Global patterns and drivers of initial plant litter ash concentration

Area of Science:

• Ecology
• Biogeochemistry
• Plant Science

Background:

• Plant litter ash is crucial for decomposition and nutrient cycling.
• Global patterns and drivers of initial litter ash concentration are not well understood.

Purpose of the Study:

• To assess global patterns of initial plant litter ash concentrations.
• To evaluate the influence of mycorrhizal association, plant traits, and environmental factors on ash concentration.
• To elucidate the mechanisms driving ash concentration in different plant tissues.

Main Methods:

• Compiled data from 570 observations across 104 publications.
• Analyzed variations in ash concentration across plant tissues (leaf, root, bark, etc.).
• Investigated the effects of arbuscular mycorrhiza (AM) vs. ectomycorrhiza (ECM), taxon group, life form, leaf type, climate, and soil properties.

Main Results:

• Global average ash concentrations differed significantly by plant tissue, with leaf litter highest (7.3%) and wood litter lowest (1.5%).
• Leaf litter ash was higher in AM plants and angiosperms/broadleaf species; root litter ash varied with mycorrhizal association and was higher in angiosperms.
• Mycorrhizal association and taxon group primarily drove leaf litter ash, while root litter ash was influenced by mycorrhizal association and soil organic carbon.

Conclusions:

• Initial plant litter ash concentration exhibits significant global variation driven by plant traits and environmental factors.
• Understanding these patterns is key to predicting litter decomposition rates and nutrient cycling dynamics.
• Mycorrhizal associations play a critical role in modulating ash content and subsequent ecosystem processes.