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Titel |
Trends and climatic sensitivities of vegetation phenology in semiarid and arid ecosystems in the US Great Basin during 1982–2011 |
VerfasserIn |
G. Tang, J. A. Arnone, P. S. J. Verburg, R. L. Jasoni, L. Sun |
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 ; 12, no. 23 ; Nr. 12, no. 23 (2015-12-07), S.6985-6997 |
Datensatznummer |
250118194
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Publikation (Nr.) |
copernicus.org/bg-12-6985-2015.pdf |
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Zusammenfassung |
We quantified the temporal trend and climatic sensitivity of vegetation
phenology in dryland ecosystems in the US Great Basin during 1982–2011.
Our results indicated that vegetation greenness in the Great Basin increased
significantly during the study period, and this positive trend occurred in
autumn but not in spring and summer. Spatially, increases in vegetation
greenness were more apparent in the northwestern, southeastern, and eastern
Great Basin but less apparent in the central and southwestern Great Basin.
In addition, the start of growing season (SOS) was not advanced while the
end of growing season (EOS) was delayed significantly at a rate of 3.0 days
per decade during the study period. The significant delay in EOS and lack of
earlier leaf onset caused growing season length (GSL) to increase at a rate
of 3.0 days per decade. Interestingly, we found that the interannual
variation of mean vegetation greenness calculated for the period of March to
November (spring, summer, and autumn – SSA) was not significantly correlated with mean surface air
temperature in SSA but was strongly correlated with total precipitation. On
a seasonal basis, the variation of mean vegetation greenness in spring,
summer, and autumn was mainly attributable to changes in pre-season
precipitation in winter and spring. Nevertheless, climate warming appeared
to play a strong role in extending GSL that, in turn, resulted in the upward
trend in mean vegetation greenness. Overall, our results suggest that
changes in wintertime and springtime precipitation played a stronger role
than temperature in affecting the interannual variability of vegetation
greenness, while climate warming was mainly responsible for the upward trend
in vegetation greenness we observed in Great Basin dryland ecosystems during
the 30-year period from 1982 to 2011. |
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