The role of seed germination in the invasion process of Honey locust (Gleditsia triacanthos L., Fabaceae): comparison with a native con-familial

FERRERAS, A.,E.; FUNES G; GALETTO L.

PLANT SPECIES BIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2015 vol. 30 p. 126 - 136

0913-557X

: Identifying plant traits that promote invasiveness has been a major goal in invasion ecology. Germination plays a central role in plant life cycle and could therefore be a key trait in determining species invasiveness. In this study, seed germination of two con-familial, co-occurring species that share ecological characteristics, the exotic invasive Gleditsia triacanthos L. and the native Acacia aroma Gillies ex. Hook. & Arn., was compared. Seeds were obtained from individuals of three localities in the Chaco Serrano region of Córdoba, Argentina. Percentage of seed germination and mean germination time were recorded for chemically and mechanically scarified seeds, and the first variable was also recorded for seeds subjected to the following treatments: passage through the digestive tract of dispersers, fire simulations, fire simulation plus mechanical scarification, seed longevity, and dormancy break over time. In general, both species showed similar germination percentage. However, the exotic species had higher germination percentage at simulated fire intensities plus mechanical scarification and when subjected to experiments of dormancy break over time. On the other hand, the native species had shorter mean germination time. The greater percentage of seed germination of the exotic species than the native might be triggering its spread, whereas the shorter mean germination time might be hindering its expansion to more arid regions. A detailed analysis of the germination process would help to better understand the expansion of exotic species and to gather useful knowledge for their management.