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| Titel |
Estimating global carbon uptake by lichens and bryophytes with a process-based model |
| VerfasserIn |
P. Porada, B. Weber, W. Elbert, U. Pöschl, A. Kleidon |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 10, no. 11 ; Nr. 10, no. 11 (2013-11-05), S.6989-7033 |
| Datensatznummer |
250085397
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| Publikation (Nr.) |
 copernicus.org/bg-10-6989-2013.pdf |
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| Zusammenfassung |
| Lichens and bryophytes are abundant globally and they may even form the
dominant autotrophs in (sub)polar ecosystems, in deserts and at high
altitudes. Moreover, they can be found in large amounts as epiphytes in
old-growth forests. Here, we present the first process-based model which
estimates the net carbon uptake by these organisms at the global scale, thus
assessing their significance for biogeochemical cycles. The model uses
gridded climate data and key properties of the habitat (e.g. disturbance
intervals) to predict processes which control net carbon uptake, namely
photosynthesis, respiration, water uptake and evaporation. It relies on
equations used in many dynamical vegetation models, which are combined with
concepts specific to lichens and bryophytes, such as poikilohydry or the
effect of water content on CO2 diffusivity. To incorporate the great
functional variation of lichens and bryophytes at the global scale, the model
parameters are characterised by broad ranges of possible values instead of a
single, globally uniform value. The predicted terrestrial net uptake of 0.34
to 3.3 Gt yr−1 of carbon and global patterns of productivity are in
accordance with empirically-derived estimates. Considering that the
assimilated carbon can be invested in processes such as weathering or
nitrogen fixation, lichens and bryophytes may play a significant role in
biogeochemical cycles. |
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