An invasive plant rapidly increased the similarity of soil fungal pathogen communities
Lu, Xinmin (2020), An invasive plant rapidly increased the similarity of soil fungal pathogen communities, Dryad, Dataset, https://doi.org/10.5061/dryad.gtht76hjv
Background and Aims: Plant invasions can change soil microbial communities and affect subsequent invasions directly or indirectly via foliar herbivory. It has been proposed that invaders promote uniform biotic communities that displace diverse, spatially variable communities (“Biotic Homogenization Hypothesis”) but this has not been experimentally tested for soil microbial communities, so the underlying mechanisms and dynamics are unclear. Here, we compared density-dependent impacts of the invasive plant Alternanthera philoxeroides and its native congener A.sessilis on soil fungal communities, and their feedback effects on plants and a foliar beetle.
Methods: We conducted a plant-soil feedback (PSF) experiment and a lab bioassay to examine PSFs associated with the native and invasive plants and a beetle feeding on them. We also characterized the soil fungal community using high-throughput sequencing.
Key Results: We found locally differentiated soil fungal pathogen assemblages associated with high densities of the native plant Alternanthera sessilis but little variation in those associated with the invasive congener A. philoxeroides regardless of plant density. In contrast, AM fungal assemblages associated with high densities of the invasive plant were more variable. Soil biota decreased plant shoot mass but their effect was weak for the invasive plant growing in native plant conditioned soils. PSFs increased the larval biomass of a beetle reared on leaves of the native plant only. Moreover, PSFs on plant shoot, root and beetle mass were predicted by different pathogen taxa in a plant species-specific manner.
Conclusion: Our results suggest that plant invasions can rapidly increase the similarity of soil pathogen assemblages even at low plant densities leading to taxonomically and functionally homogeneous soil communities that may limit negative soil effects on invasive plants.