Competition-function tradeoffs in ectomycorrhizal fungi

Area of Science:

• Ecology
• Mycology
• Forest Science

Background:

• Ectomycorrhizal fungi community composition influences ecosystem functions like primary production and carbon storage.
• Factors governing ectomycorrhizal fungal community structure at the root system scale are not fully understood.
• A potential tradeoff between fungal competitive ability and enzymatic function is explored.

Purpose of the Study:

• To investigate the relationship between ectomycorrhizal fungal competitiveness and extracellular enzyme activity.
• To understand how fungal traits influence community composition in terrestrial ecosystems.

Main Methods:

• Pinus muricata seedlings were grown with three different ectomycorrhizal fungal genera.
• Seedling growth, ectomycorrhizal colonization, and root tip enzyme activity were measured.
• Activity of five extracellular enzymes involved in carbon and phosphorus mobilization was assessed.

Main Results:

• An inverse relationship was observed between fungal competitiveness and enzymatic activity.
• The dominant fungus, Thelephora terrestris, exhibited the lowest enzyme activity.
• The least dominant fungus, Suillus pungens, demonstrated the highest enzyme activity.

Conclusions:

• A tradeoff exists between ectomycorrhizal fungal competitive ability and enzymatic function.
• This tradeoff may be linked to the energetic costs of competition versus enzyme production.
• Host tree mechanisms for maintaining beneficial fungal partners are crucial for ecosystem health.