Plant movements and climate warming: intraspecific variation in growth responses to nonlocal soils

Abstract

SummaryMost range shift predictions focus on the dispersal phase of the colonization process. Because moving populations experience increasingly dissimilar nonclimatic environmental conditions as they track climate warming, it is also critical to test how individuals originating from contrasting thermal environments can establish in nonlocal sites.We assess the intraspecific variation in growth responses to nonlocal soils by planting a widespread grass of deciduous forests (Milium effusum) into an experimental common garden using combinations of seeds and soil sampled in 22 sites across its distributional range, and reflecting movement scenarios of up to 1600 km. Furthermore, to determine temperature and forest-structural effects, the plants and soils were experimentally warmed and shaded.We found significantly positive effects of the difference between the temperature of the sites of seed and soil collection on growth and seedling emergence rates. Migrant plants might thus encounter increasingly favourable soil conditions while tracking the isotherms towards currently 'colder' soils. These effects persisted under experimental warming. Rising temperatures and light availability generally enhanced plant performance.Our results suggest that abiotic and biotic soil characteristics can shape climate changedriven plant movements by affecting growth of nonlocal migrants, a mechanism which should be integrated into predictions of future range shifts.

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

“…Climate warming-induced range-expanding plant species can experience weaker negative impact in soil from the new than from the original range (van Grunsven et al 2010;De Frenne et al 2014;Dostálek et al 2015;Van Nuland, Bailey & Schweitzer 2017). This may be caused by the loss of belowground natural enemies, such as root-feeding nematodes and soil-borne pathogens, as a result of plants having higher dispersal capacities than soil biota (Berg et al 2010;Morriën et al 2010).…”

“…Although range-expanding plant species are thought to benefit when released from their specialized soil-borne enemies after latitudinal range-expansion (van Grunsven et al 2010;De Frenne et al 2014), plants will still be exposed to natural enemies in the new range, including widespread generalist enemies. Both Meloidogyne hapla and Helicotylenchus pseudorobustus are widespread throughout Europe (Bongers 1988), which does not exclude a co-evolutionary history with all four plant species.…”

“…Such a disruption of plant-enemy interactions due to intra-continental range expansion may not be as strong when compared to intercontinental introductions, as some natural enemies of range-expanders may have wider distributions and will therefore already be present at higher latitudes (Menendez et al 2008). Yet, an increasing number of studies show that some range-expanding plant species are less affected by soil communities in their new range compared to their original range, suggesting a degree of enemy release (van Grunsven et al 2010;De Frenne et al 2014;Dostálek et al 2015;Van Nuland, Bailey & Schweitzer 2017). However, comparisons between the compositions of soil communities from the original and new range of rangeexpanding plant species so far have rarely been made (Van Nuland, Bailey & Schweitzer 2017).…”

“…Some recent studies have shown that climate warming-induced range-expanding plant species or populations can be less strongly affected by belowground enemies in their new range than in their old range (van Grunsven et al 2010;De Frenne et al 2014). Moreover, these range-expanders may experience less negative effects of soil organisms in their new range than congeneric natives (van Grunsven et al 2007;Engelkes et al 2008).…”

“…Through plant range-expansions, interactions between plants and specific rhizosphere communities can be disrupted with functional consequences for plant performance in the new range (Morriën et al 2010;van der Putten 2012). Indeed, several rangeexpanding plant species seem to be less negatively affected by soil communities in their new than in their original range, suggesting that range expansion enables release from natural enemies from the original range (van Grunsven et al 2010;De Frenne et al 2014;Dostálek et al 2015;Van Nuland, Bailey & Schweitzer 2017).…”