Plant and mycorrhizal fungal diversity hotspots

Plant hotspots don’t reveal fungal hotspots, conserving one doesn’t guarantee protecting the other.

Plants and fungi don’t always share the same biodiversity hotspots. While plant diversity peaks in tropical forests, fungal diversity is highest in grasslands and cooler forests. This mismatch means conservation plans focused only on plants risk leaving out much of the critical fungal diversity that supports healthy ecosystems.

This study looks at whether the world’s most plant-rich places are also rich in fungi that live in partnership with plants (mycorrhizal fungi). These fungi are vital for helping plants get nutrients and for keeping ecosystems healthy.

We compared global maps of plant diversity with maps of two major groups of mycorrhizal fungi:

Arbuscular mycorrhizal (AM) fungi, which partner with most plants.

Ectomycorrhizal (ECM) fungi, which partner with specific trees like pines and oaks.

We found that plant and fungal diversity hotspots rarely overlap. For example:

Plant diversity peaks in tropical forests (like the Amazon and Southeast Asia).

AM fungi also peak in some tropical grasslands and savannas.

ECM fungi are most diverse in cooler temperate and boreal forests (like parts of North America, Europe, and Asia).

In fact, less than 9% of AM hotspots and only 1.5% of ECM hotspots overlap with plant hotspots.

This means that protecting areas based only on plant diversity risks ignoring critical belowground fungal diversity. The study shows that conservation needs to include both plants and fungi if we want to safeguard ecosystems and their resilience to global change.

Our key finding is a global mismatch: areas richest in plant diversity (e.g., tropical rainforests) do not align with those of mycorrhizal fungi, which peak in temperate regions, grasslands, and drylands. This divergence suggests that plant and fungal diversity are shaped by distinct evolutionary and environmental drivers.

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