Data from: The differential impact of a native and a non-native ragwort species (Senecioneae) on the first and second trophic level of the rhizosphere food web

Whereas the impact of exotic plant species on above-ground biota is
relatively well-documented, far less is known about the effects of
non-indigenous plants on the first and second trophic level of the
rhizosphere food web. Here, rhizosphere communities of the invasive
narrow-leaved ragwort Senecio inaequidens and the native tansy ragwort
Jacobaea vulgaris, co-occurring in three semi-natural habitats are
compared. For both species, two life stages were taken into consideration.
Quantitative PCR assays for the analyses of bacterial and fungal
communities at a high taxonomic level were optimized, and it was
investigated whether changes in the primary decomposer community were
translated in alterations in bacterivorous and fungivorous nematode
communities. In contrast to J. vulgaris, small but significant reductions
were observed for Actinobacteria and Bacteroidetes (both p < 0.05)
in case of the invasive S. inaequidens. More pronounced changes were
detected for the overall nematode community density, and, more
specifically, for the bacterivorous genus Anaplectus and the family
Monhysteridae (both p < 0.05), as well as the necromenic
Pristionchus (p < 0.001). At high taxonomic level, no differences
were observed in fungal rhizosphere communities between native and
non-native ragwort species. The impact of plant developmental stages on
rhizosphere biota was prominent. The overall bacterial and fungal
biomasses, as well as a remarkably consistent set of constituents
(Actinobacteria, α- and β-Proteobacteria and Bacteroidetes) were
negatively affected by plant stage for both ragwort species. Although
later developmental stages of plants generally coincided with lower levels
for individual nematode taxa, densities of the fungivorous genera
Diphtherophora and Tylolaimophorus remain unaltered. Hence, even at a high
taxonomic level, differential effects of native and non-native ragwort
could be pinpointed. However, plant developmental stage has a more
prominent impact and this impact was similar in nature for both native and
non-native ragwort species.