Competitive effect of the invasive Centaurea melitensis on the chilean native Helenium aromaticum

SOTES GJ; CAVIERES LA; GÓMEZ-GONZÁLEZ S

Olmué

Congreso; XIII International Mediterranean Ecosystems Conference; 2014

The evolution ofthe increased competitive ability of invasive plants (EICA) after new rangecolonization has been proposed as a cause of the invasive success. In addition,the success of some invasive species lies in a climatic match between invadeand originating region. In this context, several invasive species in centralChile come from similar climatic areas with Mediterranean characteristics. Anexample of this is Centaurea melitensis (Asteraceae), which covers largeareas in the Chilean matorral. This suggests that it could competitivelydisplace native plants, but their impact has not been evaluated. The objectiveof this study was to evaluate if the invasive C. melitensis in state ofseed and seedling competes with the chilean native Helenium aromaticum (Asteraceae),and if this competitive effect varies depending on the origin of the populationof the invasive; Spain vs. Chile. Thepercentage and velocity of germination of H.aromaticum and C. melitensis seeds originating in Spain and Chilewere evaluated in vitro. Competitionat the level of seedlings was evaluated growing both single species and peersin pots of 500 ml. After 5 months was obtained biomass reached for eachcondition and the relative rate of interaction was calculated. There was no significanteffect of competition between species on germination. At the level ofseedlings, the biomass of H. aromaticum is significantly reduced in thepresence of C. melitensis both Spain and Chile. However, it was notfound an increased in the competitive capacity in plants of C. melitensisfrom Chile. This indicates that,invasive C. melitensis plants could displace native congeners alteringthe composition of matorral vegetation; but this would not be happening through a competitivecapacity acquired post invasion.