Intraspecific variation of seed floating ability in **Sparganium emersum** suggests a bimodal dispersal strategy

Pollux, B.J.A.; Verbruggen, E.; Van Groenendael, J.M.; Ouborg, N.J.

doi:10.1016/J.AQUABOT.2008.07.002

Title

Intraspecific variation of seed floating ability in **Sparganium emersum** suggests a bimodal dispersal strategy

Author

Pollux, B.J.A.

Verbruggen, E.

Van Groenendael, J.M.

Ouborg, N.J.

Abstract

Water-mediated spread of seeds (hydrochory) plays an important role in the dispersal of aquatic plants. In this study we investigate intraspecific variation in floating ability and germination capacity of Sparganium emersum seeds in relation to seed mass, within three natural populations along the Rur River (the NetherlandsGermany). Our results suggest that S. emersum produces two types of seeds: (i) short-floating seeds (SFS) that sink within 4 weeks (approximately 71% of all seeds), and (ii) long-floating seeds (LFS) that float at least for 6 months (approximately 28% of all seeds). Our study further shows that short-floating seeds display a significantly higher germination (%) (SFS = 89.9% vs LFS = 32.6%), a faster germination rate (SFS = 8.71 ± 3.3 vs LFS = 9.32 ± 3.1 days to germination) and a higher mean seed mass (SFS = 15.17 ± 4.5 vs LFS = 11.25 ± 3.8 mg), compared to long-floating seeds. It is argued that the production of these two types of seeds by S. emersum plants, each type with a different potential for water-mediated dispersal, represents a bimodal hydrochoric dispersal strategy.

Language

English

Source (journal)

Aquatic botany. - Amsterdam

Publication

Amsterdam : 2009

ISSN

0304-3770

DOI

10.1016/J.AQUABOT.2008.07.002

Volume/pages

90 :2 (2009) , p. 199-203