Nonrandom spatial structuring of orchids in a hybrid zone of three Orchis species
Article first published online: 28 SEP 2011
© 2011 The Authors. New Phytologist © 2011 New Phytologist Trust
Volume 193, Issue 2, pages 454–464, January 2012
How to Cite
Jacquemyn, H., Brys, R., Honnay, O., Roldán-Ruiz, I., Lievens, B. and Wiegand, T. (2012), Nonrandom spatial structuring of orchids in a hybrid zone of three Orchis species. New Phytologist, 193: 454–464. doi: 10.1111/j.1469-8137.2011.03913.x
- Issue published online: 20 DEC 2011
- Article first published online: 28 SEP 2011
- Received: 8 July 2011, Accepted: 26 August 2011
- mycorrhizal fungi;
- seed germination;
- spatial point pattern analysis
- •Nonrandom species–species associations may arise from a range of factors, including localized dispersal, intra- and interspecific interactions and heterogeneous environmental conditions. Because seed germination and establishment in orchids are critically dependent upon the availability of suitable mycorrhizal fungi, species–species associations in orchids may reflect associations with mycorrhizal fungi.
- •To test this hypothesis, we examined spatial association patterns, mycorrhizal associations and germination success in a hybrid zone containing three species of the genus Orchis (Orchis anthropophora, Orchis militaris and Orchis purpurea).
- •Hybridization occurred predominantly between O. purpurea and O. militaris. The spatial distribution patterns of most pure species and hybrids were independent from each other, except that of O. purpurea and its hybrids. The fungal community composition of established individuals differed significantly between pure species, but not between hybrids and O. purpurea. Seed germination experiments using pure seeds showed that the highest number of protocorms were found in regions where adult individuals were most abundant. In the case of hybrid seeds, germination was restricted to areas where the mother plant was most abundant.
- •Overall, these results suggest that the observed nonrandom spatial distribution of both pure and hybrid plants is dependent on the contingencies of the spatial distribution of suitable mycorrhizal fungi.