Trait variation in Lodgepole Pine : do populations differ in traits depending on if they are invasive or in their home range?

As a result of the global world we today live in, species are transported outside of their native range to new areas. Some of these species becomes invasive, which can cause a variety of negative effects. Traits are often thought to play an important role in invasion success. The purpose with this thesis was therefore to test if and how traits of the invasion species Pinus contorta varied depending on the subspecies, and where it is growing (i.e. native or introduced range). Samples had prior to this thesis been gathered from 3 subspecies of P. contorta in its native range (USA) and from an unspecified subspecies in plantations and invasion fronts in an introduced range (Patagonia). Traits of sampled needles, seeds and cones were then used as a basis for multivariate and univariate analyses to detect significant differences between the sampled categories. Significant trait differences were found between the three native subspecies: latifolia, murrayana and contorta. The Patagonian P. contorta was found to be the most similar to the native subspecies murrayana. Also, the Patagonian P. contorta had traits that differed significantly from all of the native subspecies. Overall I found no statistical evidence of a lower trait variation in the introduced P. contorta compared to the native. I further found some trait differences between the Patagonian P. contorta trees in the plantations and at the invasion front. As a whole my results indicate that invasive species can differ in traits when comparing the species in the native and introduced range, thus providing an example of an invasive species displaying a change in traits compared to their native range. The results can also be used to support several of the existing hypotheses regarding invasion success.