Rewilding for Fungi
Guest Blog by David Satori MSc
A Bit About Fungi
It’s no stretch to say that fungi have been overlooked in rewilding. What started as a way to explain and explore the effects of carnivores in shaping the landscape, evolved to cover broader aspects of the food web, including herbivores and even plants.
Fungi, on the other hand, are only just starting to make their way into the rewilding mainstream. They’re ephemeral organisms, with fruit bodies that crop up every autumn, or occasionally surprise us with an appearance after rainy weather, and they seem to live according to their own mysterious laws of nature. As such, it’s easy to assume that fungi are ever-present and we don’t really have to worry about them.
As we’ll see though, fungi are vital components of ecosystems, driving many natural processes upon which plants and animals depend, and we can’t always assume that current rewilding approaches will support important fungal communities. In Britain, we’re lucky enough to live in a hotspot for many groups of fungi, but at the same time they’re more threatened than plants or animals.
Rewilding holds perhaps the best chance of reversing their ongoing decline, and so I invite you to start thinking about how your own rewilding practices can support fungal conservation efforts. Before we dive into strategies, let’s start by dispelling a perennial myth about fungi.
The iconic Fly Agaric has spores that travel a surprisingly short distance on average
The Spore Dispersal Myth
Fungi have a reputation for being prodigious spore producers, and for good reason. A single Field Mushroom (Agaricus campestris) has been estimated to produce some 40 million spores per hour, and a bracket of Dryad’s Saddle (Cerioporus squamosus) can release up to 100 billion spores in a single growing season (Spooner & Roberts, 2005). Whilst some fungi solely rely on animal dispersal (think stinkhorns and truffles), we’ll limit our exploration to cap-and-stipe mushrooms for now.
In 1934, the microbiologist Lourens Baas Becking published a now-famous hypothesis that bears his name. He suggested that, when it comes to the distribution of microorganisms, everything is everywhere, and the environment selects. For fungi, this effectively means that if we have the right soil, or the right tree species, there are already specialist fungi lined up and waiting to grow.
We know that some fungal spores can reach phenomenal distances, but for most fungi, almost all spores fall within a couple of metres from their parent mushroom. Measuring the spore release of the iconic Fly Agaric (Amanita muscaria), one study found that only 5% of spores managed to reach a location 5.2 m away from the mushroom (source).
Unlike plant seeds, fungal spores aren’t able to grow into a ‘complete’ individual. They only contain half the genetic material needed, and so must also find a compatible mate which happens to germinate close to itself.
Copious spore production is the natural outcome of the sheer difficulty in reproducing as a fungus. Given that fungi are central to the establishment, succession, and resilience of ecosystems, this gives us some context for understanding why we need to explicitly consider fungi when rewilding. Let’s now look at some of the reasons why fungi are vital to nature recovery.
Fungi are Ecological Support Networks
The soil may mark our physical horizon, but it doesn’t have to be the limit of our rewilding horizon. Hiding in plain sight within soil and wood, fungi help create the conditions possible for woodlands, wood pastures, meadows, and even productive agricultural landscapes to function. Here are a just few examples of the ecological benefits that fungi provide:
Soil formation: dissolving rock, binding particles, increasing stability.
Soil fertility: decomposing organic matter, making nutrients available for plants, enhancing plant growth.
Ecosystem regulation: mediating plant-plant interactions, providing defence to plants against herbivory, food source for animals, regulating invertebrate populations – read more about this in ‘What are Mother Trees and Master Trees’.
Carbon sequestration: contributing a significant portion of the soil carbon pool.
Britain, a Fungal Biodiversity Hotspot?
I’m sure you’ve heard the news: Britain is considered one of the most nature-depleted nations on the planet.
It’s easy to get upset over the fact that so much wildlife has been lost from our landscapes and that our childhood baselines are a poor reflection of the biodiversity we would have had just 50 years ago. But Britain is a hotspot for fungi, and there are huge opportunities here for rewilders to bring back this missing biodiversity…
Britain lies at the intersection of many climatic gradients – the wetter west with its oceanic climate contrasts with the drier, continental conditions of the east. The warmer, temperate regions of the south are worlds apart from the semi-Boreal Scottish Highlands. It is this melting pot of climes that supports the diverse fungal communities we can find here – not just of barely-visible species that can only be appreciated with a microscope or a hand lens, I also mean big, colourful, and charismatic megafunga!
