Plant-soil feedbacks and mycorrhizal type influence temperate forest population dynamics

Area of Science:

• Ecology
• Forest Science
• Mycology

Background:

• Plant-soil feedback is crucial for terrestrial plant diversity.
• Factors regulating plant-soil feedback, which varies from positive to negative, are not fully understood.

Purpose of the Study:

• To investigate the role of mycorrhizal association type in regulating plant-soil feedbacks in North American trees.
• To determine how mycorrhizal type influences population regulation and community structure.

Main Methods:

• Conducted a large-scale study across 550 populations of 55 North American tree species.
• Analyzed plant-soil feedbacks in soil collected beneath conspecifics.
• Compared feedback responses between arbuscular mycorrhizal and ectomycorrhizal trees.

Main Results:

• Mycorrhizal association type explained significant variation in plant-soil feedbacks.
• Arbuscular mycorrhizal trees experienced negative feedback, while ectomycorrhizal trees showed positive feedback.
• Arbuscular mycorrhizal trees had strong conspecific inhibition across scales; ectomycorrhizal trees showed local facilitation and regional inhibition.

Conclusions:

• Mycorrhizal type is a key factor shaping plant-soil feedbacks.
• These feedbacks, influenced by mycorrhizal type, play a significant role in regulating tree populations and community structure in temperate forests.