Niche Dynamics in Ecological Invasions

Ecological invasions arise when species establish, spread and persist in regions beyond their native ranges. Key to understanding this process is the concept of the ecological niche, defined by the suite of environmental conditions under which a species can survive and reproduce. Two principal niche categories are distinguished: the fundamental niche, representing the full spectrum of abiotic conditions tolerable in the absence of biotic constraints, and the realised niche, the subset of those conditions actually occupied when competition, predation and other factors are in play. In many invasions, species either conserve their ancestral niches or undergo niche shifts, expanding into environments unavailable in their native habitats. Niche dynamics may be driven by rapid microevolution, plastic responses, or the release from former competitors. Accurately projecting invasion risk requires models that capture both fundamental tolerances and realised distributions, accounting for environmental non-equilibrium and potential adaptive changes. Practical applications range from early warning of high-risk regions to informing management strategies that limit further spread under climate change.

Research from Nature Portfolio

Recent studies have harnessed ecophysiological mechanistic modelling to improve predictions of avian invasions. By integrating thermal traits, metabolic rates and feather insulation properties, mechanistic models delineate fundamental thermal niches and forecast potential distributions outside current realised ranges. These models reveal that functional traits, rather than solely correlative climatic envelopes, offer robust projections of invasion risk and can guide policy to prioritise surveillance and rapid response. Other work has compared realised climatic niches of amphibian invaders between native and introduced ranges, uncovering varying degrees of niche conservatism, niche shift and environmental non-equilibrium. Such shifts undermine reciprocal transferability of correlative niche models calibrated on either range alone. The solution advanced is to combine occurrence data from both native and invaded regions and to regularly reassess niche changes as invasions progress, ensuring models remain aligned with ongoing ecological and evolutionary dynamics.

Niche Dynamics in Ecological Invasions publication trend

The graph below shows the total number of articles in niche dynamics in ecological invasions across all publications each year (not limited to Nature Index journals).

Technical terms

Fundamental niche: The full range of abiotic conditions permitting a species’ survival and reproduction in the absence of biotic interactions.

Realised niche: The actual conditions occupied by a species, after accounting for competition, predation and other ecological constraints.

Niche conservatism: The tendency of a species to retain ancestral ecological requirements during range shifts.

Niche shift: An alteration in the realised niche of a species, allowing survival in novel environmental conditions beyond the ancestral niche.

Mechanistic modelling: An approach that uses physiological and functional trait data to predict species’ tolerances and potential distributions.

Species distribution model (SDM): A correlative modelling technique that relates occurrence records to environmental predictors to estimate species’ potential ranges.

Environmental non-equilibrium: A state in which species’ distributions have not yet fully adjusted to available suitable habitats, often during early invasion stages.

References

1. Mechanistic models project bird invasions with accuracy. Nature Communications (2023).
2. Niche shifts and environmental non-equilibrium undermine the usefulness of ecological niche models for invasion risk assessments. Scientific Reports (2020).
3. Herbarium specimens reveal a cryptic invasion of polyploid Centaurea stoebe in Europe. New Phytologist (2024).
4. Can species distribution models really predict the expansion of invasive species?. PLOS ONE (2018).