Clementine Coston's thesis

Identification of functional traits related to hydraulic vulnerability involved in tree dieback during heatwave droughts and modeling of the probability of dieback

Clementine Coston

Team : Sureau

PhD student COSTON Clémentine

Thesis supervisors : ,  BALANDIER PhilippeCOCHARD Hervé

Dates : November 2025 - November 2028

 

Description

The mortality rate of metropolitan forest trees has doubled over the last decade, with advanced dieback now affecting stands on an unprecedented scale. The hot droughts accumulated since 2016 are the primary cause of this decline, sometimes reinforced by biotic attacks. As a result, trees are subjected to a double constraint: extreme heat spikes at times when water is no longer available. The role of silviculture and in particular the thinning regime is then highlighted: while thinning reduces competition between trees, it opens the stand and alters the microclimate. The air within the stand is then drier and warmer.
The thesis subject aims to better characterize and understand the functioning of trees in relation to the management of the forest microclimate by silviculture. Based on the measurement of functional traits of resistance to heatwave and drought, the probability of dieback linked to the thinning regime will be modeled to provide new management criteria to forest stakeholders.