+ 33 4 34 35 98 94 ecotron@cnrs.fr
CIRCAFLUX
2013

Goals

To test the impact of the circadian cycle of two types of plants (Beans and Cotton) on the regulation of their stomatal conductance and on their gas exchanges.

number of rooms used

  •  12

Project duration

  •  3 months

A new experiment on circadian rhythms

Researchers

Arthur Gessler ; Jacques Roy ; Zachary Kayler ; Juan Pedro Ferrio ; Josu Alday ; Michael Bahn ; Jorge del Castillo ; Víctor Resco de Dios ; Sébastien Devidal ; Sonia García-Muñoz ; Damien Landais ; Paula Martín-Gómez ; Alexandru Milcu ; Clément Piel ; Karin Pirhofer-Walzl ; Serajis Salekin ; David Tissue ; Mark Tjoelker ; Jordi Voltas ; William RL Anderegg

 

Informations

University of Lleida – University of Utah – Hawkesbury Institute for the Environment Western Sydney – Department of Ecology, University of Innsbruck – Ecotron – CEFE – Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research

 

Publications

  • Circadian regulation of night-time dark respiration and light-enhanced dark respiration in plant leaves and canopies. Journal : Environmental and Experimental Botany Référence : LIRE…
  • Circadian rhythms regulate the environmental responses of net CO2 exchange in bean and cotton canopies. Journal : Agricultural and Forest Meteorology Référence : LIRE…
  • Circadian rhythms have significant effects on leaf-to-canopy scale gas exchange under field conditions. Journal : GigaScience Référence : LIRE…
Context
This study builds on previous efforts (Resco de Dios et al, Ecology Letters, (2009) 12: 583-592; Resco de Dios et al, Global Change Biology, (2012) 18, 1956-1970; Resco de Dios et al, New Phytologist, in press), to understand the role of the circadian clock in ecosystem processes. This earlier work provided circumstantial evidence of circadian regulation of the net ecosystem exchange of CO2 and water, as well as BVOC emissions, by combining filtering and modelling techniques to minimize environmental variation in data sets and short (12-hour) overnight manipulations. However, we still lack a direct and unequivocal test of circadian regulation of gas exchange beyond the leaf level and in the field. The only direct test of the circadian regulation of ENE, ET and BVOC emissions at the ecosystem level is continuous monitoring for a period of ~24/48 hours with constant levels of light, temperature and other environmental factors (“continuous environment” below).
Treatments
2 crops, cotton and beans, studied successively; 2 experimental phases: no water limitation, drought. Each phase lasts two weeks for one crop. The choice of the first crop will depend on the development of the awnings. When the second crop begins to be studied, the first crop goes into drought. Then it is 4 weeks of study under good water conditions and then 4 weeks under drought conditions

Each phase has 2 sub-phases : a first one for the study of the circadian rhythm in constant light and a second one for the study of the circadian rhythm in constant darkness. The study of the circadian rhythm consists in the comparison of the physiology under varying daytime conditions and under constant conditions. The variable conditions are controlled (made with artificial lamps to have similar conditions regardless of the outdoor weather and to have a maximum light level equal to the constant light level that will be imposed by the lamps).

A phase lasts two weeks with the following sequence of activities each day.