Earthworms Coordinate Soil Biota to Improve Multiple Ecosystem Functions.

Area of Science:

• Soil Ecology
• Ecosystem Functionality
• Sustainable Agriculture

Background:

• Earthworms, traditionally viewed as beneficial soil engineers, are increasingly linked to negative impacts like increased greenhouse gas emissions and reduced soil biodiversity.
• Understanding earthworm effects on ecosystem multifunctionality, the ability to provide multiple functions simultaneously, is crucial for ecological and agricultural contexts.

Purpose of the Study:

• To investigate the direct and indirect impacts of earthworms on 21 ecosystem functions over 13 years using a field experiment.
• To evaluate earthworm contributions to ecological multifunctionality within a rice-wheat cropping system.

Main Methods:

• A long-term field experiment (13 years) was conducted to monitor 21 ecosystem functions.
• Data analysis focused on distinguishing direct and indirect effects of earthworm presence on multifunctionality.
• Investigated the role of soil community composition, soil properties, and taxonomic diversity in mediating earthworm impacts.

Main Results:

• Earthworm presence generally enhanced ecosystem multifunctionality, predominantly through indirect rather than direct effects.
• Earthworms promoted multifunctionality by shifting soil communities towards a bacterial energy channel and strengthening microbial and microfaunal associations.
• Changes in soil physical structure, pH, and taxonomic diversity were not significantly related to enhanced multifunctionality.

Conclusions:

• The coordinated activity of earthworms and associated soil biota maintains high levels of ecosystem multifunctionality in rice-wheat systems.
• Management strategies focusing on crop residue input and reduced soil disturbance can promote beneficial earthworm activities.
• Supporting earthworm populations is vital for enhancing ecosystem services essential for sustainable agriculture.