Data from: Allelopathy and its co-evolutionary implications between native and non-native neighbors of invasive Cynara cardunculus L.

Invasive plants apply new selection pressures on neighbor plant species by
different means including allelopathy. Recent evidence shows allelopathy
functions as remarkably influential mediator for invaders to be successful
in their invaded range. However, few studies have determined whether
native and non-native species co-occurring with invaders have evolved
tolerance to allelopathy. In this study, we conducted germination and
growth experiments to evaluate whether co-occurring native Juncus pallidus
and non-native Lolium rigidum species may evolve tolerance to the
allelochemicals induced by Cyanara cardunculus in Australian agricultural
fields. The test species were germinated and grown in pots filled with
collected invaded and uninvaded rhizosphere soil of C. cardunculus with
and without activated carbon (AC). Additionally, a separate experiment was
done to differentiate the direct effects of AC on the test species. The
soil properties showed invaded rhizosphere soils had higher total phenolic
and lower pH compared with un-invaded soils. We found significant
reduction of germination percentage and seedling growth in terms of
above-and below ground biomass, maximum plant height and root length of
native in the invaded rhizosphere soil of C. cardunculus, but little
effect on non-native grass species. Even soil manipulated with AC showed
no significant differences in the measured parameters of non-native except
aboveground biomass. Taken together, the results indicate allelochemicals
induced by C. cardunculus exert more suppressive effects on native than
non-native linking the co-evolved tolerance of those.