Heterogeneous environments shape invader impacts: integrating environmental, structural and functional effects by...

Area of Science:

• Ecology
• Environmental Science
• Remote Sensing

Background:

• Ecosystem spatial heterogeneity influences plant performance and can be amplified by plant feedbacks.
• Exotic plant invasions significantly alter native ecosystems, but integrating geospatial data with plant interactions remains a challenge.

Purpose of the Study:

• To develop a model predicting small-scale spatial variation of nitrogen (N) cycle tracers in native species.
• To investigate the impact of environmental heterogeneity on invasive species' effects.

Main Methods:

• Combined remotely sensed data (topography, vegetation cover) with a functional tracer (δ¹⁵N).
• Utilized a generalized additive mixed model for analysis.
• Focused on an N₂-fixing acacia invasion in a nutrient-poor dune ecosystem.

Main Results:

• Successfully predicted foliar δ¹⁵N variation in a non-fixing native species using geospatial data (R² = 0.6).
• Demonstrated that heterogeneous environments modulate the impacts of invasive species.

Conclusions:

• Linking remote sensing with biological tracers advances understanding of spatially structured ecosystems.
• The model provides a novel approach to assess invader impacts in heterogeneous landscapes.