Fungi: The Hidden Allies in Forest Restoration

In the quiet, ancient woodland of Ballachuan Hazelwood in Scotland’s Hebridean islands, lie relations deeper and more ancient than any human history, mycorrhizal fungal networks that connect the roots of hazel trees across landscapes. These “magic mushrooms,” as the Guardian piece aptly describes, are now emerging as critical players in rewilding and forest recovery, offering a new frontier in restoring degraded ecosystems.

Mapping the Underground “Circulatory System”

Led by the Society for the Protection of Underground Networks (SPUN), biologists such as Bethan Manley and David Satori are challenging our traditional view of reforestation. Instead of focusing solely on planting trees, their work reveals just how essential soil fungi are to forest recovery. At Ballachuan, and across sites ranging from Colombia’s rainforest valleys to Palmyra Atoll, SPUN is mapping these mycorrhizal networks, often described as the planet’s circulatory system.

This quest involves sampling soil and environmental DNA at over 20 locations to establish the first global atlas of these fungal communities. It’s a groundbreaking initiative: three-quarters of fungi are known only by their DNA, never observed directly. Yet this hidden biodiversity is pivotal, adding healthy native fungal communities to degraded forests can boost plant growth by up to 64%.

The UK’s Chance to Lead a Rainforest Revival

Temperate rainforests, though rare, still cling on in parts of the UK. These fragile ecosystems cover less than 1% of global forested land, yet two-thirds of them are under threat from changing weather patterns. With vast stretches of rainy untapped land, Britain and Ireland have a unique opportunity to take global leadership in their restoration. The ancient hazelwood trees in Scotland, dating back millennia, represent living testaments to what could be regained.

But for new forests to take root and thrive, fungal partners must be reintroduced. In places where forests have been absent for centuries, the soil often lacks the mycorrhizal network needed to support seedlings struggling against drought and poor nutrient conditions.

Practical Paths to Reconnection

Restoration efforts are already incorporating techniques that recognize these underground alliances:

• At Totnes’s Bowden Pillars, soil from intact rainforest was used to inoculate planted seedlings, encouraging natural fungal growth alongside new saplings.

• The National Trust in Devon is exploring similar methods, including smaller-scale fungal inoculation to revive local soil health.

Creating fungal refugia, preserved forest fragments rich in underground networks, could serve as sources of restoration for multiple fragmented landscapes. Over time, reconnection of these zones would allow not just fungi, but also insects, animals, and plants, to reclaim their roles in resilient ecosystems.

Why This Matters for Conservation

We often hear that plants are key to absorbing carbon and restoring ecosystems, but fungi are just as vital. These subterranean networks store vast amounts of carbon, prevent soil degradation, and help forests adapt to changing conditions. Yet, they remain largely invisible, ignored by environmental policies and neglected in land management strategies.

The work of SPUN, and similar initiatives, is changing that. Mapping fungal biodiversity and incorporating it into restoration plans offers a far more holistic view of ecosystem conservation. By rethinking forests as communities that include soil fungi, we pave the way for regeneration that’s deeper, more resilient, and fully alive.