The TransX project: A latitudinal network of provenance trials across eastern North America to test the climatic vulnerability of northeastern tree species and their potential for assisted migration

Adaptive silviculture hinges on our capacity to predict future changes in tree species demography (e.g. growth, mortality) in response to climate change. Experimental tree translocation studies across climate gradients can help anticipate such changes. The TransX experiment is a network of provenance trials, ranging from North Carolina (US) to Quebec (CA), where populations of ten boreal and temperate tree species, and genetically improved genotypes of four commercially important tree species have been planted simultaneously and will be monitored for their response to gradients of 14.5°C in mean annual temperature and 600 mm in precipitation. The objectives of this experiment are to: 1) quantify the effect of climate on trait variation and plasticity across selected tree populations and species, and 2) assess how such trait variation relates to growth and survival. Here we outline the design of the experiment, and describe the research efforts to monitor annual survival, health, growth, leaf morphology and physiology, and track leaf phenology using time-lapse cameras. By exposing major tree species to a wide range of climate and site conditions, the TransX project will fill significant knowledge gaps on forest ecosystem responses to climate change and inform adaptive management strategies, such as forest assisted migration.