Invasive trees rely more on mycorrhizas, countering the ideal-weed hypothesis

The ideal-weed hypothesis predicts that invasive plants should be less dependent on mutualisms. However, evidence in favor of or against this hypothesis comes mainly from observational studies. Here, we experimentally tested this hypothesis using a two-factor greenhouse experiment, comparing the see...

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Detalhes bibliográficos
Autores: Moyano, Jaime, Rodriguez Cabal, Mariano Alberto, Nuñez, Martin Andres
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2021
País:Argentina
Recursos:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/183687
Acesso em linha:http://hdl.handle.net/11336/183687
Access Level:acceso abierto
Palavra-chave:ECTOMYCORRHIZAL FUNGI
FACILITATION
MUTUALISTS
PINUS
PLANT INVASIONS
SEED MASS
SEEDLING GROWTH
https://purl.org/becyt/ford/1.6
https://purl.org/becyt/ford/1
Descrição
Resumo:The ideal-weed hypothesis predicts that invasive plants should be less dependent on mutualisms. However, evidence in favor of or against this hypothesis comes mainly from observational studies. Here, we experimentally tested this hypothesis using a two-factor greenhouse experiment, comparing the seedling growth response of different Pinus species (varying in invasiveness) to ectomycorrhizal fungal inoculation. Most species showed no response until they were 6 mo old, at which point inoculation increased growth between 10 and 260% among the different species. This growth response was higher for species with lower seed mass, higher dispersal ability, higher Z score (a proxy for invasiveness) and higher number of naturalized regions, all of which correspond to higher invasiveness. Our results show that timing is a crucial factor when comparing mycorrhizal dependency of different species. Dependence on mutualistic microorganisms could be part of a strategy in which invasive species produce smaller seeds, in greater number, which can disperse further, but where seedlings are more reliant on mycorrhizas to improve access to water, nutrients, and protection from pathogens. Our results suggest that reliance on mutualisms may enhance, rather than limit, nonnative species in their ability to spread, establish, and colonize.