Intraspecific plant–soil feedback and intraspecific overyielding in Arabidopsis thaliana

Abstract

Understanding the mechanisms of community coexistence and ecosystem functioning may help to counteract the current biodiversity loss and its potentially harmful consequences. In recent years, plant–soil feedback that can, for example, be caused by below-ground microorganisms has been suggested to play a role in maintaining plant coexistence and to be a potential driver of the positive relationship between plant diversity and ecosystem functioning. Most of the studies addressing these topics have focused on the species level. However, in addition to interspecific interactions, intraspecific interactions might be important for the structure of natural communities. Here, we examine intraspecific coexistence and intraspecific diversity effects using 10 natural accessions of the model species Arabidopsis thaliana (L.) Heynh. We assessed morphological intraspecific diversity by measuring several above- and below-ground traits. We performed a plant–soil feedback experiment that was based on these trait differences between the accessions in order to determine whether A. thaliana experiences feedback at intraspecific level as a result of trait differences. We also experimentally tested the diversity–productivity relationship at intraspecific level. We found strong differences in above- and below-ground traits between the A. thaliana accessions. Overall, plant–soil feedback occurred at intraspecific level. However, accessions differed in the direction and strength of this feedback: Some accessions grew better on their own soils, some on soils from other accessions. Furthermore, we found positive diversity effects within A. thaliana: Accession mixtures produced a higher total above-ground biomass than accession monocultures. Differences between accessions in their feedback response could not be explained by morphological traits. Therefore, we suggest that they might have been caused by accession-specific accumulated soil communities, by root exudates, or by accession-specific resource use based on genetic differences that are not expressed in morphological traits. Synthesis. Our results provide some of the first evidence for intraspecific plant–soil feedback and intraspecific overyielding. These findings may have wider implications for the maintenance of variation within species and the importance of this variation for ecosystem functioning. Our results highlight the need for an increased focus on intraspecific processes in plant diversity research to fully understand the mechanisms of coexistence and ecosystem functioning.

The strength of negative plant–soil feedback increases from the intraspecific to the interspecific and the functional group level

“…However, the individual accessions and species differed in the direction and strength of the feedback. With regard to intraspecific plant–soil feedback, we had formerly shown that A. thaliana accessions differ in the strength and direction of experienced feedback (Bukowski & Petermann, 2014). The same accessions in our experiment showed different feedback strengths and directions compared to this earlier study.…”

“…However, most soil feedback studies refer to the interspecific level only, comparing growth of plants on own soil with growth on soil from other species. Recently, it has been shown that plant–soil feedback may operate at the intraspecific level, that is, that there are differences in plant growth on own soil compared with growth on soil from different accessions or genotypes within the same species (Bukowski & Petermann, 2014; Liu, Etienne, Liang, Wang, & Yu, 2015). Despite indications that certain pathogens may have similar effects on closely related species (Gilbert, Briggs, & Magarey, 2015; Parker et al., 2015), it is still unclear whether there is a difference in feedback strength between the intraspecific and the interspecific levels (van der Putten et al., 2013).…”

Tree genetics strongly affect forest productivity, but intraspecific diversity–productivity relationships do not

“…; Hughes et al . ; Bukowski & Petermann ), there may be significant variation in the magnitude of such effects. Our study was unique in that we both sampled from tremendous phenotypic variation in a tree single species (by sampling genetic stock from throughout the range of the species), and out planted all genotypes in a single environment.…”

Intraspecific variation in indirect plant–soil feedbacks influences a wetland plant invasion

“…, Bowen et al. ), yet experiments examining intraspecific variation in PSFs remain rare (but see Bukowski and Petermann , Maron et al. , Wagg et al.…”