Love forests? Thank fungus!

At first glance, the mushrooms we see popping up on the forest floor may appear pretty insignificant. They’re lovely, sure, but most are small and rubbery, and they disappear pretty quickly during dry periods.

As it happens though, these little nubbins are crucial to our forests’ very SURVIVAL. How is this possible? Let’s dig a bit deeper. There are thousands of mushroom species, which are part of the Kingdom Fungi. Most live in the soil or on other living things like trees, and they feed mainly on dead matter. Unlike animals, they digest food outside their bodies, using chemicals to break down their meal before consuming it.

Trees and mushrooms help each other. Guess what else they have in common? A fruit to plant ratio!

Yes, some cause disease, but there are so many more helpful mushrooms than harmful ones. Our debt to our fungal friends goes back hundreds of millions of years, when life first started moving out of the oceans and onto land. Plants could not have made that leap without mushrooms first creeping onto the rocks and digesting them into nutrients (i.e. plant food, like phosphorus or magnesium). This allowed plants to move in, dry off, and, over millions of years, diversify into the incredible environments we enjoy today.

There are two main ways that forests STILL depend on mushrooms:

1. Mushrooms decompose dead things. Think of all the leaves that fall and the plants and animals that die in the forest every year. Without decomposers, they would just lie there, eventually piling up enough to smother the forest itself. Luckily, fungi break it all down to nutrients that get recycled back into the forest system, supporting new life. Other critters like worms and beetles decompose dead things too, but — not to play favourites or anything — mushrooms do it the best.
2. Many mushrooms actually feed trees. That seems strange- what could fleshy little mushrooms have to offer towering trees? Here’s the thing: the mushrooms we see are only the reproductive bits attached to the main fungal body — called mycelium — which can be ENORMOUS! They’re similar to apples in this way, they make up just a small part of the entire apple tree.

The mycelium stays mostly out of sight — underground or inside trees — and is made up of thin, quickly-growing strands that look a bit like cobwebs. They can squeeze their way into the tiniest underground nooks and crannies, and are about 100 times better at getting water and nutrients from the soil than are the relatively shorter, stubbier tree roots.

So mushrooms gather water and nutrients for trees and deliver them right to their roots. Why so helpful? Trees give something back! Through photosynthesis, plants take carbon from the atmosphere to make carbohydrates (i.e. sugar), the main building block of plants. Most trees make extra: they give sugar to mushrooms, and mushrooms give water and nutrients to trees — a sweet deal!

These tree-fungal relationships are called mycorrhizae, and they benefit the vast majority of trees and other plants. Often neither the tree nor the mushroom could survive without the other! In harsher environments (like, let’s face it, Canada’s), forests really depend on mushrooms to stay healthy.

And who depends on forests? We all do! For clean air, biodiversity, climate regulation, food, lumber, and medicines to name a few. One thing that’s very clear — we have a lot to thank mushrooms for!

Colourful Wood: Spalting Fungi

by Jan Thornhill

Chlorociboria produces gorgeous blue-green fruit bodies.

It’s easy to forget while collecting fungi that the ones we find growing on wood and elsewhere are only their fruiting bodies—the actual organism is usually hidden, its mycelium buried deep in wood or soil. But the microscopic mycelium of some wood-loving fungi make it very clear just how large an area they’ve taken over by staining the wood they’ve colonized. This staining, which can sometimes be dark lines, other times extensive areas of colour, is called spalting.

Wood stained blue-green by the fungus Chlorociboria.

The fairly common Chlorociboria aeruginascens and its sister C. aeruginosa, which can only be differentiated microscopically, stain the wood they’ve colonized a stunning blue-green with the pigment xylindein. This beautiful blue wood has been used by woodworkers since at least the 15^th century, primarily in inlays (see examples here). It’s such a striking colour that studies are underway to find a way to inoculate various forest trees with Chlorociboria to enhance the value of the lumber. I used to be impressed that anyone had ever found a piece of this blue wood in good enough shape to use for anything other than as a conversation piece. Until last year, whenever I found it, the wood was already so decomposed I could easily pull it apart with my fingers.

And then I came across this oak tree that had fallen across a park path:

Ruby & Fritz inspecting spalted log

Though the colour of this Chlorociboria spalted log is a much
darker than usual, the wood is still usable.

And then I discovered a much more uncommon disc fungus that also stains wood.

Patinellaria sanguinea stains wood coral red. 

I had found a mystery purple crust growing on a branch in the fall. I couldn't get any spores from it to aid identification, so I wet it and put it in a plastic container, hoping that by giving it a little warmth and moisture it might revive and offer me some spores. The only thing that happened was that it started decaying. I was about to relegate the branch to the kindling pile when I noticed that in a couple of places its surface was oddly coloured with reddish-pink spiderwebby fuzz. I assumed this was just an unusual mold, but when I got out my loupe to inspect it I was surprised to see a multitude of minute blackish discs embedded in it. Hmm.

Amazing colour of "black" Patinellaria sanguinea fruit bodies under the microscope.

When I put a sample under the microscope I immediately saw that the pink fuzz was not a mold, but a hyphal mat, or subiculum, that clearly belonged to the blackish discs. Not only that, but, when sectioned, the “black” discs were actually quite strikingly coloured. There were even some asci and spores.

Wood stained, or spalted, by Patinellaria sanguinea 

None of my books gave me a name, so I got out my knife out and carved a few chunks off the branch to dry for later study. It was only then that I realized my little ascomycete had stained the wood a gorgeous coral red. 

Days passed. I was doing an unrelated image search for another minute black disc, Patellaria atrata, when halfway down the page a picture jumped out at me. It clearly showed exactly what I had accidentally grown—mini blackish discs with a pinkish red subiculum. And they had a name. Panitellaria sanguinea. 

