Translocated southern seedlings perform as well as local provenances: insights from an ecophysiological monitoring under varying cutting modalities

Forest assisted migration, the human-mediated movement of tree populations or species, is an adaptive silvicultural tool that could help forest transition to future climate while maintaining their productivity and ecosystem services. However, we need additional knowledge about the physiology of translocated seedlings to select the most appropriate species, provenances (i.e., seed sources) and silvicultural treatments surrounding this adaptive strategy. We used the first experimental site of the DREAM Network to assess early ecophysiology of local and translocated seedlings of eight species ( Prunus serotina , Quercus rubra , Acer saccharum , Picea glauca , Picea rubens , Pinus strobus , Pinus resinosa and Thuja occidentalis ). Seedlings were planted in a mixed plantation design in patch clearcut and in regular shelterwood system. For each species, seedlings were produced from three geographical provenances representing current climate (2018), mid-century and end-century climates (predicted for 2050 and 2080), based on climate analogues. Shelterwood partial cover proved useful during the establishment (e.g., to protect seedlings from late frost) with limited impacts on physiological performance. When planted in patch clearcut, Prunus serotina , Quercus rubra and Acer saccharum from mid-century and end-century climate analogues experienced lower water stress, suggesting a better drought tolerance than those from local provenances. Overall, insights from this ecophysiological monitoring indicated that translocated southern seedlings perform as well as or better than local provenances, suggesting that they can acclimate to their new destination site.