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| Titel |
What are the main climate drivers for shrub growth in Northeastern Siberian tundra? |
| VerfasserIn |
D. Blok, U. Sass-Klaassen, G. Schaepman-Strub, M. M. P. D. Heijmans, P. Sauren, F. Berendse |
| 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 ; 8, no. 5 ; Nr. 8, no. 5 (2011-05-17), S.1169-1179 |
| Datensatznummer |
250005814
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| Publikation (Nr.) |
 copernicus.org/bg-8-1169-2011.pdf |
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| Zusammenfassung |
| Deciduous shrubs are expected to rapidly expand in the Arctic during the
coming decades due to climate warming. A transition towards more
shrub-dominated tundra may have large implications for the regional surface
energy balance, permafrost stability and carbon storage capacity, with
consequences for the global climate system. However, little information is
available on the natural long-term shrub growth response to climatic
variability. Our aim was to determine the climate factor and time period
that are most important to annual shrub growth in our research site in
NE-Siberia. Therefore, we determined annual radial growth rates in Salix pulchra and
Betula nana shrubs by measuring ring widths. We constructed shrub ring width
chronologies and compared growth rates to regional climate and remotely
sensed greenness data. Early summer temperature was the most important
factor influencing ring width of S. pulchra (Pearson's r = 0.73, p < 0.001) and B. nana
(Pearson's r = 0.46, p < 0.001). No effect of winter precipitation on shrub
growth was observed. In contrast, summer precipitation of the previous year
correlated positively with B. nana ring width (Pearson's r = 0.42, p < 0.01),
suggesting that wet summers facilitate shrub growth in the following growing
season. S. pulchra ring width correlated positively with peak summer NDVI, despite the
small coverage of S. pulchra shrubs (< 5 % surface cover) in our research area. We
provide the first climate-growth study on shrubs for Northeast Siberia, the
largest tundra region in the world. We show that two deciduous shrub species
with markedly different growth forms have a similar growth response to
changes in climate. The obtained shrub growth response to climate
variability in the past increases our understanding of the mechanisms
underlying current shrub expansion, which is required to predict future
climate-driven tundra vegetation shifts. |
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