Threatened Biodiversity: How Fungi Fall Victim to Climate Change and Deforestation

The silent crisis beneath our feet: A recent assessment by the International Union for Conservation of Nature (IUCN) shows that nearly a third of all studied fungal species are threatened with extinction. The main drivers are global deforestation and fungi climate change, which fundamentally alters the delicate habitats of these organisms. For mushroom foragers and nature enthusiasts, this means that the species we still find on our forest walks today could become rare within just a few decades.

The Invisible Threat: Fungi and Climate Change in the Research Spotlight

The Earth is home to an estimated 2.2 to 3.8 million fungal species – yet only a fraction have been scientifically described. A study published by the IUCN in March 2024 has now, for the first time, subjected a representative cross-section of over 1,300 fungal species to a systematic risk analysis. The result is alarming: around 30 percent of the studied species are considered threatened, endangered, or potentially endangered. Particularly affected are mycorrhizal fungi, which live in symbiosis with tree roots. They depend on intact forest ecosystems – and these are rapidly disappearing due to deforestation and the effects of fungi climate change.

The study, published by Earth.Org, shows that the greatest risks come from habitat destruction. In tropical regions, where deforestation rates are highest, up to 40 percent of the local fungal flora is threatened. At the same time, in temperate latitudes, rising temperatures are shifting the distribution ranges of many species northward or to higher elevations. Anyone who regularly uses the FungiFind Mushroom Map knows the phenomenon: species that previously only occurred in southern Germany are suddenly appearing in northern Germany – while classic companions of spruce forests are becoming rarer.

How Climate Change Affects Fungal Growth

The impacts of fungi climate change are diverse and affect nearly all life stages of a fungus. Phenology – the timing of fruiting body appearance – is changing dramatically. Spring and autumn mushrooms now appear on average two to three weeks earlier than 50 years ago. At the same time, longer dry periods in summer mean that many species do not form fruiting bodies at all. Heavy rainfall events, in turn, can damage mycelia and disrupt nutrient uptake.

The situation is particularly critical for mycorrhizal fungi, which depend on carbohydrates from their tree partners. During dry periods, trees reduce their photosynthetic activity and provide less sugar for the fungi. The weakened mycelium can then barely supply nutrients and water to the tree – a vicious cycle that weakens both partners. The FungiFind Blog has already reported on such interactions multiple times. The new IUCN study now confirms: these processes are not local phenomena but global threats.

Forest Soils as Carbon Sinks at Risk

An often overlooked aspect is the role of fungi in the global carbon cycle. Fungi are the most important decomposers of organic matter and store enormous amounts of carbon in the soil. Mycorrhizal networks transport up to 15 percent of the carbon bound by trees into the soil. When these networks collapse due to drought or deforestation, the stored carbon is released – a dangerous feedback loop that further accelerates climate change.

The IUCN study emphasizes that protecting fungal diversity is urgent not only for species conservation but also for climate stability. Forests with intact fungal communities demonstrably store more carbon than disturbed ecosystems. In this context, apps like FungiFind are gaining importance: they not only help with identification but also document locations and frequencies. This way, users can actively contribute to monitoring biodiversity. For example, anyone who finds a Common Ink Cap can report via the app whether it is in an area with high or low drought stress – valuable data for research.

What Does This Mean for Mushroom Foragers?

The study's results are a wake-up call, but no reason to panic. Many common edible mushrooms like porcini or chanterelles are not yet acutely threatened – though they are already showing declines in particularly dry regions. Those who want to continue foraging successfully should stay informed about seasonal shifts. The FungiFind Species Encyclopedia provides up-to-date data on occurrences and optimal harvesting times. Importantly: do not collect mushrooms from overused or damaged stands, and be considerate of rare species.

But the study also makes clear: protecting fungi means protecting forests. Anyone who advocates for the preservation of old forests, nature-friendly forestry, and the fight against climate change automatically helps fungi. Every walk in the forest, every report of a find in the FungiFind app, and every conversation about the importance of fungi helps raise awareness for this invisible but vital form of life.

Note: This article is for informational purposes and does not replace professional mushroom advice. If you are unsure about identification or edibility of mushrooms, please contact a local mushroom advisory service.

Conclusion: Act Before It's Too Late

The news that nearly a third of studied fungal species are threatened with extinction is an alarm signal. Fungi climate change and deforestation are severely impacting one of the oldest and most important groups of organisms on Earth. But there is hope: through targeted conservation measures, sustainable forest management, and support for citizen science projects like FungiFind, we can reverse the trend. Every find counts – and every report helps improve the data foundation on which political decisions can be based.