Autumn reflections

Field Notes

3 Nov

In this issue of Field Notes, Volunteer Liz Andrew writes about the fungi she’s discovered when out and about on Hampstead Heath.

The butterflies have gone, the last few dragonflies are hanging on at Wood Pond, and there are only a few wild flowers in isolated pockets in the woods and meadows. But the colours on the Heath are spectacular, in greens, golds and reds as the leaves start to break down their pigments to store for future use. Chlorophyll, the green sunlight-catching pigment, is usually the first to break down, sometimes leaving the red or yellow pigments that result in the glorious colours we’re seeing this autumn

Scrunching through a sea of golden fallen leaves under the beech trees with the sun casting long shadows almost compensates for the prospect of long nights and colder, wetter weather to come. As it’s officially autumn, I’ve turned my attention to walking in the woods, peering into the brambles, scanning the dead logs or looking up at the dead trees, trying to find fungi. They’re fairly easy to spot and some of them are easy to identify, but most just look like tiny mushrooms or a funny scaly patch or blob of jelly on a dead branch. My Guide to Fungi book isn’t all that helpful, but I was very lucky a couple of weekends ago to go out with a couple of expert mycologists – people who specialize in identifying everything from a toadstool to a bracket to an earthball and more. We found over 70 species in the space of about four hours. How was I going to remember them all? The short answer was not easily and probably not at all. The experts tended to use the Latin names, but as many of the ones we spotted had common names as well that made it a bit easier. We found Bonnets and Milkcaps, Toughshanks and Brittlestems, Twiglets and Poisonpies, Inkcaps and Scalycaps, Cavaliers and Knights, Parasols and Puffballs, Oysters and Jellies. The next day I was building a bat box at the back of the Hive and found some Bird’s Nests. Yes, these were fungi too – little pots that start out with crusty tops like tiny orange creme brulees which disintegrate to reveal a cluster of whitish ‘eggs’, the spores, that ping out of the nest with a rain drop splash to start new growth somewhere nearby or get picked up on the feet or fur of a passing animal to set up elsewhere.

At this point you might be asking, if fungi mostly appear in the autumn, what are they doing for the rest of the year? Most of these fungi live under the ground or inside dead trees, and sometimes in the living ones too. They form tiny threads, hyphae, that can extend for considerable distances. The largest living organism is a Honey Fungus - one was found in America that was estimated to cover 3.7 square miles. The fungi we see in the autumn are the fruiting bodies that send out millions of tiny spores to start new growth elsewhere. The ‘fairy rings’ of mushrooms that are sometimes seen in the meadows and woods are the fruiting bodies of a single fungus that is living under the ground.

Since that walk with the experts I’ve been gripped. I particularly like some of the little jelly-like fungi that are usually found on fallen logs and dead standing trunks: the orangey-brown Wood Ear, the black, shiny Rubber Buttons, and small, spikey Candlesnuff that starts off white then turns black from the bottom up. A few days ago when Anne and I were coming back from checking on the dragonflies along the Highgate pond chain, one of the rangers, Scott, told us of a blue toadstool he’d spotted near the Viaduct Bridge. We rushed straight there and found a Blue Roundhead, Stropharia caerulea, absolutely gorgeous and the first time I’ve ever seen one.

Everyone’s favourite toadstool must be the Fly Agaric, or Amanita muscaria, its bright red cap covered in white spots like the Father Christmas of the fungal world. Look for it near birch trees where it forms a mutually beneficial, symbiotic, relationship by wrapping its hyphae round the trees’ root hairs. This provides the fungus with sugars from the tree in return for nitrogen and phosphorous from breaking down organic matter in the soil. The experts told me that the toadstool starts to form as a white egg-shape that pushes up from the ground. The white veil that covers it starts to split as the red cap pushes through, leaving bits of white stuck to the surface.

I couldn’t finish without mentioning another recent obsession: slime moulds. These enigmatic organisms used to be classed with fungi but they are now grouped with amoeba and other single-celled organisms because they spend most of their time singly, moving slowly through the soil and dead material feeding on microorganisms like bacteria and fungi and helping with decomposition. In this state they can’t be seen without a microscope, but at about this time of year they congregate into reproductive fruiting bodies to release spores that are dispersed by the wind. In the last week or so I’ve come across several different species, most with even more extraordinary names than those of the fungi: on dead tree trunks and logs I found yellow Dog’s Vomit (Fuligo septica), pinky-grey tiny blobs of Wolf’s Milk (Lycogala epidendrum), a large white Cauliflower Mould (Reticularia lycoperdon), and one with no common name, Badhamia utricularis, that dangled blue-grey balls from little stalks under the dead branch of an oak tree. I accept that fungi and slime moulds might not be to everyone’s taste, but what would our natural world look like if they weren’t there to recycle the dead matter?