Warming weakens facilitative interactions between decomposers and detritivores, and modifies freshwater ecosystem...

Area of Science:

• Ecology
• Environmental Science
• Microbiology

Background:

• Warming alters biotic interactions and ecosystem functioning.
• Decomposition relies on facilitative interactions between detritivores and microorganisms.
• The impact of warming on these interactions in freshwater ecosystems is not well understood.

Purpose of the Study:

• To investigate the effects of warming on the interactions between detritivores and microorganisms.
• To assess the consequences for freshwater ecosystem functioning.

Main Methods:

• Field experiment using tank bromeliads with manipulated bacteria and macroinvertebrate presence.
• Ambient and warming scenarios were applied.
• Effects on microbial communities and ecosystem functions (decomposition, nutrient flux) were analyzed.

Main Results:

• Bacterial density was higher with macroinvertebrates present.
• Warming decreased bacterial density by 54% when macroinvertebrates were present.
• Warming reduced detritivore facilitation of bacteria, decreasing decomposition and nitrogen flux.

Conclusions:

• Facilitative mechanisms between bacteria and detritivores in decomposition can collapse under warming.
• Detritivores support bacterial populations, aiding nutrient cycling, but warming mitigates these benefits.
• Warming impacts aquatic community structure and highlights the importance of interactive effects on freshwater ecosystems.