BACKGROUND: Plant facilitation occurs when the presence of a plant (i.e. a nurse plant) modifies the environment, making it more favourable for the establishment and survival of other species (i.e. facilitated plants), which can germinate and grow nearby. Facilitative associations can be maintained or turned into competition as the facilitated seedling grows. According to the competition-relatedness hypothesis that suggests that closely related species tend to compete more, facilitation turns into competition between phylogenetically close species. However, some examples of facilitation between congeneric species, which are supposed to be closely related species, have been found in nature. SCOPE: In this work, some examples of congeneric facilitation and subsequent coexistence are reviewed and an attempt is made to explain those exceptions to the competition-relatedness hypothesis. CONCLUSIONS: Two mechanisms are proposed that can switch the facilitation-competition balance: trait divergence and indirect interactions. When traits have diverged within the genus, the niche overlap is reduced and competition relaxed, thus allowing the coexistence of congeneric species. The presence of third interplayers (mycorrhizal fungi, seed dispersers, pollinators or pathogens) participating in the interaction between plants can alleviate the competition or enhance the reproduction and allow the coexistence of species that could not coexist in their absence.
BACKGROUND: Plant facilitation occurs when the presence of a plant (i.e. a nurse plant) modifies the environment, making it more favourable for the establishment and survival of other species (i.e. facilitated plants), which can germinate and grow nearby. Facilitative associations can be maintained or turned into competition as the facilitated seedling grows. According to the competition-relatedness hypothesis that suggests that closely related species tend to compete more, facilitation turns into competition between phylogenetically close species. However, some examples of facilitation between congeneric species, which are supposed to be closely related species, have been found in nature. SCOPE: In this work, some examples of congeneric facilitation and subsequent coexistence are reviewed and an attempt is made to explain those exceptions to the competition-relatedness hypothesis. CONCLUSIONS: Two mechanisms are proposed that can switch the facilitation-competition balance: trait divergence and indirect interactions. When traits have diverged within the genus, the niche overlap is reduced and competition relaxed, thus allowing the coexistence of congeneric species. The presence of third interplayers (mycorrhizal fungi, seed dispersers, pollinators or pathogens) participating in the interaction between plants can alleviate the competition or enhance the reproduction and allow the coexistence of species that could not coexist in their absence.
Authors: María Uriarte; Nathan G Swenson; Robin L Chazdon; Liza S Comita; W John Kress; David Erickson; Jimena Forero-Montaña; Jess K Zimmerman; Jill Thompson Journal: Ecol Lett Date: 2010-11-05 Impact factor: 9.492
Authors: E Toby Kiers; Marie Duhamel; Yugandhar Beesetty; Jerry A Mensah; Oscar Franken; Erik Verbruggen; Carl R Fellbaum; George A Kowalchuk; Miranda M Hart; Alberto Bago; Todd M Palmer; Stuart A West; Philippe Vandenkoornhuyse; Jan Jansa; Heike Bücking Journal: Science Date: 2011-08-12 Impact factor: 47.728
Authors: Hans Jacquemyn; Vincent Merckx; Rein Brys; Daniel Tyteca; Bruno P A Cammue; Olivier Honnay; Bart Lievens Journal: New Phytol Date: 2011-06-13 Impact factor: 10.151