Response of native and non-native ruderals to natural and human disturbance

CHIUFFO, MARIANA C.; COCK, MARINA C.; PRINA, ANÍBAL O.; HIERRO, JOSÉ L.

BIOLOGICAL INVASIONS

SPRINGER

Año: 2018

1387-3547

The ruderal strategy is widely sharedamong non-native plants, providing a general explanationfor the commonly observed positive effects ofdisturbance on invasions. How native ruderals respondto disturbance and how their abundance compares tothat of non-native ruderals remains, however, poorlyunderstood. Similarly, little is known about the rolethat disturbance type plays in the coexistence betweennative and non-native ruderals. We proposed thatnatural disturbance favors native over non-nativeruderals, whereas novel anthropogenic disturbancefavors non-natives over natives. To assess our generalhypothesis, we conducted extensive field samplings inwhich we measured relative abundance, richness, anddiversity of native and non-native ruderals in sites withnatural and anthropogenic disturbance in centralArgentina, a system where the ruderal strategy iscommon to a large number of native and non-nativespecies. We found that natives dominated ruderalcommunities growing in recently burned grasslands,whereas non-natives dominated in roadsides. Additionally,the richness and diversity of native ruderalspecies were much greater than those of non-natives insites with fire and in sites with grazing, but speciesrichness and diversity did not differ between groups inroadsides. Because vegetation evolved with fire in our system and, in contrast, the construction and maintenanceof roads is recent in it, these results support ourhypothesis. Our work indicates that the ruderalstrategy does not seem to suffice to explain whydisturbance facilitates invasions. According to ourdata, species origin interacts with disturbance type todetermine dominance in communities with coexistingnative and non-native ruderals.