Read our first case study on Zoned Rosette – the fungus that looks more like a coral
Case Study 1
Zoned Rosette (Podoscypha multizonata)
This showy species looks more like something you’d find in a coral reef, and it’s certainly a far cry to call it a ‘mushroom’ in our usual sense of the word. Confined to the warmer southern counties of England, the Zoned Rosette grows at the base of old veteran oak trees in open woodlands, wood pastures, or parks where it feeds on underground roots. Despite being in decline across Europe and Asia due to habitat loss, it has a comfortable stronghold in none other than the parks of Greater London and its surrounding areas. It has been estimated that this hotspot, centred around our busiest city, hosts about 80% of the world’s population, and it appears to be quite stable here. The Zoned Rosette is not one you can easily misidentify, for its closest relatives grow in the tropics.
Whilst mainland Europe harbours more species of fungi in total, some of our most iconic British landscapes are home to concentrated assemblages of important fungi that are rare or declining elsewhere in the world. Here are just a few habitats where they can be found:
1. Ancient oak woodlands or wood pastures that support bulky-wood decomposer fungi, including the legally protected Bearded Tooth (Hericium erinaceus) and Oak Polypore (Piptoporus quercinus).
2. Old permanent grasslands that haven’t been fertilised or ploughed, which harbour colourful assemblages of waxcaps (Hygrocybe spp.), pinkgills (Entoloma spp.), earthtongues (Geoglossum spp., Trichoglossum spp.), fairy clubs, and coral fungi (Clavariaceae), many of which are on the brink of extinction in mainland Europe.
3. The Caledonian Forest of Scotland with its diverse group of ‘tooth’ fungi, where tiny hedgehog-like spines take the place of gills or pores, some oozing bright red droplets like the Devil’s Tooth (Hydnellum peckii – see pic above), and help Scots pine establish on gravelly, nutrient-poor soil.
4. Coastal sand dunes with their variety of earthstars (Geastrum spp. – see pic below), which are puffball-like fungi that grow out of the ground like onion bulbs before their outermost layer splits off into numerous ‘rays’ and expose a central spore-sac that makes them resemble cartoon stars or daisy flowers.
5. Atlantic temperate rainforest of western Britain, where important fungi grow not just in the soil, but over the moist branches of undisturbed trees, including the threatened Hazel Glove (Hypocreopsis rhododendri).
We often hear that fungi are one of the most diverse groups of organisms on the planet. We also hear of how resilient they can be in the face of environmental damage such as pollution. However, it’s crucial to remember that, like plants and animals, fungal diversity is vulnerable and many groups of species have seen stark declines in recent decades. In fact, DEFRA recently published a report to outline biodiversity targets, and concluded that fungi are the most threatened taxonomic group in the UK (Source).
To restore diverse, self-sustaining ecosystems, we need to consciously take into account all aspects of biodiversity, including fungi, otherwise rewilding itself may risk pushing species closer towards extinction.
Earthstars (Geastrum spp.) can be found on coastal sand dunes
When Reforestation is Bad for Fungal Conservation
As an avid rewilding enthusiast, it took me a long time to appreciate short-sward (highly-grazed) grasslands such as hill pastures. They resembled lawns too much, and appeared to be of low biodiversity value. The truth is, tightly-grazed grasslands would have been well represented in prehistoric Britain, when large herbivores roamed freely and maintained dynamic landscapes of open grasslands and scattered woods, perhaps not too dissimilar to what parts of New Forest look like today.
Many overgrazed pastures, among other grazed grassland types, are a hotspot for iconic waxcaps and their allies. So characteristic in fact, that they’ve been given their own name: ‘Waxcap grasslands’.
Waxcaps are a group of brightly coloured mushrooms with a characteristically waxy or slippery texture that grow in ‘unimproved’ grasslands (grasslands that haven’t been ploughed or fertilised in living memory) where nutrient levels are low and the long ecological continuity through time has kept underground fungal networks intact. We have about 50 species of waxcaps in the UK, and they often grow alongside other charming grassland fungi such as pinkgills, fairy clubs, and earthtongues.
Waxcap grasslands have seen widespread collapse across Europe as agricultural intensification increasingly made conditions inhospitable for these slow-growing fungi. In the UK, this decline has been surprisingly less drastic and we find those who manage livestock across extensive pastures to have been stewarding an internationally-significant biodiversity hotspot all along.
Case Study 2
Ballerina Waxcap (Porpolomopsis calyptriformis)
This pretty pink mushroom is one of the most iconic of our waxcaps, and can be found pirouetting on grass in all sorts of habitats, from pastures to lawns, and even graveyards. As it grows and absorbs water, its cap splits and curls upwards, resembling a flaring skirt. This dancer has faced considerable decline across Europe where it has been red-listed in 11 countries and is considered exceptionally rare. In Britain, particularly Wales, it is not an uncommon find, leading to it being removed from the British Red List after it was discovered how frequent it is!
