Characterization of the habitat- and season-independent increase in fungal biomass induced by the invasive giant goldenrod and its impact on the fungivorous nematode community

Abstract

Outside its native range, the invasive plant species giant goldenrod (Solidago gigantea) has been shown to increase belowground fungal biomass. This non-obvious effect is poorly characterized; we dont know whether it is plant developmental stage-dependent, which fractions of the fungal community are affected, and whether it is reflected in the next trophic level. To address the questions, fungal assemblages in soil samples collected from invaded and non-invaded plots in two soil types were compared. Whereas ergosterol as a marker for fungal biomass demonstrated a significant increase in fungal biomass, specific qPCR assays did not point at a quantitative shift. MiSeq-based characterization of the belowground effects of giant goldenrod revealed a local increase of mainly Cladosporiaceae and Glomeraceae. This asymmetric boost in the fungal community was reflected in a specific shift in the fungivorous nematode community. Our findings provide insight in the potential impact of invasive plants on local fungal communities.