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| Titel |
Land surface phenological response to decadal climate variability across Australia using satellite remote sensing |
| VerfasserIn |
M. Broich, A. Huete, M. G. Tulbure, X. Ma, Q. Xin, M. Paget, N. Restrepo-Coupe, K. Davies, R. Devadas, A. Held |
| 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. 18 ; Nr. 11, no. 18 (2014-09-29), S.5181-5198 |
| Datensatznummer |
250117611
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| Publikation (Nr.) |
 copernicus.org/bg-11-5181-2014.pdf |
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| Zusammenfassung |
Land surface phenological cycles of vegetation greening and browning are
influenced by variability in climatic forcing. Quantitative spatial
information on phenological cycles and their variability is important for
agricultural applications, wildfire fuel accumulation, land management, land
surface modeling, and climate change studies. Most phenology studies have
focused on temperature-driven Northern Hemisphere systems, where phenology
shows annually recurring patterns. However, precipitation-driven non-annual
phenology of arid and semi-arid systems (i.e., drylands) received much less
attention, despite the fact that they cover more than 30% of the global
land surface. Here, we focused on Australia, a continent with one of the most
variable rainfall climates in the world and vast areas of dryland systems,
where a detailed phenological investigation and a characterization of the
relationship between phenology and climate variability are missing.
To fill this knowledge gap, we developed an algorithm to characterize
phenological cycles, and analyzed geographic and climate-driven variability
in phenology from 2000 to 2013, which included extreme drought and wet years.
We linked derived phenological metrics to rainfall and the Southern
Oscillation Index (SOI). We conducted a continent-wide investigation and a
more detailed investigation over the Murray–Darling Basin (MDB), the primary
agricultural area and largest river catchment of Australia.
Results showed high inter- and intra-annual variability in phenological
cycles across Australia. The peak of phenological cycles occurred not only
during the austral summer, but also at any time of the year, and their timing
varied by more than a month in the interior of the continent. The magnitude
of the phenological cycle peak and the integrated greenness were most
significantly correlated with monthly SOI within the preceding 12 months.
Correlation patterns occurred primarily over northeastern Australia and
within the MDB, predominantly over natural land cover and particularly in
floodplain and wetland areas. Integrated greenness of the phenological cycles
(surrogate of vegetation productivity) showed positive anomalies of more than
2 standard deviations over most of eastern Australia in 2009–2010, which
coincided with the transition from the El Niño-induced decadal droughts
to flooding caused by La Niña. |
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