Isabel LaLonde

Assessing the Seedbank Composition of Inland Lakeshores Invaded by Typha x Glauca

The ability of native plants to regenerate following removal of the hybrid cattail, Typha x Glauca, depends on the quality of the existing seedbank in a given area, and dense Typha stands may degrade the seedbank. Studies involving seedbank assessment in areas invaded by Typha have been conducted in coastal wetland ecosystems but not in inland lake ecosystems. In this study, soil cores were taken from three sites on inland lakeshores in southeastern Minnesota for the purpose of assessing their seedbank composition. Two of these sites were invaded with Typha x Glauca and one was uninvaded. The soil samples were placed in trays on a laboratory growth bench under two different moisture level treatments. The seedlings that emerged were then identified to the lowest possible taxonomic level. A total of six plant species emerged across the three sites that were sampled. The first invaded site contained only Typha in its seedbank. The second invaded site had a high density of Typha seedlings, but also the highest density and richness of other species. The uninvaded site had a low density of both Typha seedlings and other species and lower species richness. These results indicate that some invaded lakeshores may not be able to recover from their seedbank alone following control of hybrid cattail. Further research is needed to determine what environmental factors may have contributed to the differences in seedbank composition between these three sites.