Biotic interactions drive ecosystem responses to exotic plant invaders

Area of Science:

• Ecology
• Environmental Science
• Biogeochemistry

Background:

• Plant invasions often increase ecosystem process rates.
• The drivers of these changes—productivity, species traits, or novel interactions—remain unclear.

Purpose of the Study:

• To quantify the relative importance of exotic plant dominance, traits, soil biota, and herbivores in driving ecosystem carbon cycling.
• To understand how plant traits mediate interactions between exotic species and novel biota.

Main Methods:

• Experimental manipulation of plant communities with varying exotic dominance, traits, soil biota, and invertebrate herbivores.
• Measurement of ecosystem carbon cycling indicators, including soil carbon turnover.

Main Results:

• Interactions with soil biota and herbivores were the strongest drivers of exotic plant impacts on carbon cycling.
• Plant traits influenced how exotic species interacted with novel soil biota and herbivores.
• Soil carbon turnover was particularly sensitive to these novel biological interactions.

Conclusions:

• Novel biological interactions with exotic species are a critical driver of ecosystem transformation.
• Exotic plant traits modulate these interactions, influencing ecosystem-level changes.
• Understanding these novel interactions is key to predicting invasion impacts.