Latitudinal variation in soil nematode communities under climate warming‐related range‐expanding and native plants

Abstract

Current climate change has led to latitudinal and altitudinal range expansions of numerous species. During such range expansions, plant species are expected to experience changes in interactions with other organisms, especially with belowground biota that have a limited dispersal capacity. Nematodes form a key component of the belowground food web as they include bacterivores, fungivores, omnivores and root herbivores. However, their community composition under climate change‐driven intracontinental range‐expanding plants has been studied almost exclusively under controlled conditions, whereas little is known about actual patterns in the field. Here, we use novel molecular sequencing techniques combined with morphological quantification in order to examine nematode communities in the rhizospheres of four range‐expanding and four congeneric native species along a 2,000 km latitudinal transect from South‐Eastern to North‐Western Europe. We tested the hypotheses that latitudinal shifts in nematode community composition are stronger in range‐expanding plant species than in congeneric natives and that in their new range, range‐expanding plant species accumulate fewest root‐feeding nematodes. Our results show latitudinal variation in nematode community composition of both range expanders and native plant species, while operational taxonomic unit richness remained the same across ranges. Therefore, range‐expanding plant species face different nematode communities at higher latitudes, but this is also the case for widespread native plant species. Only one of the four range‐expanding plant species showed a stronger shift in nematode community composition than its congeneric native and accumulated fewer root‐feeding nematodes in its new range. We conclude that variation in nematode community composition with increasing latitude occurs for both range‐expanding and native plant species and that some range‐expanding plant species may become released from root‐feeding nematodes in the new range.

Contrasting latitudinal clines of nematode diversity in Spartina alterniflora salt marshes between native and introduced ranges

“…One of the possible mechanisms for plant invasion is enemy release: invasive plants may be more productive in their new geographic range because they have escaped consumption by natural enemies (Keane & Crawley, 2002). Compared to the long evolutionary history of the native plant with the biota, there are known examples of rapid host shifts in response to introduced plants, including one example of an herbivore feeding on S. alterniflora in China (Zhang, Ju, Pan, Pan, & Wu, 2019); however, most evidence suggests that it takes a century or more for root‐associated nematodes (Lu et al, 2018; Wilschut et al, 2019) or an entire community to adapt to a novel host species (Bezemer et al, 2013; Brändle et al, 2008; Gruntman et al, 2017). In this study, we found the opposite result: in the native range of S. alterniflora , almost no nematodes were plant‐feeders, whereas up to 17 per cent were plant‐feeders in the introduced range in China in (Appendix : Figure ).…”

“…Compared with the well‐known geographic patterns in the diversity and abundance of aboveground organisms (Hillebrand, 2004; Mannion, Upchurch, Benson, & Goswami, 2014), the geographic patterns of belowground organisms are relatively understudied (but see Decaëns, 2010; Hendershot, Read, Henning, Sanders, & Classen, 2017; Maraun, Schatz, & Scheu, 2007). Because of the important interactions between aboveground and belowground processes, a better understanding of geographic patterns of belowground organisms is needed (Fierer, Strickland, Liptzin, Bradford, & Cleveland, 2009; Lu, He, Ding, & Siemann, 2018; van der Putten, 2012; Wilschut et al, 2019), especially in light of multiple global change factors (Bardgett & Wardle, 2010; Coyle et al, 2017) that may perturb both aboveground and belowground communities.…”

Community‐level interactions between plants and soil biota during range expansion

“…Together with these plant-associated organisms, other soil organisms, such as decomposers can also contribute to the net effects (the sum of positive and negative interactions) of plant-soil feedbacks during range expansions van der Putten, Bradford, Brinkman, van de Voorde, & Veen, 2016). Recent studies have shown that the community composition of soil organisms can change along the range expansion gradient (Ramirez et al, 2019;Wilschut et al, 2019). However, we have little information about how changes in the community composition of soil organisms associated to range expanding plants relate to possible differences in plant-soil feedback of these plants in their original and new range.…”

Plant population and soil origin effects on rhizosphere nematode community composition of a range-expanding plant species and a native congener

“…The online version of this article (https ://doi.org/10.1007/s0044 2-020-04749 -y) contains supplementary material, which is available to authorized users. compared to the original range (Ramirez et al 2019;Wilschut et al 2019a). Whether these soil communities from the original and new range are functionally different in terms of their impact on plant performance still remains poorly understood (Ramirez et al 2019;Van Nuland et al 2017;Wilschut et al 2019a).…”