title: Coexisting orchid species have distinct mycorrhizal communities and display strong spatial segregation.
abstract: Because orchids are dependent on mycorrhizal fungi for germination and establishment of seedlings, differences in the mycorrhizal communities associating with orchids can be expected to mediate the abundance, spatial distribution and coexistence of terrestrial orchids in natural communities. We assessed the small-scale spatial distribution of seven orchid species co-occurring in 25 × 25 m plots in two Mediterranean grasslands. In order to characterize the mycorrhizal community associating with each orchid species, 454 pyrosequencing was used. The extent of spatial clustering was assessed using techniques of spatial point pattern analysis. The community of mycorrhizal fungi consisted mainly of members of the Tulasnellaceae, Thelephoraceae and Ceratobasidiaceae, although sporadically members of the Sebacinaceae, Russulaceae and Cortinariaceae were observed. Pronounced differences in mycorrhizal communities were observed between species, whereas strong clustering and significant segregation characterized the spatial distribution of orchid species. However, spatial segregation was not significantly related to phylogenetic dissimilarity of fungal communities. Our results indicate that co-occurring orchid species have distinctive mycorrhizal communities and show strong spatial segregation, suggesting that mycorrhizal fungi are important factors driving niche partitioning in terrestrial orchids and may therefore contribute to orchid coexistence.
authors: KU Leuven, Department of Biology, Laboratory of Plant Population and Conservation Biology, KULeuven, B-3001, Leuven, Belgium.
authors: Hans
authors: H
authors: Jacquemyn
authors: KU Leuven, Department of Biology, Laboratory of Plant Population and Conservation Biology, KULeuven, B-3001, Leuven, Belgium.
authors: Rein
authors: R
authors: Brys
authors: Naturalis Biodiversity Center, Leiden University, PO Box 9514, 2300RA, Leiden, the Netherlands.
authors: Vincent S F T
authors: VSFT
authors: Merckx
authors: KU Leuven, Department of Microbial and Molecular Systems (M2S), Laboratory for Process Microbial Ecology and Bioinspirational Management (PME&BIM), Campus De Nayer, De Nayer Campus, B-2860, Sint-Katelijne-Waver, Belgium.|Scientia Terrae Research Institute, B-2860, Sint-Katelijne-Waver, Belgium.
authors: Michael
authors: M
authors: Waud
authors: KU Leuven, Department of Microbial and Molecular Systems (M2S), Laboratory for Process Microbial Ecology and Bioinspirational Management (PME&BIM), Campus De Nayer, De Nayer Campus, B-2860, Sint-Katelijne-Waver, Belgium.|Scientia Terrae Research Institute, B-2860, Sint-Katelijne-Waver, Belgium.
authors: Bart
authors: B
authors: Lievens
authors: Department of Ecological Modelling, UFZ Helmholtz Centre for Environmental Research, PF 500136, DE-04301, Leipzig, Germany.
authors: Thorsten
authors: T
authors: Wiegand
mesh_terms: D001487:Basidiomycota / Q000145:classification; D017753:Ecosystem; D038821:Mycorrhizae / Q000145:classification; D029595:Orchidaceae / Q000145:classification; D013045:Species Specificity; D013559:Symbiosis
keywords: coexistence; fungi; mycorrhizal orchids; spatial structure; species interactions