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Titel |
The response of Picea crassifolia forest to climate warming |
VerfasserIn |
Zhibin He, Jun Du, Junjun Yang, Longfei Chen, Xi Zhu |
Konferenz |
EGU General Assembly 2014
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Medientyp |
Artikel
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Sprache |
Englisch
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Digitales Dokument |
PDF |
Erschienen |
In: GRA - Volume 16 (2014) |
Datensatznummer |
250088239
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Publikation (Nr.) |
EGU/EGU2014-2326.pdf |
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Zusammenfassung |
Picea crassifolia forest, an endemic genus mainly distributing in the Qilian Mountain of
Northwest China, is very sensitive to climate warming. In the present study, the response of
treeline, phenological period, and sap flow of P. crassifolia forest to climate warming were
analyzed though a set of observations and experiments. The result showed: (1) During the
past 50 years, the temperature had raised at a mean rate of 0.29°C per decade in
this region, especially since 1980s (had increased by a total of more than 1.25Ë
C), obviously higher than increment degree IPCC reported. This resulted in the
increase of tree recruitment which was significantly positively correlated with the
mean growing season temperature and with the mean minimum temperature in June
and in winter. Treeline elevation shifted upward by 5.7 to 13.6 m from 1907 to
1957 and by 6.1 to 10.4 m after 1957. (2) By quantifying the canopy phenology
events based on satellite-derived datasets (MODIS-NDVI) from 2001 to 2011, and
investigating the correlation with climate factors, a conclusion had been drawn
which revealed a 3.7 days/decade advance in the length of growing season. Our
results suggested that temperature controlled treeline dynamics and phenological
period more strongly than precipitation in the Qilian Mountains. (3) In the case of
experimental warming (mean daily temperature was increased 0.83°C, mean daily
maximum temperature was increased 4.7°C), the trend for the mass growth of P.
crassifolia sapling presented a notable increase under conditions of warming, especially
for tree height. The data of sap flow showed that warming facilitated the sap flow
of sapling in the end of growing season, which indicated the temperature was a
major restriction to sap flow rate, especially in the condition of lower temperature. |
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