Species identity and diversity effects on invasion resistance of tropical freshwater plant communities

Abstract

Biotic resistance mediated by native plant diversity has long been hypothesized to reduce the success of invading plant species in terrestrial systems in temperate regions. However, still little is known about the mechanisms driving invasion patterns in other biomes or latitudes. We help to fill this gap by investigating how native plant community presence and diversity, and the presence of native phylogenetically closely related species to an invader, would affect invader Hydrilla verticillata establishment success in tropical freshwater submerged plant communities. The presence of a native community suppressed the growth of H. verticillata, but did not prevent its colonisation. Invader growth was negatively affected by native plant productivity, but independent of native species richness and phylogenetic relatedness to the invader. Native plant production was not related to native species richness in our study. We show that resistance in these tropical aquatic submerged plant communities is mainly driven by the presence and biomass of a native community independent of native species diversity. Our study illustrates that resistance provided by these tropical freshwater submerged plant communities to invasive species contrasts to resistance described for other ecosystems. This emphasizes the need to include understudied systems when predicting patterns of species invasiveness and ecosystem invasibility across biomes.Biological invasions represent a key component of human-induced global changes, and increasingly challenge the conservation and management of freshwater, marine and terrestrial ecosystems across the globe 1,2 . Although our knowledge on invasion ecology has increased considerably over the last decades, research has been strongly biased towards certain geographical regions and ecosystems 3-6 . Most of our understanding about the process, patterns and mechanisms of invasions emerges from studies performed in temperate terrestrial systems, whereas the impact on megadiverse tropical regions -that together harbor the greatest part of the Earth's biodiversityremains surprisingly understudied 3,5,7,8 . Similarly, freshwater systems, which are both hotspots of biodiversity and have been heavily impacted by human activities, are the least studied among ecosystem realms 3,9 . The lack of information is especially problematic because tropical systems are among the most threatened on earth, and freshwater ecosystems show the strongest biodiversity decline 10-12 . Understanding the mechanisms underlying the success or failure of invasions is essential for possible prevention, control or management of invasive species.Studies have suggested that tropical systems may be less susceptible to invasions than temperate systems 13,14 . An important rationale for this idea is that the highly species-rich native communities generally found in tropical systems, may resist invasions through biotic processes such as competition 15 . The biotic resistance hypothesis predicts that, during alien plant invasion, more diverse commu...

Vegetation and soil recovery following Eucalyptus grandis removal in Limpopo Province, South Africa

“…Petruzzella et al. (2020) reported that mature and undisturbed native plant communities with rich plant diversity (as was observed at the uninvaded treatment) provide greater resistance to alien plant invasion. More research is required to investigate why some ecosystems are resistant to alien plant invasion.…”

“…Several invasion resistance factors can explain why E. grandis species were not present in the uninvaded sites. Such factors include (a) resistance of native ecosystem to plant invasion due to biotic resistance mediated by high plant diversity, and (b) allelopathic effects of some native species (Dutt, 2018; Petruzzella et al., 2020). Petruzzella et al.…”

“…Several invasion resistance factors can explain why E. grandis species were not present in the uninvaded sites. Such factors include (a) resistance of native ecosystem to plant invasion due to biotic resistance mediated by high plant diversity, and (b) allelopathic effects of some native species (Dutt, 2018;Petruzzella et al, 2020). Petruzzella et al (2020) reported that mature and undisturbed native plant communities with rich plant diversity (as was observed at the uninvaded treatment) provide greater resistance to alien plant invasion.…”

“…Such factors include (a) resistance of native ecosystem to plant invasion due to biotic resistance mediated by high plant diversity, and (b) allelopathic effects of some native species (Dutt, 2018;Petruzzella et al, 2020). Petruzzella et al (2020) reported that mature and undisturbed native plant communities with rich plant diversity (as was observed at the uninvaded treatment) provide greater resistance to alien plant invasion. More research is required to investigate why some ecosystems are resistant to alien plant invasion.…”

Impacts of the Invasive Impatiens glandulifera: Lessons Learned from One of Europe’s Top Invasive Species

“…The biotic resistance hypothesis asserts that communities which are more diverse are less susceptible to biological invasions than less diverse communities [23,24]. The riparian habitats dominated by I. glandulifera are prone to invasives, in part due to their high disturbance regimes [25].…”