Le mardi 8 septembre, Alistair Jump, professeur à l’Université de Stirling et spécialiste de la réponse des plantes aux changements climatiques a présenté un séminaire intitulé:
“Differential impacts of chronic and acute drought across the geographic range of tree species”
Centre INRA de Nancy-Lorraine
mardi, 8 septembre
Résumé :
Ongoing changes in temperature and precipitation regimes are driving shifts in species distributions and community composition. In forest trees, the most conspicuous changes are occurring at the range edges, where expansion to higher altitudes and latitudes is frequently observed. Range retractions at low altitudes and latitudes are less commonly reported, partly since expansion occurs through rapid establishment, whereas contraction is associated with the typically slower death of existing adults. However repeated reproductive failure despite continued adult growth can predispose populations to rapid future decline, while in a community context, differential impacts of climate change on co-occurring species can lead to sudden and unpredictable shifts in competitive dominance between species. I will discuss recent experimental and observational work on temperate tree species in which we have assessed impacts of both chronic and acute changes in climate across different populations and genotypes. Mechanisms including altered phenology, biomass allocation, and carbon economy lead to differences in fitness at the population level. However, even within populations, individual variation in drought resistance can translate into significant community-level impacts. Understanding the scale and pattern of variation in drought resistance within species is key to predicting their presence and abundance over future decades.
En savoir plus ..
Visitez le profile de Alistair Jump, professeur à l’Université de Stirling
Lire le résumé de son article publié en 2013 dans le journal Functional Ecology : Extreme drought alters competitive dominance within and between tree species in a mixed forest stand
