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Titel |
Do successive climate extremes weaken the resistance of plant communities? An experimental study using plant assemblages |
VerfasserIn |
F. E. Dreesen, H. J. Boeck, I. A. Janssens, I. Nijs |
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. 1 ; Nr. 11, no. 1 (2014-01-08), S.109-121 |
Datensatznummer |
250117107
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Publikation (Nr.) |
copernicus.org/bg-11-109-2014.pdf |
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Zusammenfassung |
The probability that plant communities undergo successive climate extremes
increases under climate change. Exposure to an extreme event might elicit
acclimatory responses and thereby greater resistance to a subsequent event,
but might also reduce resistance if the recovery period is too short or
resilience too low. Using experimental herbaceous plant assemblages, we
compared the effects of two successive extremes occurring in one growing
season (either two drought extremes, two heat extremes or two drought +
heat extremes) to those of assemblages being exposed only to the second
extreme. Additionally, the recovery period between the successive extremes
was varied (2, 3.5 or 6 weeks).
Among the different types of climate extremes, combined heat + drought
extremes induced substantial leaf mortality and plant senescence, while the
effects of drought and heat extremes were smaller. Preceding drought +
heat extremes lowered the resistance in terms of leaf survival to a
subsequent drought + heat extreme if the recovery period was two weeks, even
though the leaves had completely recovered during that interval. No reduced
resistance to subsequent extremes was recorded with longer recovery times or
with drought or heat extremes. Despite the substantial mortality on the
short term, the drought + heat and the heat extremes increased the
end-of-season aboveground biomass independent of the number of extreme
events or the duration of the recovery period. These results show that
recurrent climate extremes with short time intervals can weaken the
resistance of herbaceous plant assemblages. This negative effect in the
short term can, however, be compensated in the longer term through rapid
recovery and secondary positive effects. |
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