Co-ordinating Editor: Dr. Suzanne Prober.
Aerial seed bank dynamics and seedling emergence patterns in two annual Mediterranean Asteraceae
Article first published online: 19 JAN 2010
© 2010 International Association for Vegetation Science
Journal of Vegetation Science
Volume 21, Issue 3, pages 541–550, June 2010
How to Cite
Bastida, F., González-Andújar, J.L., Monteagudo, F.J. and Menéndez, J. (2010), Aerial seed bank dynamics and seedling emergence patterns in two annual Mediterranean Asteraceae. Journal of Vegetation Science, 21: 541–550. doi: 10.1111/j.1654-1103.2010.01169.x
- Issue published online: 13 APR 2010
- Article first published online: 19 JAN 2010
- Received 26 June 2009;Accepted 3 December 2009.
- Anacyclus radiatus;
- Chrysanthemum coronarium;
- Seed dispersal;
- Seed release;
- Soil seed bank
Question: We explored the functional significance of seasonal aerial seed banks in two coexisting, heterocarpic annual Asteraceae with dormant (Chrysanthemum coronarium) and non-dormant (Anacyclus radiatus) achenes. We hypothesised that the plant achene pool is a significant component of total seed reserves, and that within-season seedling emergence timing is shaped by achene release patterns.
Location: SW Spain.
Methods: In an observational study, we established temporal achene release patterns. We also quantified the aerial and soil achene pools throughout the release season, and assessed seedling emergence timing. Sowing experiments were used to explore the influence of achene release dynamics on emergence timing, and to establish achene morph-specific patterns of between-year distribution of germination.
Results: Achene release extended from late spring to late autumn (Chrysanthemum), or from early autumn to early winter (Anacyclus). Within species, achene morphs differed in release timing. Only in Chrysanthemum, a small achene fraction seemed to persist in the soil, and between-year germination distribution differed among morphs. In coexisting populations, the Anacyclus plant achene pool was an order of magnitude higher than the soil pool throughout the release season, whereas in Chrysanthemum both pools were of the same magnitude during autumn. Within-year seedling emergence was significantly staggered beneath parent plants compared with the pattern resulting solely from the germination response in soil, with the exception of Chrysanthemum in one of the two study years.
Conclusions: Results suggest that seasonal aerial seed banks are effective within-season, risk-reducing traits in ruderal Mediterranean habitats characteristic of the study species.