Evidence for functional state transitions in intensively-managed soil ecosystems

Area of Science:

• Soil science
• Ecology
• Environmental science

Background:

• Soils are crucial for ecosystem function and food security.
• Soil resilience is key to understanding ecosystem stability.
• Soils serve as models for studying complex system resilience.

Purpose of the Study:

• To investigate soil resilience to extreme drying and re-wetting cycles.
• To determine if land-use history influences soil tipping points into alternative stable states.
• To assess the impact of historical management on soil functional shifts.

Main Methods:

• Experimental plots with distinct land-use histories (grass, arable, fallow) were used.
• Soils underwent repeated cycles of extreme drying and re-wetting.
• Soil respiration responses to a complex carbon substrate were measured before and after disturbance.

Main Results:

• Initial disturbances impaired microbial function across all soil types.
• Grassland soils, and those with recent grass history, demonstrated resilience, returning to their prior functional state.
• Arable soils exhibited reduced resilience, shifting towards a functional state similar to fallow soils.
• Management history significantly influenced the soil's response to repeated stress.

Conclusions:

• Repeated extreme drying and re-wetting can induce persistent functional shifts in soils.
• Land-use history, particularly grassland management, enhances soil resilience.
• Arable soil management may lead to decreased resilience and functional instability.