Multispecies invasion reduces the negative impact of single alien plant species on native flora

Magdalena Lenda*, Piotr Skórka, Johannes Knops, Michał Żmihorski, Renata Gaj, Dawid Moroń, Michał Woyciechowski, Piotr Tryjanowski

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

26 Citations (Scopus)


Aim: In the current Anthropocene, many ecosystems are being simultaneously invaded by multiple alien species. Some of these invasive species become more dominant and have greater environmental impacts than others. If two potentially dominant species invade the same area, the combined impact has been reported to be either (a) domination by one species, that is, the competitive dominance of one invader, or (b) invasion meltdown, where the combined impact is much greater, that is, a synergistic effect. We studied the effects of the invasion of two alien plant species that are known to strongly decrease native plant species diversity: the Persian walnut Juglans regiaand goldenrod Solidago canadensis. Location: We examined native vegetation diversity in abandoned fields (in Poland) where neither species had invaded, only one species had invaded, and both species had invaded. Methods: Field survey data were analysed using generalized linear mixed models and ordination techniques. Results: When goldenrod invaded alone, it caused a larger decrease in species richness and cover (74%) than when walnut invaded alone (58%). When walnut and goldenrod co-occurred in abandoned fields, walnut was dominant and strongly decreased goldenrod density by 87%. However, the combined impact on native species diversity was much lower (15% decrease in native plant diversity) than when either goldenrod or walnut invaded alone. Main conclusions: In contrast to many other studies, our study does not support the occurrence of an invasion meltdown. Instead, our results show that even when one invader dominates, its negative effect on plant diversity can be strongly modified by the presence of another invasive species.

Original languageEnglish
Pages (from-to)951-962
Number of pages12
JournalDiversity and Distributions
Issue number6
Publication statusPublished - Jun 2019
Externally publishedYes


  • biodiversity
  • competition
  • competitive hierarchy
  • dominant invader
  • facilitation
  • invasion ecology
  • invasion meltdown
  • nitrogen
  • theory of coexistence


Dive into the research topics of 'Multispecies invasion reduces the negative impact of single alien plant species on native flora'. Together they form a unique fingerprint.

Cite this