Global ecological predictors of the soil priming effect

Area of Science:

• Soil Science
• Ecology
• Biogeochemistry

Background:

• Understanding soil priming is crucial for modeling terrestrial carbon (C) cycling.
• Soil priming describes the change in soil organic matter decomposition due to the addition of fresh organic matter.

Purpose of the Study:

• To identify the global drivers of apparent soil priming effects.
• To investigate the relationship between soil properties and the soil priming effect.

Main Methods:

• Surveyed soils from 86 globally distributed locations.
• Utilized 13C-glucose labeling to measure apparent soil priming effects.
• Employed statistical modeling to analyze relationships between priming and environmental factors.

Main Results:

• Positive apparent priming effects (increased CO2 release) were negatively associated with soil organic carbon (SOC) content and microbial respiration.
• Apparent priming effects were generally negative in mesic sites with high SOC content.
• Positive apparent priming effects were observed in arid sites with low SOC content after labile carbon addition.

Conclusions:

• Soil organic carbon content is a critical regulator of apparent soil priming effects globally.
• Findings have significant implications for refining carbon cycling models under changing global conditions.
• The study highlights the context-dependency of soil priming, influenced by climate and soil properties.