Invasive Species Interactions in Ecological Communities

Invasive species often arrive and establish in ecological communities where they interact not only with native biota but also with one another. These interactions can be competitive, where invaders suppress each other or native species through resource depletion, or facilitative, in which one invader alters habitat conditions, nutrient cycling or trophic relationships in a way that benefits subsequent invaders. When facilitation dominates, a process known as invasional meltdown can emerge, amplifying impacts on ecosystem structure and function. Interactions among invaders may also drive secondary invasions, whereby a primary invader modifies ecosystem properties to enable the establishment or spread of additional exotic species. Recent advances have applied network models, experimental mesocosms and field manipulations to reveal how invader combinations shape community assembly, influence food-web topology and determine ecological resilience. Such studies highlight that multiple invaders often have non-additive effects, requiring management strategies that consider interaction networks rather than treating each species in isolation. A deeper understanding of these dynamics has global relevance for the conservation of biodiversity, the restoration of ecosystem processes and the prioritisation of control efforts in terrestrial, freshwater and marine environments.

Research from Nature Portfolio

Recent studies have employed large-scale network models to quantify how virtual invasive species propagate impacts through complex food webs. By simulating the introduction of different trophic types—herbivores, carnivores, omnivores and insectivores—into an offshore island community, researchers demonstrated that responses cluster by taxonomic group yet exhibit unexpected variation at finer taxonomic scales. These findings reveal that while some native taxa may be broadly vulnerable, management can be refined by identifying subgroups most at risk. The use of ecologically realistic propagation criteria in these models provides a predictive framework for anticipating cascading biodiversity losses and guiding targeted interventions.

Invasive Species Interactions in Ecological Communities publication trend

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

Technical terms

Facilitation: A positive interaction in which one species modifies the environment in a way that benefits another species.

Invasional meltdown: A process in which mutual positive interactions among invasive species lead to accelerating impacts on native communities and ecosystem processes.

Secondary invasion: The establishment or spread of a species that is enabled by ecosystem changes induced by a prior invader.

Ecological network: A representation of biotic interactions (such as predation, competition or mutualism) among species in a community, often visualised as nodes and links.

Trophic cascade: Indirect interactions that occur when effects on one trophic level cascade to affect other levels, often altering ecosystem structure.

References

1. Managing multi‐species plant invasions when interactions influence their impact. Frontiers in Ecology and the Environment (2023).
2. Secondary invasion: When invasion success is contingent on other invaders altering the properties of recipient ecosystems. Ecology and Evolution (2017).
3. Structuring evidence for invasional meltdown: broad support but with biases and gaps. Biological Invasions (2017).
4. Whole community invasions and the integration of novel ecosystems. PLOS Computational Biology (2022).
5. Impact of cyber-invasive species on a large ecological network. Scientific Reports (2018).