Leaf litter decay rates differ between mycorrhizal groups in temperate, but not tropical, forests

Area of Science:

• Ecology
• Forest Science
• Mycology

Background:

• Litter decomposition is crucial for ecosystem nutrient cycling.
• Predicting interspecific variation in litter decay remains challenging.
• Tree mycorrhizal associations influence soil carbon and nutrient dynamics.

Purpose of the Study:

• To test if arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) fungi influence litter decomposition rates.
• To develop a predictive framework for litter decay based on tree mycorrhizal type.

Main Methods:

• Compiled leaf litter chemistry and decay data for over 200 angiosperm and gymnosperm species.
• Analyzed data from temperate, tropical, and subtropical forests.
• Investigated relationships between decay rates, mycorrhizal association, phylogeny, and climate.

Main Results:

• In temperate forests, AM litters decomposed significantly faster than ECM litters.
• Litter nitrogen and plant phylogeny were key predictors of decay in temperate forests.
• No significant difference in decomposition rates was observed between AM and ECM litters in subtropical/tropical forests, where phosphorus was the main driver.

Conclusions:

• Tree mycorrhizal association is a significant factor influencing litter decomposition, especially in temperate forests.
• Incorporating mycorrhizal type into models can improve predictions of species' effects on ecosystem processes.
• This research provides a framework linking litter quality, tree symbionts, and nutrient acquisition.