Dai risultati di questo studio sembra che specie diverse di orchidee che vivono nella stesso ambiente entrano in simbiosi con colonie micorrizziche differenti. Questo porterebbe ad una forte segregazione spaziale, suggerendo che i funghi micorrizzici sono dei fattori importanti che guidano la ripartizione delle nicche ambientali nelle orchidee terrestri, e possono inoltre contribuire alla coesistenza di specie diverse.
Hans Jacquemyn, Rein Brys, Vincent S. F. T. Merckx, Michael Waud, Bart Lievens, Thorsten Wiegand: Coexisting orchid species have distinct mycorrhizal communities and display strong spatial segregation
Summary
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.
_________________ Luca«Nomina si nescis, perit et cognito rerum» - Se si ignora il nome delle cose, se ne perde anche la conoscenza. C. Linnaeus, Philosophia botanica (1751) «I was much struck how entirely vague and arbitrary is the distinction between species and varieties. Charles Darwin, On the Origin of Species (1859)«This disagreement regarding bee orchid diversity represents a particularly extreme example of a phenomenon that frequently afflicts taxonomy - a dichotomy between researchers who divide natural variation into as many units as possible (splitters) and others who aggregate those subtly different units into entities that they consider to be either more easily recognised or more biologically meaningful (lumpers)» - R.M. Bateman
«Un fiore, anche il più insignificante, è la mirabile risultanza di un collaudato progetto genomico, di precisi equilibri ecologici, dell'azione congiunta del sole, del terreno, della pioggia e della rugiada, del vento e degli insetti impollinatori. Quale unica specie consapevole della complessità di questi processi e della preziosità del risultante dono, è nostro dovere promuoverne la conoscenza e prodigarci per la sua protezione» - G. Sciarretta Nomenclatura GIROS - Biodiversity Heritage Library - IPNI, International Plant Names Index - Kew Gardens Checklist
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