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| Titel |
Pasture degradation modifies the water and carbon cycles of the Tibetan highlands |
| VerfasserIn |
W. Babel, T. Biermann, H. Coners, E. Falge, E. Seeber, J. Ingrisch, P.-M. Schleuß, T. Gerken, J. Leonbacher, T. Leipold, S. Willinghöfer, K. Schützenmeister, O. Shibistova, L. Becker, S. Hafner, S. Spielvogel, X. Li, X. Xu, Y. Sun, L. Zhang, Y. Yang, Y. Ma, K. Wesche, H.-F. Graf, C. Leuschner, G. Guggenberger, Y. Kuzyakov, G. Miehe, T. Foken |
| 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 ; 11, no. 23 ; Nr. 11, no. 23 (2014-12-02), S.6633-6656 |
| Datensatznummer |
250117707
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| Publikation (Nr.) |
 copernicus.org/bg-11-6633-2014.pdf |
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| Zusammenfassung |
| The Tibetan Plateau has a significant role with regard to atmospheric circulation and the monsoon
in particular. Changes between a closed plant cover and open bare soil are one of the striking
effects of land use degradation observed with unsustainable range management or climate change,
but experiments investigating changes of surface properties and processes
together with atmospheric feedbacks
are rare and have not been undertaken in the world's two largest alpine ecosystems, the alpine
steppe and the Kobresia pygmaea pastures of the Tibetan Plateau. We
connected measurements
of micro-lysimeter, chamber, 13C labelling, and eddy covariance and combined the
observations with land surface and atmospheric models, adapted to the highland conditions. This
allowed us to analyse how three degradation stages affect the water and carbon cycle of pastures
on the landscape scale within the core region of the Kobresia pygmaea ecosystem. The
study revealed that increasing degradation of the Kobresia turf affects carbon allocation
and strongly reduces the carbon uptake, compromising the function of Kobresia pastures as
a carbon sink. Pasture degradation leads to a shift from transpiration to evaporation while
a change in the sum of
evapotranspiration over a longer period cannot be confirmed. The results show an earlier onset of
convection and cloud generation, likely triggered by a shift in
evapotranspiration timing when dominated by evaporation. Consequently,
precipitation starts earlier and clouds decrease the incoming solar radiation. In summary, the
changes in surface properties by pasture degradation found on the highland have a significant
influence on larger scales. |
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