|Title||Below-ground effects of related exotic and native plant species on primary decomposers as well as their main grazers; bacterivorous and fungivorous nematodes|
|Author(s)||Harkes, P.; Helder, J.|
|Event||32nd Symposium European Society of Nematologist, Braga, 2016-08-28/2016-09-01|
Laboratory of Nematology
|Publication type||Abstract in scientific journal or proceedings|
|Abstract||Introduction of non-indigenous species is one of the major drivers of changes in biological communities. Above-ground effects of exotic plant species on the vegetation composition are generally spoken easily scorable and relatively well documented. Although its relevance in terms of ecological functioning is nondisputed, far less attention has been paid to below-ground effects of invasive plant species on the rhizosphere food web. Here, we compared the rhizosphere community of an exotic plant species, narrow-leaved ragwort (Senecio inaequidens), with the
community surrounding the roots of a native relative, tansy ragwort (Jacobeae vulgaris). In this study, the primary decomposer community (bacteria and fungi), as well as the nematode grazing on these groups (bacterivorous and fungivorous nematodes), are taken into consideration. Rhizosphere samples were collected from three semi-natural grassland sites with high plant diversity in which both ragwort species were growing in close proximity. In total 96 rhizosphere samples were collected from two phenological stages of S. inaequidens and J. vulgaris. A set of newly developed quantitative PCR (qPCR) assays was used for a quantitative analysis of bacterial and fungal communities at phylum-level. In addition, changes among bacterivorous and fungivorous nematode taxa were monitored. To our surprise the effect of plant developmental stage was shown to be stronger than the native versus exotic plant species effect. This was not only true for the bacterial and fungal community, but also for the 15 most prominent nematode taxa present in these habitats. Correlation between changes in
primary decomposer community and the nematode community grazing on it will be highlighted.