Distinct invasion strategies operating within a natural annual plant system.
Alien plant species are known to have a wide range of impacts on recipient communities, from resident species' exclusions to coexistence with resident species. It remains unclear; however, if this variety of impacts is due to different invader strategies, features of recipient communities or both. To test this, we examined multiple plant invasions of a single ecosystem in southwestern Australia. We used extensive community data to calculate pairwise segregation between target alien species and many co-occurring species. We related segregation to species' positions along community trait hierarchies and identified at least two distinct invasion strategies: 'exploiters' which occupy high positions along key trait hierarchies and reduce local native species diversity (particularly in nutrient-enriched situations), and 'coexisters' who occupy intermediate trait positions and have no discernable impact on native diversity. We conclude that trait hierarchies, linked to measures of competition, can provide valuable insights about the processes driving different invasion outcomes.
School of Biological Sciences, The University of Queensland, Brisbane, Queensland, 4072, Australia.
Hao Ran
HR
Lai
Margaret M
MM
Mayfield
Justine M
JM
Gay-des-Combes
Thomas
T
Spiegelberger
John M
JM
Dwyer
D027481:Araliaceae / Q000502:physiology; D019659:Asteraceae / Q000502:physiology; D044822:Biodiversity; D017753:Ecosystem; D058865:Introduced Species; D008954:Models, Biological; D010944:Plants / Q000145:classification*; D006109:Poaceae / Q000502:physiology; D029622:Portulacaceae / Q000502:physiology; D019655:Quantitative Trait, Heritable; D028083:Scrophulariaceae / Q000502:physiology; D014904:Western Australia
Functional traits; York gum woodlands; nutrient enrichment; species invasions; trait hierarchies