Positive Feedback on Climate Warming by Stream Microbial Decomposers Indicated by a Global Space-For-Time...

Area of Science:

• Ecology
• Biogeochemistry
• Climate Science

Background:

• Stream decomposition is vital for the global carbon cycle, yet its temperature sensitivity is not fully understood.
• Understanding how temperature affects decomposition is crucial for predicting climate change impacts.

Purpose of the Study:

• To investigate the mechanisms of temperature sensitivity in stream plant litter decomposition.
• To forecast the effects of climate warming on decomposition processes in streams.

Main Methods:

• Compared microbial and total decomposition rates across 41 global sites using nine plant species in six mixtures.
• Assessed temperature sensitivity (TS) of decomposition.

Main Results:

• Microbial decomposition followed metabolic theory, showing higher TS than total decomposition.
• Total decomposition's TS was higher than previously reported and varied with litter recalcitrance.
• Warming is projected to increase the microbial decomposition contribution.

Conclusions:

• Climate warming will enhance microbial decomposition, increasing CO2 outgassing and amplifying warming, particularly in colder regions.
• Riparian plant species composition significantly influences decomposition rates and temperature sensitivity.