TY - JOUR
T1 - What drives phenological synchrony? Warm springs advance and desynchronize flowering in oaks
AU - Bogdziewicz, M.
AU - Szymkowiak, J.
AU - Bonal, R.
AU - Hacket-Pain, A.
AU - Espelta, J. M.
AU - Pesendorfer, M.
AU - Grewling, L.
AU - Kasprzyk, I.
AU - Belmonte, J.
AU - Kluska, K.
AU - De Linares, C.
AU - Penuelas, J.
AU - Fernandez-Martinez, M.
N1 - Funding Information:
We thank two Anonymous Reviewers for their comments on the previous version of this manuscript. MB was supported by the (Polish) National Science Centre grant numbers 2018/28/U/NZ8/00003 (Uwertura) and 2017/24/C/NZ8/00151 (Sonatina). MFM is a postdoctoral fellow of the Research Foundation-Flanders (FWO). MBP is supported by the Austrian Science Foundation (FWF) project number P30381 . This work contributes to the ICTA-UAB ‘Unit of Excellence’ (MinECo, MDM2015–0552). JP acknowledges the financial support from the European Research Council Synergy grant ERC-SyG-2013–610028 IMBALANCE-P ).
Publisher Copyright:
© 2020 Elsevier B.V.
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020/11/15
Y1 - 2020/11/15
N2 - Annually variable and synchronous seed production, or masting, is often correlated with environmental factors and in oaks involves differential pollination success that depends on phenological synchrony in flowering. The synchronization of phenology of flowering was thought to be driven by temperature during flowering (microclimatic hypothesis). We tested an alternative, whereby phenological synchronization is driven by the timing of the onset of flowering (photoperiod-sensitivity hypothesis). This hypothesis assumes that flowering synchrony is driven by interaction between daylength and temperature, and individual variation in sensitivity to daylength as a phenological cue. We used long-term (23–26 years) records of airborne pollen in Quercus robur, Q. petraea, Q. ilex, and Q. humilis. Late pollen seasons were short, as predicted by photoperiod-sensitivity hypothesis. The onset of pollen seasons was delayed as preseason temperatures cooled over the last three decades at our Mediterranean sites, which was paralleled by shortening in pollen seasons, providing additional support for the photoperiod-sensitivity hypothesis. Global warming under the microclimatic hypothesis is predicted to lead to less frequent reproductive failures and thus decreased variability and synchrony of mast seeding. In contrast, warming under the photoperiod-sensitivity hypothesis should advance the onset of and desynchronize flowering, a pattern supported by our data. This pattern suggests that global warming will lead to more frequent vetoes and more stochastic and variable patterns of oak reproduction.
AB - Annually variable and synchronous seed production, or masting, is often correlated with environmental factors and in oaks involves differential pollination success that depends on phenological synchrony in flowering. The synchronization of phenology of flowering was thought to be driven by temperature during flowering (microclimatic hypothesis). We tested an alternative, whereby phenological synchronization is driven by the timing of the onset of flowering (photoperiod-sensitivity hypothesis). This hypothesis assumes that flowering synchrony is driven by interaction between daylength and temperature, and individual variation in sensitivity to daylength as a phenological cue. We used long-term (23–26 years) records of airborne pollen in Quercus robur, Q. petraea, Q. ilex, and Q. humilis. Late pollen seasons were short, as predicted by photoperiod-sensitivity hypothesis. The onset of pollen seasons was delayed as preseason temperatures cooled over the last three decades at our Mediterranean sites, which was paralleled by shortening in pollen seasons, providing additional support for the photoperiod-sensitivity hypothesis. Global warming under the microclimatic hypothesis is predicted to lead to less frequent reproductive failures and thus decreased variability and synchrony of mast seeding. In contrast, warming under the photoperiod-sensitivity hypothesis should advance the onset of and desynchronize flowering, a pattern supported by our data. This pattern suggests that global warming will lead to more frequent vetoes and more stochastic and variable patterns of oak reproduction.
KW - Flowering onset
KW - Flowering synchrony
KW - Global warming
KW - Microclimatic variation
KW - Phenology
KW - Photoperiod sensitivity
KW - Pollen
UR - http://www.scopus.com/inward/record.url?scp=85089586773&partnerID=8YFLogxK
U2 - 10.1016/j.agrformet.2020.108140
DO - 10.1016/j.agrformet.2020.108140
M3 - Artículo
AN - SCOPUS:85089586773
VL - 294
JO - Agricultural and Forest Meteorology
JF - Agricultural and Forest Meteorology
SN - 0168-1923
M1 - 108140
ER -