Dispersal potential and early growth in 14 tropical mangroves: do early life history traits correlate with patterns of adult distribution?

1 We characterized the dispersal potential and early growth traits of 14 tropical mangrove species in experiments where diaspores were immersed in various solutions of seawater and subsequently stranded onto surfaces with the same salinity. 2 Viviparous and non-viviparous species had similar buoyancy, seed weight and rates of root and shoot initiation, as well as early growth and salinity tolerance. This trait convergence may be related to selection against small, dormant diaspores in the unstable regeneration niche. 3 Differences in dispersal potential and early growth of 12 species were compared with known patterns of distribution (across the shore, along estuaries, regional occurrence and continental range size) to test if tidal sorting of diaspores could account for adult spatial patterns. 4 Diaspore buoyancy, orientation, lateral root initiation, shoot initiation and early shoot extension differed among species but none correlated with adult zonation across the shore or along estuaries. However, some back-shore species had diaspores that were buoyant and were slow to initiate lateral roots and shoots. Patterns of early growth were partially related to the distribution along estuaries but salinity responses contributed to this zonation in only three species. 5 Regional distributions were unrelated to dispersal potential. However, the tendency of infrequent species to show slow growth in full seawater may account for the under-saturation of species in estuaries with appropriate habitats. The range size of the tropical mangroves appears unrelated to their dispersal potential and early growth traits. 6 Early life history traits of 12 mangroves showed poor correlation with patterns of adult distribution across all spatial scales. Traits related to establishment were., however, stronger predictors of distribution than those associated with dispersal.