Selection of trees keeping pace with fast environmental changes, a science based approach for sustainable XXI century oak forests (KEEP PACE)

Fundação para a Ciência e a Tecnologia (FCT, Portugal; ALG-01-0145-FEDER-029263). PI: O.S. Paulo. Team member: F.X. Picó. 2018-2020.

The increment of the global climate change, since the last decades of the XX century is partially responsible for the decline affecting, the forest of Quercus suber (Cork Oak) and Quercus rotundifolia (Holm Oak), the two main trees of Montado type of habitat common in the western Mediterranean region, and in particular in Iberian peninsula. The ecological and socio-economic importance of these trees is well recognized but currently in Portugal alone, 20% of the cork oak forest is in decline. Biological species are responding to climate change by modifying their phenology and physiology, by adapt to the new local conditions and by changing their distribution. Trees and in particular oaks have a set of characteristics that made their response almost a paradox. Oaks combine high local differentiation for adaptive traits with extensive gene flow and harbour high levels of genetic diversity allowing them to adapt rapidly to local conditions. Local adaptation is driven by strong selection during early life stages and this seems not to be hampered by gene flow but on the contrary, enhance by it. Based on this rational, the main hypothesis to be tested in this project is that the change in adaptive traits can be already detected by genotyping young trees of natural regeneration developed after the beginning and increase of climatic/environmental changes, by comparing with local adult/old trees as well as by sample across steep climatic gradients. In both ways the genomic signature of local adaptation can be traced and unravelled the process, both Oaks species, are keeping pace with fast environmental changes. To achieve this aim the project use genomic resources already developed in other projects by the PI or other authors, approximately one hundred genomic regions/loci that can potentially be under selection, and sequence a large number of samples of the two species along environmental gradients and from two cohorts, using Illumina sequence. Additionally genotype-by-sequence, a method for obtaining genome wide markers, is used to increase the sample size in selected areas intensively affected by climate/environmental changes. The use of genomic information to detect local adaptation in a young cohort, allow the spatial and temporal projection of the association of the climatic/environmental factors with the local genetic variation and consequently modelled the future distribution of resilient types of genotypes. Based on genetic information, its environmental association, and on spatially explicit distribution model for these species, the project aims to develop a genetically-informed ecological niche model to improve climate/environmental change predictions. This result can be an important instrument for assisted gene flow or assisted migration, and consequently for the functional integrity of the Montado ecosystem, the future of the cork production and the associated socio-economic environment.