Belowground Plant-Herbivore Interactions Vary among Climate-Driven Range-Expanding Plant Species with Different Degrees of Novel Chemistry.

Rutger A Wilschut,Wim H Van Der Putten,Paolina Garbeva,Julio C P Silva

doi:10.3389/fpls.2017.01861

Rutger A Wilschut, Wim H Van Der Putten + Show 2 more

Open Access

https://doi.org/10.3389/fpls.2017.01861

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Abstract

An increasing number of studies report plant range expansions to higher latitudes and altitudes in response to global warming. However, consequences for interactions with other species in the novel ranges are poorly understood. Here, we examine how range-expanding plant species interact with root-feeding nematodes from the new range. Root-feeding nematodes are ubiquitous belowground herbivores that may impact the structure and composition of natural vegetation. Because of their ecological novelty, we hypothesized that range-expanding plant species will be less suitable hosts for root-feeding nematodes than native congeneric plant species. In greenhouse and lab trials we compared nematode preference and performance of two root-feeding nematode species between range-expanding plant species and their congeneric natives. In order to understand differences in nematode preferences, we compared root volatile profiles of all range-expanders and congeneric natives. Nematode preferences and performances differed substantially among the pairs of range-expanders and natives. The range-expander that had the most unique volatile profile compared to its related native was unattractive and a poor host for nematodes. Other range-expanding plant species that differed less in root chemistry from native congeners, also differed less in nematode attraction and performance. We conclude that the three climate-driven range-expanding plant species studied varied considerably in their chemical novelty compared to their congeneric natives, and therefore affected native root-feeding nematodes in species-specific ways. Our data suggest that through variation in chemical novelty, range-expanding plant species may vary in their impacts on belowground herbivores in the new range.

Highlights

One of the most evident ecological consequences of current climate change is the latitudinal and altitudinal range expansion of many plant and animal species (Walther et al, 2002; Parmesan, 2006; Le Roux and Mcgeoch, 2008)
Range-expanding plant species that were examined in the experiments were Centaurea stoebe L., Geranium pyrenaicum Burm. f., and Rorippa austriaca Crantz and their congeneric native species were C. jacea L., G. molle L., and R. sylvestris (L.) Besser
Seeds of C. jacea were collected from mother plants that were grown in an outside experiment at NIOO-KNAW (Wageningen, The Netherlands) from seeds collected in a natural population

Summary

Introduction

One of the most evident ecological consequences of current climate change is the latitudinal and altitudinal range expansion of many plant and animal species (Walther et al, 2002; Parmesan, 2006; Le Roux and Mcgeoch, 2008). As not all species expand their range at similar rates (Berg et al, 2010), coevolved interactions between plants, aboveground and belowground organisms are likely. Novel Root Chemistry of Climate-Driven Range-Expanders to become disrupted, whereas novel interactions can be developed in the new range (Lavergne et al, 2010; Van Der Putten, 2012). Range-expanding plant species might benefit from these new biotic conditions when they do not encounter coevolved natural enemies in the expanded range (De Frenne et al, 2014; Dostálek et al, 2015). The present study was initiated in order to examine how root herbivores in the new range respond to range-expanding plant species

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