I have not been able to find out much about this little curiosity, which has also been known as Durella sanguinea and Peziza sanguinea, other than that it’s rare, grows in North America and Europe, and apparently prefers hardwoods. 

A number of common wood-decaying fungi spalt wood with black
lines – barriers that keep other fungi out of their "territory."

Spalted wood created by several different
species, including Chlorociboria.

(N.B. This post appeared in a slightly different form on my blog, Weird & Wonderful Wild Mushrooms)

More Info:

Tom Volk’s Chlorociboria page

Panitellaria sanguinea on Mycoquebec

Panitellaria sanguinea on Mycokey
Robinson, S.C., Tudor, D., Snider, H., Cooper, P.A. 2012. Stimulating growth and xylindein production of Chlorociboria aeruginascens in agar-based systems. AMB Express 2(15).
More about spalting: Northern Spalting
George Grant Hedgcock. "Studies Upon Some Chromogenic Fungi which Discolor Wood." St. Louis, 1906

Hair Ice and Singing Lakes and Icebergs: Fabulous Ice Phenomena

Jan Thornhill

Hair ice growing from twig.

Antarctic sea ice (NASA)

My friend Ulli called one chilly morning a couple of weeks ago and said she’d found a stick in the woods for me. “A stick?” I said.

“You want it,” she said cryptically.

She was right. Though what she brought over ten minutes later looked like an ordinary piece of a dead alder branch, part of it was not ordinary in the least. One end had sprouted a glorious tuft of long silky white hair. Ulli had found hair ice!

Hair ice starting to melt. (Jan Thornhill)

Though you might think at first glance that hair ice is some kind of peculiar frost – it’s not. Frost forms when moisture in the air freezes on objects. Hair ice, on the other hand, starts from the inside and moves outwards. Moisture in a stick or twig is exuded through minute pores on the surface, and when this moisture hits humid sub-zero air the result is very fine filaments of ice that can grow up to five centimeters in length – filaments that look just like hair. It’s an uncommon phenomenon, and not just because weather conditions must be absolutely perfect. Here's the real glitch: the appearance of hair ice seems to be dependent on, of all things, fungi.

Hair Ice and Fungi

So what do fungi have to do with it? The idea that “a fungus participates in a decisive way” in the formation of hair ice, was first suggested in 1918 by the brilliant interdisciplinary scientist Alfred Wegener (who developed the theory of continental drift), but was unproven. Recently though, Gerhart Wagner and Christian Mätzler from the University of Bern have been studying "haareis" and its relationship to fungi. In one experiment they collected a number of twigs that had previously grown hair ice and treated them variously with three agents known to suppress the growth of fungi – heat, alcohol, and fungicide – while keeping a portion of each twig aside as a control. Afterwards, they froze all the samples under identical conditions, then compared the results. Sure enough, only the untreated pieces re-grew luxuriant manes of ice. 

The two scientists theorize that the living mycelium of various fungi within the wood (i.e. Exidia glandulosa or Tremella mesenterica) continues to metabolize at near freezing temperatures, producing heat and gases that force moisture outwards. When this moisture escapes through pores and comes into contact with humid below-freezing air, hair ice grows.

Hair ice that grew overnight. (Jan Thornhill)

After reading about Wagner and Måtzler's success at coaxing hair ice to grow in the laboratory, I decided to try to try a simple experiment of my own. I soaked the stick Ulli had brought me in water (its original hair ice having quickly melted). I then laid it on a wet paper towel on a plate and put it out in our unheated boot room, then waited for the temperature to drop. By the 10:00 pm the whole stick was sprouting hair ice. By morning I had a new pet!

The end of the twig  formed solid globules of ice, possibly
because moisture was released too quickly to form hair ice. (Jan Thornhill) 

Singing Lakes

A few days later, another friend was talking about how much he loves the quality of the human voice outside on cold winter days. The topic of walking on frozen lakes came up. I asked if he’d ever heard a frozen lake “sing.”

Frozen lakes sing! (Nentori)

I’ve heard it several times – haunting, otherworldly sounds caused by ice expanding and contracting, which is most common when there are major fluctuations in temperature. The best sounds, and the ones that carry the furthest, occur when there is no snow cover – rare conditions on the lakes near where I live, but not unheard of. Listen to Andreas Bick’s extraordinary recording of this phenomenon on a lake in Germany here. Turn up the volume and brace yourself!

Antarctic Ice & Animal Sounds

Weddell seals whistle and chirp.

And then I discovered something even more wonderful: The Alfred Wegener Institute (yes! that's the same Alfred Wegener as mentioned above!) that co-ordinates German polar research in both the Arctic and Antarctic has an acoustic laboratory in Antarctica. They are always recording – and on their website they offer this MP3 audio livestream of Antarctic ice and animal sounds from near the Neumayer Station on the ice shelf of Atka Bay. You can listen to the under-ice sounds of the Antarctic in real time! I can't turn it off!

All of this icy stuff is so cool it warms my heart. 

More Links:

This page from the Alfred Wegener Institute has sound files of various seal and whale noises to listen for on the live audio feed, as well as rubbing ice, singing icebergs, and some “mystery” sounds that are truly astonishing.

Download Gerhart Wagner and Christian Mätzler"s paper,  "Haareis auf morschem Laubholz als biophysickalisches Phanomen"  or  "Hair Ice of Rotten Wood of Broadleaf Trees – A Biophysical Phenomenon" – lots of pictures, though only some parts are in English.




Weddell seals source: http://commons.wikimedia.org/wiki/File:Diving_weddell_seals.jpg