Ecosystem Impacts of Invasive Plant Species

Invasive plants disrupt ecosystem structure and function through multiple pathways, including competition for resources, alteration of soil properties and modification of disturbance regimes. By establishing high densities or forming monocultures, invasive species can suppress native biodiversity, alter trophic interactions and change nutrient cycling. For example, shifts in root traits often lead to homogenisation of soil microbial communities, with consequences for decomposition rates and nutrient availability. In many systems, invasive cover reduces native plant richness and can precipitate cascading impacts on invertebrate assemblages and higher trophic levels. Furthermore, allelopathic compounds released by certain invaders inhibit native plant growth and microbial activity, reinforcing invasion success. At broader scales, the composition of invading species—particularly the dominance of one invader—often dictates the magnitude of impact more than variation in environmental context. Emerging research highlights the importance of recipient community characteristics, such as diversity and density, in mediating invasion outcomes. Efforts to manage invasions must therefore integrate knowledge of invader traits, recipient community vulnerability and potential legacy effects on ecosystem processes to inform thresholds for intervention and restoration strategies.

Research from Nature Portfolio

Recent studies have shown that the characteristics of the recipient plant community are the principal determinants of invasion impacts on native richness. Work examining a widespread goldenrod invader across numerous paired plots revealed that variation in native diversity, density and cover accounted for most of the observed positive, neutral or negative consequences for resident species. Climatic factors and invader density played secondary roles, while soil microbial interactions mediated indirect effects. This research underscores that invasion impacts often form a continuum across a species’ range and that management should prioritise maintaining community attributes that buffer against loss of native richness.

Ecosystem Impacts of Invasive Plant Species publication trend

The graph below shows the total number of articles in ecosystem impacts of invasive plant species across all publications each year (not limited to Nature Index journals).

Technical terms

Allelopathy: Chemical inhibition of one plant by compounds released from another, affecting germination or growth.

Specific root length (SRL): Root length per unit mass, indicating potential for resource acquisition.

Root tissue density (RTD): Mass per volume of root tissue, reflecting structural investment versus absorptive capacity.

Richness: Number of different species present in a community.

Evenness: Relative abundance distribution among species, indicating dominance patterns.

References

1. Invasive plants and their root traits are linked to the homogenization of soil microbial communities across the United States. Proceedings of the National Academy of Sciences of the United States of America (2024).
2. Macroscale analyses suggest invasive plant impacts depend more on the composition of invading plants than on environmental context. Global Ecology and Biogeography (2023).
3. Managing for biodiversity: impact and action thresholds for invasive plants in natural ecosystems. NeoBiota (2017).
4. What determines positive, neutral and negative impacts of Solidago canadensis invasion on native plant species richness?. Scientific Reports (2015).
5. Invasive species allelopathy decreases plant growth and soil microbial activity. PLOS ONE (2021).