 |
| Titel |
Responses of spring phenology to climate warming reduced over the past decades |
| VerfasserIn |
Yongshuo. H Fu, Hongfang Zhao, Shilong Piao, Marc Peaucelle, Shushi Peng, Guiyun Zhou, Philippe Ciais, Mengtian Huang, Annette Menzel, Josep Peñuelas, Yang Song, Yann Vitasse, Zhenzhong Zeng, Ivan A. Janssens |
| Konferenz |
EGU General Assembly 2016
|
| Medientyp |
Artikel
|
| Sprache |
en
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250129206
|
| Publikation (Nr.) |
 EGU/EGU2016-9284.pdf |
|
|
|
|
|
| Zusammenfassung |
| The phenology of spring leaf unfolding is one of the key indicators of the climate change on
ecosystems, and influences regional and hemispheric-scale carbon balances and
plant-animal interactions. Changes in the phenology of spring leaf unfolding can also exert
biophysical feedbacks on climate by modifying the surface albedo and energy budget.
Recent studies have reported significant advances in spring phenology as a result of
warming in most northern hemisphere regions. Climate warming is projected to further
increase, but the future evolution of the phenology of spring leaf unfolding remains
uncertain — in view of the imperfect understanding of how the underlying mechanisms
respond to environmental stimuli. In addition, the relative contributions of each
environmental stimulus, which together define the apparent temperature sensitivity of the
phenology of spring leaf unfolding (advances in days per degree Celsius warming,
ST), may also change over time. An improved characterization of the variation in
phenological responses to spring temperature is thus valuable, provided that it addresses
temporal and spatial scales relevant for regional projections. Using long-term in situ
observations of leaf unfolding for seven dominant European tree species at 1,245
sites, we show here that the apparent response of leaf unfolding to climate warming
(ST, expressed in days advance per ˚ C) has significantly decreased from 1980
to 2013 in all monitored tree species. Averaged across all species and sites, ST
decreased by 40% from 4.0 ± 1.8 days ˚ C−1 during 1980-1994 to 2.3 ± 1.6 days ˚
C−1 during 1999-2013. The declining ST was also simulated by chilling-based
phenology models, albeit with a weaker decline (24%-30%) than observed in situ. The
reduction in ST is likely to be partly attributable to reduced chilling. Nonetheless, other
mechanisms may also play a role, such as ‘photoperiod limitation’ mechanisms
that may become ultimately limiting when leaf unfolding dates occur too early in
the season. Our results provide empirical evidence for a declining ST, but also
suggest that the predicted strong winter warming in the future may further reduce
ST and therefore result in a slowdown in the advance of tree spring phenology. |
|
|
|
|
|
|