The objective of this PhD thesis project is to explore the hypothesis of a progressive decline of conifer competitiveness in mixed hardwood-coniferous forests with global warming. In order to develop a general conceptual approach, we will work with a couple of tree species emblematic of mixed forests in Europe and North America: the beech-fir mixture that is dominant in the European mid-elevation mountains and the more complex multi-species mixtures characteristic of the mixed forests of the northeastern United States.
The project will be structured into three work packages aiming to :
(1) assess the temporal growth trends of coniferous species compared to deciduous species from 1900 to 2022, focusing on the last decade, which contains 7 of the 10 warmest years ever measured;
(2) test the hypothesis of a coniferous vulnerability in the warm part of the climatic gradient and a growth stability in the cold part;
(3) explore the effect of the interspecific competition on the growth trends in mixed forests experiencing different competition levels (between 2 to 4 species in Europe and between 4 to 12 in North America).
The candidate must hold a Master’s degree in ecology, forest or environmental sciences and engineering, or a related field, with a good English level. Experience in conducting field work and handling big datasets, modelling, statistical analysis are preferred (particularly with R), but not exclusive for the successful candidate.