Deciphering the Complex Interactions between Litter Inputs and Microbial Responses in Modulating Long-Term Soil...

Area of Science:

• Forest ecology
• Soil science
• Microbial ecology

Background:

• Forests are crucial for natural climate solutions, with soil organic matter (SOM) playing a key role in carbon sequestration.
• The microbial regulation of carbon cycling in temperate forest soils is complex and uncertain, especially under increased litter inputs.

Purpose of the Study:

• To investigate the long-term effects of chronic litter addition on SOM composition and microbial communities in a temperate deciduous forest.
• To determine if increased litterfall enhances carbon sequestration or leads to soil carbon loss.

Main Methods:

• Analysis of SOM composition using molecular-level evidence.
• Characterization of microbial community structure and function.
• Experimental manipulation of detrital inputs over a 30-year period.

Main Results:

• Chronic litter addition over 30 years did not increase soil carbon stocks.
• Litter addition led to shifts in microbial community composition and altered carbon utilization strategies.
• Excluding litter inputs resulted in decreased soil carbon content and enhanced SOM decomposition by specific bacterial groups.

Conclusions:

• In mesic temperate forests, increased litterfall does not necessarily lead to enhanced carbon sequestration.
• Microbial community shifts and altered carbon use strategies can counteract potential carbon gains from increased litter inputs.
• Forest management strategies aimed at increasing carbon sequestration must consider microbial responses and soil carbon dynamics.