Host Developmental Stage and Vegetation Type Govern Root EcM Fungal Assembly in Temperate Forests

Area of Science:

• Ecology
• Mycology
• Forest Science

Background:

• Ectomycorrhizal (EcM) fungi are crucial for forest succession, but the roles of neutral and niche-based processes in their community assembly remain unclear.
• Understanding these assembly processes is vital for predicting forest dynamics and ecosystem functions.

Purpose of the Study:

• To investigate the assembly processes of EcM fungal communities in juvenile and adult coniferous and broadleaf trees in northeastern China.
• To determine the relative contributions of stochastic and deterministic processes in shaping EcM fungal communities across different host tree ages and species.

Main Methods:

• Neutral theory modeling to assess stochastic processes.
• Alpha and beta diversity metrics to quantify community composition.
• Random forest analysis to identify key drivers of community structure.
• PERMANOVA to test the effects of host age and identity.

Main Results:

• Neutral processes explained more variation in adult trees (over 33%) than juvenile trees (under 7%), indicating a successional shift in assembly mechanisms.
• Alpha diversity increased with host age, while beta diversity was more influenced by host age than host identity.
• Distinct EcM fungal taxa were associated with juvenile vs. adult and coniferous vs. broadleaf hosts.

Conclusions:

• Host tree maturity is a key driver transitioning EcM fungal communities from deterministic to stochastic assembly.
• Tree species identity modulates these assembly processes, impacting plant-fungal dynamics during forest succession.
• Findings enhance the understanding of forest ecosystem development and the role of symbiotic fungi.