Now more than ever, we’re seeing an upsurge of woodland creation projects, be they for biodiversity or for carbon offsetting, and it’s become quite a concern for waxcap conservation.
All too often, when offering up parcels of land to support woodland creation schemes, grasslands are evaluated largely against their value for wildflowers, birds, or pollinators, with virtually no input from mycological experts to balance the conversation. Interestingly, high fungal diversity isn’t often associated with high plant diversity, though both are excellent indicators of old, biodiverse habitats. As a holistic approach to nature recovery, rewilding is best placed to recognise the intrinsic value of these ancient fungal communities, especially when we have an international responsibility to uphold and protect them.
Unfortunately, we have a chronic shortage of mycologists among the ecological advisors contributing to conservation and nature recovery efforts. Without mycological input, our view of natural processes is incomplete and our range of solutions to restoring biodiverse ecosystems is diminished.
The author – mycologist David Satori – holding a specimen of Tooth Fungus (Sarcodon squamosus)
Rewilding with Fungi in Mind
By considering fungi within rewilding initiatives, we can expand our understanding of biodiversity and better-protect species of conservation concern, but every landscape is different, and each habitat calls for its own strategies. Below are some guidelines to help you get started.
If you have, or are creating, a woodland or wood pasture
To support beneficial mycorrhizal fungi, ensure a supply of suitable host trees of various age classes is present, maintaining a layer of seasonally short ground vegetation through managed grazing. Oftentimes, the complete exclusion of grazing animals from regenerating stands of trees leads to rank overgrowth of grasses and other herbaceous plants that discourages fungal fruiting.
If you have ancient or veteran trees on your site, you’ll likely notice various fungi that grow from the gnarled hollows, cavities and branches of the tree. Rare is the sight of an old oak without the vivid eruptions of the Beefsteak Fungus (Fistulina hepatica) or Chicken of the Woods (Laetiporus sulphureus – see pic below) at some point in the year, and these heart-rot fungi help lower the mass of old trees, making them more resilient against storm winds. Allowing these fungi to fulfil their ecological role not only benefits the tree, but can also create habitat for cavity-nesting birds, bats, rodents, ants, social bees, wasps, other fungi, and more.
If you have a grassland or a hay meadow
Perhaps the most important action to take when managing a grassland or a hay meadow is to do an autumn fungal survey to see if you can discover any waxcaps, earth tongues, fairy clubs or pinkgills. Grasslands are home to many types of fungi, including nitrogen-loving species that often grow on herbivore dung, rusts that grow on herbaceous plants, and soil-dwelling species that grow in fairy rings. Any rewilding sites should be evaluated based on their proximity to remnant waxcap grasslands to gauge their value.
If you have a garden
From landscape-scale restoration down to the smallest urban gardens, there is something beneficial that can be done for fungal wildlife. Much like wood piles and fallen logs can be safe havens for various beetles, so too can they support decomposer fungi that in turn soften wood and help feed invertebrates. Surprisingly, lawns can also be refuges for grassland fungi such as waxcaps, though these can take many decades to create and depend on successful dispersal from nearby locations. Old, mossy lawns with waxcaps can be taken care of through seasonal mowing to create a short sward in the autumn, and it goes without saying that avoiding the use of fertilisers, herbicides, and pesticides will support the recovery of more fungal wildlife too.
This Laetiporus sulphureus is typically known as ‘Chicken of the Woods’ after its taste
As we’ve seen, fungi drive many irreplaceable processes in nature, and it’s in our best interests to know how these processes occur so that we can make better land management decisions. You may have also noticed that, from a mycological standpoint, traditional farming practices and fungal conservation aren’t necessarily antagonistic either, and neither does rewilding have to be.
Whilst this article is only a starting point for helping you rewild with fungi in mind, I hope you’re as excited as I am to see what the future of rewilding has in store for protecting and restoring these fascinating and important organisms.
Lose Yourself in a Rewilded World
Department for Environment, Food and Rural Affairs (DEFRA), 2022. Biodiversity Terrestrial and Freshwater Targets. Detailed Evidence report. p. 118.
Li, D., 2005. Release and dispersal of basidiospores from Amanita muscaria var. alba and their infiltration into a residence. Mycological research, 109(11), pp.1235-1242.
Spooner, B.M. and Roberts, P., 2005. Fungi. Harper UK.
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