CR 46:147-157 (2011)  -  doi:10.3354/cr00980

Modelling the timing of Betula pubescens budburst. I. Temperature and photoperiod: a conceptual model

Amelia Caffarra1,*, Alison Donnelly2, Isabelle Chuine3, Mike B. Jones2

1Research and Innovation Centre, Agriculture Area, Fondazione Edmund Mach, San Michele all’Adige, 38100 Trento, Italy
2Department of Botany, School of Natural Sciences, Trinity College Dublin, Dublin 2, Ireland
3CEFE-CNRS, 1919 route de Mende, 34293 Montpellier, France

ABSTRACT: The main factors triggering and releasing bud dormancy are photoperiod and temperature. Their individual and combined effects are complex and change along a transition from a dormant to a non-dormant state. Despite the number of studies reporting the effects of temperature and photoperiod on dormancy release and budburst, information on the parameters defining these relationships is scarce. The aim of the present study was to investigate the effects and interaction of temperature and photoperiod on the rates of dormancy induction and release in Betula pubescens (Ehrh.) in order to develop a conceptual model of budburst for this species. We performed a series of controlled environment experiments in which temperature and photoperiod were varied during different phases of dormancy in B. pubescens clones. Endodormancy was induced by short days and low temperatures, and released by exposure to a minimal period of chilling temperatures. Photoperiod during exposure to chilling temperatures did not affect budburst. Longer exposure to chilling increased growth capability (growth rate at a given forcing temperature) and decreased the time to budburst. During the forcing phase, budburst was promoted by photoperiods above a critical threshold, which was not constant, but decreased upon longer chilling exposures. These relationships between photoperiod and temperature have, as yet, not been integrated into the commonly used process-based phenological models. We suggest models should account for these relationships to increase the accuracy of their predictions under future climate conditions.

KEY WORDS: Betula pubescens · Controlled environment experiments · Phenology · Photoperiod · Temperature · Dormancy · Budburst

Full text in pdf format 
Cite this article as: Caffarra A, Donnelly A, Chuine I, Jones MB (2011) Modelling the timing of Betula pubescens budburst. I. Temperature and photoperiod: a conceptual model. Clim Res 46:147-157

Export citation: Endnote - Reference Manager
Mail this link - Contents Mailing Lists - RSS
- -