Invasive Species Dynamics in Forest Ecosystems

Invasive species represent a major threat to forest ecosystems worldwide by altering community composition, disrupting ecosystem functions and incurring substantial economic costs. Their successful establishment depends on factors such as propagule pressure, the suitability and availability of host species, and the resistance offered by native biotic communities. Primary pathways of introduction include international trade in live plants and wood products, transport via packaging materials and accidental transfer through global travel networks. Once introduced, invaders can spread rapidly aided by climate change and landscape disturbance, leading to shifts in forest structure, declines in native biodiversity, changes to nutrient cycling and increased susceptibility to further pest outbreaks. Management strategies span prevention, early detection, eradication and long-term containment, but remain challenged by insufficient surveillance, incomplete understanding of invasion mechanisms and limited cross-boundary coordination. Recent advances in mechanistic modelling, high-resolution mapping of introduction pathways and experimental approaches to predict host susceptibility are informing risk assessments and guiding more targeted biosecurity protocols. Integrating ecological theory with practical management has become essential to mitigate current invasions and anticipate future threats in a changing world.

Research from Nature Portfolio

Recent studies have demonstrated that regional plant diversity is a primary driver of insect invasions at continental scales, with both native and non-native tree richness explaining much of the variation in established insect species across world regions. This work revisits the long-standing hypothesis that more diverse forests offer more potential niches and propagule pathways for invaders, revealing that climatic and geographical factors often act indirectly through their influence on host plant assemblages. The findings underscore the importance of managing plant trade and diversity patterns to reduce invasion risk in forest habitats.

Invasive Species Dynamics in Forest Ecosystems publication trend

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

Technical terms

Propagule pressure: The quantity, frequency and variety of organisms introduced to a new environment, influencing establishment probability.

Host availability: The presence and abundance of suitable native or non-native plant species that invaders can exploit.

Biotic resistance: The capacity of existing communities to repel or limit the establishment of non-native species through predation, competition or disease.

Pathway: A route or mechanism by which an organism is transported from its native range to a new region (e.g. trade in live plants).

Mechanistic modelling: The use of mathematical or computational representations of ecological processes to predict invasion dynamics.

References

1. Higher tree species richness and diversity in urban areas than in forests: Implications for host availability for invasive tree pests and pathogens. Landscape and Urban Planning (2024).
2. Nonnative forest insects and pathogens in the United States: Impacts and policy options. Ecological Applications (2016).
3. Depletion of heterogeneous source species pools predicts future invasion rates. Journal of Applied Ecology (2017).
4. Plant diversity drives global patterns of insect invasions. Scientific Reports (2018).
5. The worldwide airline network and the dispersal of exotic species: 2007–2010. Ecography (2009).