WOODLAND AND HEDGEROW - TREES AND FUNGI

Different types of woodland attract people in different ways and some are certainly more appealing visually than others. Unfortunately, some of the most attractive are not necessarily the best for wildlife, in particular the monocultures that are Beech woods. In the number of species supported, they simply cannot compare with mixed woods, or Oak woodland, and in some ways a decaying or fallen Beech is better news than one at the height of its powers. That much may be evident on the following page, which deals with dead wood.

Each type of woodland has its share of fungi, whose visible aspect is, in many ways, the least significant part of their valuable activity. Fungi do not have a great image overall, in so far as they tend to be associated in the popular mind with such elements as poison, rotting and hallucination. As often as not, the spore-bearing fruits are knocked over by people as soon as they appear. In an era when recycling has become trendy, albeit still insufficiently focussed, this mindset about fungi really should be reassessed.

To all intents and purposes, every living creature in a woodland ecosystem depends on fungi, which lack chlorophyll and have to obtain nutrients from other sources, namely decaying organic matter of all kinds or living organisms.

Their work in breaking these down and releasing nutrients maintains the fertility and productivity of the woodland, and symbiotic fungi assist trees in such areas as the supply of water and stability of the root system, which fungi can extend and protect by covering.

The scale is unimaginable from the surface, given that the subterranean thread-like mycelia (ectomycorrhiza) of some species are the largest living organisms in Britain based on area covered. The fruiting bodies are the end of the story in one sense, but the beginning of another as millions of spores are distributed.

Regrettably, though large and in some respects tough, mycelia are in fact fragile and subject to ill-effects from pollution and, with warmer summers, drying out. The possible consequences to our woodland and environment in general of a serious decline are unimaginable.

Many fungi – there are more than 3,000 different types in the UK – are generalists, found in a number of different types of woodland, but others are more specific.

Birch (Betula pendula) woodland, for instance, has an obvious specialist in Birch Polypore (Piptoporus betulinus), which is found on living and decayed trees from summer to autumn and sometimes remains with edges fraying for much longer. muscaria), poisonous and a strong hallucinogen, is associated more with Birch than any other tree in Britain.

In Beech (Fagus sylvatica) woodland, Porcelain Fungus (Oudemansiella mucida) is specific to the Beech, sometimes appearing in large clusters from September to November. Like so many fungi, it provides nourishment to slugs. Pseudotrametes gibbosa is commonly also found on Beech, though the tree needs to be dead or decaying. This fungus can last for quite a while, with not even frosts causing immediate disintegration.

In Oak (Quercus sp) woodland, the Beefsteak fungus (Fistulina hepatica) is a specialist which soon darkens and goes slimy before rotting, but the darker colouration it gives to infected wood makes it valuable for the furniture industry.

In contrast, a fungus that is unpopular with commercial foresters because it attacks conifers – which in the south ought to make it a friend of environmentalists – is the striking parasite Phaeolus schweinitzii, with its remarkable ‘organ’ shape.

Stinkhorn (Phallus impudicus) is associated with rotting wood in almost any location. The fruit starts off egg-shaped and the full fungus bursts through overnight, attracting flies in hundreds to the foul-smelling slime on the head. The flies disperse the spores and the Stinkhorn soon collapses.

Dog Stinkhorn (Mutinus caninus) is somewhat slighter than Stinkhorn but follows the same process and is usually found near decayed deciduous wood. Another generalist in the type of tree it lives on is Dryad’s Saddle (Polyporus squamosus), an impressive fungus found from spring to autumn on stumps or living trunks, sometimes in wounds, of Ash (Fraxinus excelsior), Beech and Maple (Acer sp) among others. Boletus versicolor is one of 36 Boletus fungi in Britain, which are chunky or even bloated in some instances, with a definite cap. Virtually all emerge from the ground near broad-leaved trees. Boletus versicolor is quite rare.

Jew’s Ear fungus (Auricularia auricula-judae) is much commoner though fairly specific in its requirements, being found for much of the year on the branches of Elder trees (Sambucus nigra) where it can form bulk growth. It is one of the so-called jelly fungi though the texture is much more rubbery than jelly-like. On occasions, as in the image above, the fungus can have a slightly eery appearance.

Tremella foliacea is another jelly fungus and this one does have more of the look and feel of the substance after which it is named. The species is found growing on trees or stumps, often in nutrient poor soil. That habitat also suits the Butter Cap (Collybia butyracea), or Greasy Tough-shank, which is seen in leaf litter in autumn and early winter, and the Parasol mushroom (Lepiota procera). The latter tastes excellent and is less common than the related Shaggy Parasol (Lepiota rhacodes). Open woodland and grassland are among its main habitats.

As mentioned above, Pseudotrametes gibbosa specialises on dead or decaying wood and plenty of other fungi follow suit. Two found mainly on trees that grew in rich soil are Scarlet Elf Cup (Sarcoscypha coccinea) and Velvet Shank (Flammulina velutipes). The former, with its stunning colouring and pleasing shape, develops in long-fallen branches that are half-buried. Frequently these are from Alder (Alnus glutinosa) or Willow (Salix sp), and Scarlet Elf Cup is one of the earliest fungi to appear in the new year, with the months February to April favoured.

Velvet Shank grows in striking clusters on stumps and fallen branches. The virtual disappearance of Elm (Ulmus procera) through Dutch Elm Disease in the 1970s removed the tree which seemingly best suited this fungus, but it is still common, using such as Alder, Elder and Ash.

Hairy Stereum (Hereum hirsutum) is one of the commonest of all fungi on piles of logs but is also located on virtually any dead deciduous wood. Brick Caps (Hypholoma sublateritium) appear in sizeable bunches on deciduous stumps in the autumn but they are less common than Velvet Shank for one. The pictured group suffered the familiar fate for fungi outlined above, in so far as all the fruits were systematically kicked down by someone the day after I took the photograph.

For the record, some of the English names of fungi are certainly sinister or other-worldly. Not that this, together with the small proportion which are poisonous, justifies the number of casual thumpings dished out to fruits. The names include Death Cap, Dead Man’s Fingers, Witches’ Bonnet, Weeping Widow and Destroying Angel.

Given suitable conditions – they are among the most reliable indicators of air pollution levels – Lichen are not only powerful but long-living combinations of fungi and algae. The fungus, called the mycobiont, rules the alga, or phycobiont, and they reproduce either vegetatively or sexually. The alga contains chlorophyll and can photosynthesise, providing the lichen with carbohydrates to develop.

With its brilliant red heads containing spores atop relatively dull stems Cladonia floerkana is one of the most striking lichens. It is found fairly easily on rotting wood (you can hardly miss it), mainly in acidic areas, particularly with soil consisting of peat or sand.

Images © Jeremy Early. All rights reserved.

In 2013 I published My Side of the Fence - the Natural History of a Surrey Garden. Details may be found, and orders placed, via this hyperlink My Side of the Fence. In November 2015 Surrey Wildlife Trust published the atlas Soldierflies, their allies and Conopidae of Surrey, jointly written by David Baldock and me. Details are on this web page: Atlas.