Why Some Trees Fall in Storms and Others Survive: The Role of Spalting 2026

Why do some trees fall in storms while others stand firm? The answer often lies hidden within the wood itself, in a process called spalting and the relentless work of fungi. In a Norfolk woodland, an ash tree with ash dieback swayed and groaned, its split trunk opening and closing like a mouth, yet it survived two storms that felled sycamores, other ashes, and an oak. The key difference? The fallen ash was hollow, its cavity teeming with golden scalycap and honey fungus, whose black rhizomorphs—bootlace-like tendrils—had rotted the roots and weakened the trunk. This story reveals how decay, disease, and fungal competition determine which trees withstand gales and which succumb.

What Is Spalting and How Does It Weaken Trees?

Spalting is a condition in which fungi colonize wood, causing discoloration and decay. The fungi that cause spalting can break down lignin and cellulose, the structural components of wood, leading to internal cavities and reduced strength. In the case of the fallen ash, the hollow trunk and the presence of honey fungus (bootlace fungus) indicate advanced decay. The black rhizomorphs of honey fungus spread underground from tree to tree, seeking roots to infect. Once inside, the fungus grows beneath the bark, rotting the wood and slowly killing the tree. When storms hit, these weakened trees are the first to topple.

Why Did the Ash with Ash Dieback Survive?

The ash with ash dieback, despite its audible groaning and split trunk, did not fall. This may seem counterintuitive, but its survival could be due to several factors. First, the tree might have had a more extensive root system or a trunk that, while damaged, retained enough sound wood to withstand the wind. Second, the split trunk may have allowed the tree to flex rather than snap. Third, the presence of ash dieback does not necessarily mean the wood is hollow or decayed; the disease primarily affects the foliage and branches, and the trunk may remain structurally sound for years. In contrast, the fallen ash was completely hollow, its structural integrity compromised by fungal rot.

The Role of Fungal Competition in Tree Decay

When two different fungi colonize the same piece of wood, they compete for territory. Each fungus establishes a boundary, sealing off its patch with darkly pigmented fungal threads, a phenomenon known as spalting. This competition can actually slow decay in some cases, as fungi expend energy fighting each other rather than breaking down wood. However, the overall effect is still a weakening of the tree. In the fallen ash, the presence of both golden scalycap and honey fungus suggests a complex battle for resources, ultimately leaving the wood brittle and prone to failure.

What This Means for Woodland Management

Understanding why trees fall is crucial for woodland management, especially as storms become more frequent with climate change. Foresters and landowners can use this knowledge to identify hazardous trees and manage them proactively. Regular inspections for signs of fungal infection, such as rhizomorphs, fruiting bodies, and hollow trunks, can help prevent accidents and preserve woodland health. Moreover, promoting biodiversity in woodlands can encourage a balance of fungi and other organisms that may reduce the spread of aggressive pathogens like honey fungus.

Key Takeaways

• Spalting and fungal decay are major causes of tree failure in storms.
• Honey fungus spreads via black rhizomorphs and rots roots, weakening trees.
• Ash dieback alone doesn't necessarily make a tree more likely to fall.
• Fungal competition can slow decay but still compromises wood strength.
• Regular woodland inspections help identify hazardous trees.

Comparing Tree Conditions and Storm Outcomes

The drama of the woodland—trees swaying, groaning, and falling—offers a window into the hidden world of fungi and decay. For those who spend time in nature, these observations deepen our appreciation of forest ecology. If you're fascinated by such natural stories, you might enjoy reading about how rain transforms drought-stricken land, a country diary that captures the resilience of nature. Similarly, the Guardian Country Diary's 1,000th article celebrates milestones in nature writing, reminding us of the importance of documenting these changes.

As storms become more frequent, understanding tree survival is more important than ever. The Country Diary on beech trees and summer heatwaves shows how climate stress affects woodlands. Another entry, marking the 1,000th article with thanks, highlights the gratitude we owe to those who observe and record nature's shifts.

Wildlife often bears the brunt of these changes. The Country Diary on hares in wheat stubble offers a glimpse of how animals adapt to altered landscapes. Meanwhile, moorland rain bringing relief illustrates the regenerative power of weather. These stories remind us that every storm leaves a mark, but also brings renewal.

Finally, the intricate relationships in nature are beautifully captured in a country diary where a small stone bridge becomes a stage, and in tales of butterflies, battle re-enactments, and ancient oaks. These observations enrich our understanding of the natural world and its constant state of change.