Global warming, elevated atmospheric CO 2 concentrations and increased likeliness
of extreme drought and wildfires in many regions will likely favour C4 grass species.
To support future management actions, we explored the effect of the encroachment of
an invasive perennial C4 grass, Sporobolus cryptandrus on the composition of soil
seed banks in dry sand grasslands in Central Europe. In five mass‐locality sites of
the species we assessed the composition and vertical segmentation of the soil seed
bank in 12 1‐m 2 plots along an increasing cover of the invasive species. We found
that the seed bank diversity and density decreased with increasing sampling depth;
the decrease in density was affected by the increasing S. cryptandrus cover. Neither
the diversity nor the seed bank density of other species were affected by increasing
S. cryptandrus cover but both were affected by the sampling site. Most of the studied
seed bank characteristics were affected by the sampling depth, but none of them were
affected by the increasing cover of S. cryptandrus . Increasing cover of S. cryptandrus
in the vegetation was associated with an increasing proportion of S. cryptandrus seeds
in the seed bank, and we found a low‐density soil seed bank of the species even in
plots with no S. cryptandrus cover. Our finding that S. cryptandrus forms a massive
soil seed bank, together with the predicted decrease in the precipitation of the summer
months and increase in the frequency of droughts in the region, projects further rapid
spread of the species.
