Philippe Rozenberg is a senior researcher at INRAE Orléans, specializing in forest ecosystem adaptation to climate change. His work focuses on dendroecology, studying tree growth rings to understand trees’ historical responses to environmental changes. He also analyses phenotypic plasticity, examining how individuals adapt to environmental fluctuations, and uses population evolution through natural selection. Additionally, he explores science-society synergies, promoting climate adaptation solutions that are scientifically rigorous and respectful of forest users' diverse interests. His research advances both ecological understanding and practical solutions to environmental challenges.

Is the limited local adaptation of a mountain forest species an advantage in the face of climate change?

Findings from studies on the local adaptation of Alpine larch along an altitudinal gradient of over 1000 m (representing an 8°C difference in mean annual temperature) suggest low local adaptation at each altitude. These studies, combining genetic markers, reciprocal transplant experiments, and dendroecological analyses (annual ring growth), highlight key conclusions:

Gene flow: Extensive gene flow occurs across the gradient, facilitated by pollen dispersal. Seeds at any altitude are likely fertilized by trees from different altitudes, maintaining strong genetic connectivity between populations.

Environmental variation: Phenotypic differences in annual rings and phenology (ring formation, budburst) are mainly due to environmental variation, not genetic differences.

These findings indicate high evolutionary potential for adaptation at all altitudes. For example, at mid and high altitudes, seedlings may inherit drought-resistant traits from low-altitude trees, which are more exposed to water stress from global warming. Although low-altitude larches are more vulnerable to drought, experiments show that European larch can acclimate to warmer lowland climates. However, these larches are susceptible to pathogens like larch canker, which has not yet affected mountain populations, with one exception.