Functionally dissimilar neighbors accelerate litter decomposition in two grass species

Area of Science:

• Ecology
• Plant-soil interactions
• Ecosystem functioning

Background:

• Plant litter decomposition is crucial for nutrient cycling.
• Litter decomposition depends on litter quality and decomposer efficiency.
• Neighboring plant traits can modify these factors, but their impact on focal litter decomposition is unclear.

Purpose of the Study:

• To investigate how functional-trait dissimilarity to neighboring plants affects the decomposition of a focal plant's litter.
• To understand the role of plant-plant interactions in modifying litter quality and decomposer efficiency.

Main Methods:

• Experimental mesocosms cultivated with two grass species (Brachypodium pinnatum and Elytrigia repens).
• Reciprocal litter transplantation between functionally similar and dissimilar neighborhoods.
• Analysis of litter quality and decomposer efficiency.

Main Results:

• Litter quality increased in functionally dissimilar neighborhoods for both species.
• Changes in functional traits involved in plant-plant interactions contributed to improved litter quality.
• Functional dissimilarity enhanced decomposer efficiency in one species, likely due to complementarity effects.

Conclusions:

• Interspecific functional diversity in plant communities enhances intraspecific litter decomposition.
• Plant species may perform better in diverse communities due to increased remineralization rates of their own litter.
• This highlights a novel mechanism of biodiversity effects on grassland ecosystem functioning.