Epsilon Archive for Student Projects

Abstract

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.