Geographic variation in trees has been investigated since the mid-18th century. Similar patterns of clinal variation have been observed along latitudinal and elevational gradients in common garden experiments for many temperate and boreal species. These studies convinced forest managers that a ‘local is best’ seed source policy was usually safest for reforestation.
Aitken SA, Bemmels JB. 2016. Time to get moving: assisted gene flow of forest trees. Evolutionary applications 9: 271-290. Full text available at:http://onlinelibrary.wiley.com/doi/10.1111/eva.12293/full
