Successful range-expanding plants experience less above-ground and below-ground enemy impact

Abstract

Many species are currently moving to higher latitudes and altitudes. However, little is known about the factors that influence the future performance of range-expanding species in their new habitats. Here we show that range-expanding plant species from a riverine area were better defended against shoot and root enemies than were related native plant species growing in the same area. We grew fifteen plant species with and without non-coevolved polyphagous locusts and cosmopolitan, polyphagous aphids. Contrary to our expectations, the locusts performed more poorly on the range-expanding plant species than on the congeneric native plant species, whereas the aphids showed no difference. The shoot herbivores reduced the biomass of the native plants more than they did that of the congeneric range expanders. Also, the range-expanding plants developed fewer pathogenic effects in their root-zone soil than did the related native species. Current predictions forecast biodiversity loss due to limitations in the ability of species to adjust to climate warming conditions in their range. Our results strongly suggest that the plants that shift ranges towards higher latitudes and altitudes may include potential invaders, as the successful range expanders may experience less control by above-ground or below-ground enemies than the natives.

In their native range, invasive plants are held in check by negative soil-feedbacks

“…Increased global trade and traffic, as well as species shifts as a result of global warming are major drivers of the introduction process. Results from recent studies suggest that plants that shift ranges towards higher latitudes and altitudes also include potential invaders (Engelkes et al 2008, Beaumont et al 2009, van Grunsven et al 2010.…”

“…The potential of native range-expanders and non-native invasive species to become a dominant component of newly invaded ecosystems might depend on biotic interactions (Joshi and Vrieling 2005, Suttle et al 2007, Engelkes et al 2008. Here, we define invasive species as species that have spread beyond their point of introduction in new ecosystems to become dominant (Valéry et al 2008).…”

Species-specific effects of polyploidisation and plant traits of Centaurea maculosa and Senecio inaequidens on rhizosphere microorganisms

“…Invasive genotypes have higher pyrrolizidine alkaloid concentrations than native ones (Cano et al 2009). The only existing study on the impact of S. inaequidens on the soil did not reveal any negative soil feedback (Engelkes et al 2008). However, no study has been done as yet to test for its impact on soil communities.…”

Range-expanding plant species and their belowground neighbours : digging into novel interactions

“…Nevertheless, within their new range, the few studies published thus far have shown that rangeexpanding plant species on average accumulate fewer pathogens and root-feeding nematodes, and are less negatively affected by soil communities than related native plant species (van Grunsven et al 2007;Engelkes et al 2008;Morriën, Duyts & Van der Putten 2012;Morriën & van der Putten 2013).…”

“…A particular study focus has been on root-feeding nematodes due to their prevalent role as agricultural pests. Similarly, a release from root-feeding nematodes has been suggested as an underlying driver of successful plant range-expansion (Engelkes et al 2008;Morriën, Duyts & Van der Putten 2012). …”