Seed dispersal by small herbivores and tidal water: are they important filters in the assembly of salt-marsh communities?

1. Characteristics of internal seed dispersal (endozoochory) by European Brown Hares were compared with similar dispersal by Brent Geese. Hares deposited more seeds of mid-successional, perennial, high-marsh species than did geese, which deposited more seeds of early successional, annual, low-marsh species. 2. Seed survival and germination of salt-marsh species were higher after ingestion and passage through the digestive system of hares compared with geese. Both hares and geese had a negative effect on the percentage of seeds that germinated in comparison with uningested seeds. 3. Small herbivores (hares and geese) dispersed two orders of magnitude fewer seeds than those dispersed by tidal water. 4. Thus these herbivores are not likely to be important filters (constraints) in community assembly at this salt-marsh site on a coastal island in the Netherlands.