ExpandTree is a 3 years (2014-2017) research project supported by the French and the Portuguese funding agencies, the ANR (Agence Nationale de la Recherche) and FCT (Fundação para a Ciencia e a Tecnologia) with an overall budget of 158.719,2 €.
Forests have been managed, fragmented or disturbed for centuries. Satellite images show a net increase of forest cover due to recent socio-economical changes across Europe and North America. As a result, isolated remnant forest have expanded to coalesce to form larger patches or continuos forest. Yet, other drivers of global change, such as climate-driven changes or defaunation, might hamper natural regeneration and population expansion. The initial establishment of colonising tree populations goes along with a diverse evolutionary processes (e.g. founder effects, genetic drift, local adaptation) that are expected to influence population's chances to persist.
Our study species are two Mediterranean forest species, Phoenicean juniper (Juniperus phoenicea subsp. turbinata) and the Atlas cedar (Cedrus atlantica) that inhabit coastal dunes and high mountains, respectively. We are applying an integrative approach by combining aerial pictures, field data, spatial-explicit evolutionary models, and genetic and genomic resources to: 1) track long-term demographic expansion patterns and identify the main ecological drivers enhancing or hampering forest regeneration; 2) understand how demographic and evolutionary processes interact at the colonization front; and 3) to identify sings of local selection in the colonisation front in response to climate-driven changes. Interestingly, the Phoenicean juniper is actively dispersed by vertebrates whereas the Atlas cedar is wind-dispersed. This is key difference that will allow us to evaluate the importance of seed dispersal ability in driving expansion patterns and setting the evolutionary dynamics in the colonisation front.
Forests have been managed, fragmented or disturbed for centuries. Satellite images show a net increase of forest cover due to recent socio-economical changes across Europe and North America. As a result, isolated remnant forest have expanded to coalesce to form larger patches or continuos forest. Yet, other drivers of global change, such as climate-driven changes or defaunation, might hamper natural regeneration and population expansion. The initial establishment of colonising tree populations goes along with a diverse evolutionary processes (e.g. founder effects, genetic drift, local adaptation) that are expected to influence population's chances to persist.
Our study species are two Mediterranean forest species, Phoenicean juniper (Juniperus phoenicea subsp. turbinata) and the Atlas cedar (Cedrus atlantica) that inhabit coastal dunes and high mountains, respectively. We are applying an integrative approach by combining aerial pictures, field data, spatial-explicit evolutionary models, and genetic and genomic resources to: 1) track long-term demographic expansion patterns and identify the main ecological drivers enhancing or hampering forest regeneration; 2) understand how demographic and evolutionary processes interact at the colonization front; and 3) to identify sings of local selection in the colonisation front in response to climate-driven changes. Interestingly, the Phoenicean juniper is actively dispersed by vertebrates whereas the Atlas cedar is wind-dispersed. This is key difference that will allow us to evaluate the importance of seed dispersal ability in driving expansion patterns and setting the evolutionary dynamics in the colonisation front.