Lenka Moravcová¹, Margherita Gioria¹, Hana Skálová¹ and Petr Pyšek^1,2

¹Institute of Botany, The Czech Academy of Sciences, Zámek 1, CZ-252 43 Průhonice, Czech Republic
²Department of Ecology, Faculty of Science, Charles University, Viničná 7, CZ-128 44 Prague, Czech Republic

e-mail: lenka.moravcova@ibot.cas.cz

By comparing naturalized alien species with natives, we can assess the role that seasonal and short-term seed bank dynamics play in the naturalization process, and whether the naturalized species are provided with an advantage following an introduction to the new region. Here, we performed standardized burial experiments to test differences in the seed survival dynamics of naturalized alien plant species in the Czech Republic (by definition, this set of species includes some invasive taxa that are a subset of naturalized species; Richardson et al. 2000, Blackburn et al. 2011) and their native close relatives (congeners) to minimize the variation and possible biases due to species’ phylogenies, life histories and habitat affinities. The seeds of 13 congeneric pairs, selected to meet the above criteria, were collected in the field in the Czech Republic in the autumn of 2015, and used in a burial experiment in the common garden of the Institute of Botany in Průhonice. The collected seeds were initially tested for viability using germination tests and then buried in nylon bags in the soil. The seeds were excavated twice a year (in April and October, for a spring and an autumn sample, respectively). The fraction of germinated or decayed seeds, and non-germinated but viable seed, was determined in each sample. The experiment ran for three years (2016–2018). We found a slightly higher seed bank density in alien species in comparison with native species, the difference being more obvious during spring. Our results are the first to quantify, in such a detail and extent, the process of seed bank depletion and seasonal dynamics, and will allow for the possbility to discuss implications of the differences between alien and native species seed bank dynamics.

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Richardson D. M., Pyšek P., Rejmánek M., Barbour M. G., Panetta F. D. & West C. J. (2000) Naturalization and invasion of alien plants: concepts and definitions. Diversity Distrib. 6: 93–107.