2 on
haplic chernozem, representing 42% respectively. Total N stores in the mineral soil
compartment ranged from 0.36 to 0.45kg.m-2 and from 0.65 to 0.94kg.m-2 for
the two soil types. No significant correlation with stand age was observed for C
and N pools in both study areas. However, C/N ratios as a measure for nitrogen
availability show distinct temporal trends along the chronosequence in differently
managed stands. The high forest system shows a gradual decrease of C/N ratio
with increasing stand age in all horizons while the coppice with standards system
shows a decrease until about half of the rotation period after which it increases
again to the end of the rotation period. Wide C/N ratios at the beginning of rotation
periods indicate rapid mineralization rates after harvesting. In the high forest on
eutric cambisol sites, the C/N ratio is predominantly correlated with C (Pearson
correlation coefficient of R=+0.70, p |
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