Different twig litter (Salix caprea) diameter does affect microbial community activity and composition but not decay...

Area of Science:

• Forest ecology
• Soil science
• Microbial ecology

Background:

• Small twigs are a significant source of organic carbon in forest soils.
• Factors influencing twig decomposition, particularly twig size, are not well understood.

Purpose of the Study:

• To investigate the effect of twig size on decomposition rates.
• To examine how twig size influences the composition and activity of soil microbial communities during decomposition.

Main Methods:

• Litterbags containing twigs (Salix caprea) of two different diameters were placed in the forest litter layer.
• Samples were collected over a seven-year period to measure mass loss and microbial parameters.
• Microbial community composition and activity were analyzed using various measures.

Main Results:

• Microbial colonization was faster on thin twigs, with a higher proportion of bacteria.
• Thick twigs exhibited a more gradual microbial community development with a higher proportion of fungi.
• Despite differences in microbial succession, no significant difference in mass loss was observed between twig diameters after seven years.

Conclusions:

• Twig size affects microbial community succession, favoring bacteria on smaller twigs and fungi on larger ones.
• Surface-to-volume ratio, while influencing microbial succession, may not be a primary predictor of long-term twig decomposition rates.
• Forest soil organic carbon input via twigs is substantial, but decomposition is less dependent on size than initially hypothesized.