Abstract
Recruitment by seeds is essential both in vegetation dynamics and in
supporting biodiversity in grasslands. The recruitment by seeds is
feasible in suitable vegetation gaps from the seed rain and/or by
establishment from persistent soil seed banks. Cessation of grassland
management results in litter accumulation, which leads to the decline of
species diversity by the decreased availability of open patches. Low
amounts of litter is often beneficial, while high amounts of litter is
detrimental for seed germination and seedling establishment of
short-lived species. In a designed indoor experiment, we explored the
effect of litter on seedling establishment by germinating six
short-lived Brassicaceae species with both increasing seed mass and
litter cover. We found that both seed mass and litter had significant
effect on germination and establishment of the sown species.
Small-seeded species were significantly negatively affected by the 300
and/or 600 g/m2 litter layers. No negative litter effect was detected for species with high seed masses (Lepidium
spp.). No overall significant positive litter effect was found,
although for most of the species cumulative seedling numbers were not
the highest at the bare soil pots. Our results suggest that the negative
effects of litter are less feasible on the large-seeded short-lived
species than on that of small-seeded ones.
Keywords
Biodiversity, Cruciferae, Litter, Seed size, Germination, Weed control
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