Question: How do species traits and abiotic factors influence the extent of
hydrochorous dispersal into and out of a small floodplain area along a freeflowing
river in The Netherlands?
Location: The Kappersbult nature reserve (5310702800N, 613701400E), which is a
floodplain along the Dutch River Drentsche Aa.
Methods: Seeds transported by the river were collected in fine mesh nets for
24 consecutive hours once or twice a week for 1 year, upstream and downstream
of the studied floodplain. Data on the captured seeds were related to
species traits and abiotic factors and species composition in the floodplain.
Results: The floodplain functioned both as a seed source and sink. High levels
of river water seemed to promote seed transport to or from the floodplain.
Seeds of riverbank species occurred significantly more often in the river water
than expected. Net source species had significantly higher seed production,
taller stature and higher seed buoyancy, but lower site elevation than net sink
species. Seed weight was significantly higher for sink species than for other
Conclusion: Our study found that inundation, and therefore more natural
river water management, is a prerequisite for seed transport to and from a
floodplain. The restoration of target floodplain vegetation may be successful for
common species that produce many seeds and grow in proximity to the river.
Consequently, it is expected that the probability of restoring vegetation types
that occur further from the river, such as wet grasslands, by hydrochorous
dispersal is low.