Side-swiped: Ecological cascades emanating from earthworm invasion

Area of Science:

• Ecology
• Soil Science
• Invasive Species Biology

Background:

• Non-native, invasive earthworms are widespread global soil modifiers.
• Earthworm impacts initiate ecological cascades from mid-trophic levels, distinct from traditional bottom-up or top-down models.
• These alterations fundamentally change soil properties and ecosystem processes.

Purpose of the Study:

• To describe the ecological cascade effects initiated by invasive earthworms.
• To highlight the societal and ecological consequences of earthworm-driven soil alterations.
• To examine the interactions between earthworm-induced changes and other environmental stressors.

Main Methods:

• Review of ecological cascade theory.
• Analysis of earthworm impacts on soil detritus processing.
• Synthesis of research on earthworm-mediated microcascades and macrocascades in North American forests.

Main Results:

• Earthworm activity causes fundamental soil changes (microcascades) including altered morphology, bulk density, nutrient leaching, and surface conditions.
• These microcascades trigger broader societal concerns (macrocascades) affecting CO2 sequestration, disturbance, soil and water quality, and biodiversity.
• Cascade complexes emerge from interactions, influencing climate change adaptation and facilitating other invasive species.

Conclusions:

• Invasive earthworms induce significant, cascading ecological changes globally.
• Earthworm-driven alterations in soil function have far-reaching consequences for ecosystem services and biodiversity.
• Understanding these cascade complexes is crucial for managing invasive earthworm impacts and predicting ecosystem responses to global change.