Do traits within species vary more locally or regionally?
Intraspecific trait variation (ITV) can be surprisingly high for some plant species, but it is not clear why. Understanding how ITV changes with spatial scale can shed light on competing explanations. In six common understory plants, sampled across Canada, ITV of both leaves and roots was greater at local scales – including contrasts of disturbed and undisturbed habitat – than between bioclimatic regions. This CIEE working group used an extensive data set of 818 populations collected by the Co-Vitas project.