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| Titel |
Woody Biomass and Carbon Stocks of Natural vs. Restored Mountain Birch (Betula pubescens, Ehrh.) Woodlands in South Iceland |
| VerfasserIn |
Matthias Hunziker, Bjarni D. Sigurdsson, Guðmundur Halldórsson, Nikolaus J. Kuhn |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250044643
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| Zusammenfassung |
| Following a period of land degradation lasting more than one thousand years, Iceland has
been undertaken ambitious restoration and afforestation efforts for one century now.
Afforestation has also been a central venture of the Icelandic government in order to meet the
commitments assigned by the Kyoto Protocol because vegetation represents an important
carbon sink. Yet, currently little is known on how much carbon is sequestrated effectively in
afforested Icelandic woody ecosystems. In order to fill this knowledge gap the “KolBjörk”
(CarbBirch), a three year (2008-2011) Icelandic ecosystem research project, was
launched.
In this project the development of key ecosystem factors are studied in a chronosequence
study of restored birch woodlands, ranging from 0-60 years in age. These factors are: a) forest
growth, b) plant communities, c) soil biota, d) soil chemistry and physics and e) carbon
stocks and fluxes. Restored woodlands are compared with: a) eroded land, representing the
status of the area before restoration and b) original birch woodlands. The aim of present study
which is part of “KolBjörk” was to estimate the above-and belowground woody biomass and
carbon stocks of old native birch (Betula pubescens) vs. restored birch woodlands in South
Iceland.
In summer 2009 31 trees (0.1-5.5m height) were measured and excavated and tree inventories
(n=519) were established. The excavated trees formed the dataset to establish allometric
biomass functions for young, afforested Icelandic mountain birch. The functions were
statistically fitted using numerical nonlinear regression using Matlab. Subsequently, forest
biomass and carbon stock of the four different old sites were estimated by the newly
developed allometric relationships.
The age of the four sites is 10, 15, 60 and 80 years, respectively, while the 80-yr old
stand represents a natural grown forest, the others are replanted. The total C-stock
in the 10-yr old birch stand was 2.0 Mg/ha, in the 15-yr old 11.0 Mg/ha, in the
60-yr old 87.4 Mg/ha and in the 80-yr old 38.7 Mg/ha. The ratio between long-time
aboveground and belowground C-stock increases along the chronosequence from 2:1 to
3:1.
Generally, the results are comparable to studies about other tree species. However, the date
collected in this study give a better understanding of the carbon sequestration in Nordic
afforested areas. |
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