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!

Today's Fun Fungus Walk

Our own Joan Marie Galat is a scholar of all things fungus. And she still knows how to enjoy just finding the odd mushroom here and there while out for a walk in the woods. Here are some photos she shared recently with friends. With compassion for those of us who can find it hard to figure out Latin names for various species of living things, she's captioned these photos in a more informal way.

 "Bite marks?"

"A colony."

 "A super-colony!"

 "Notice the rarely-seen upside-down bottlecap mushroom."

"The funnest of fungi!"

You can also explore the outdoors, including trees, wildlife, and the night sky, through the pages of Joan's books [https://www.joangalat.com/view-books/] . Her comments there are considerably more precise, and very interesting!

Read It and Weep: Fungal Guttation

by Jan Thornhill

Young Red-Belted Polypore (Fomitopsis pinicola) with guttation drops

Some fungi are prone to exhibiting a curious phenomenon—they exude beads of moisture, called guttation. In several polypores, such as Fomitopsis pinicola, the liquid produced can look so much like tears that you'd swear the fungus was weeping. Or maybe sweating. Other species produce pigmented drops that can look like milk, or tar, or even blood.

Guttation is more well-known in some vascular plants. During the night, when the plant's transpiration system is shut down, pressure from excess moisture in the roots can force beads of sap out of special structures on leaf edges. 

Guttation droplets on strawberry leaves (Noah Erhardt/Wikipedia)

In fungi, the guttation mechanism is not so well understood. In many species, however, it's so often observed, particularly during times of rapid growth when temperature and humidity are favourable, that these beads of liquid can be a reliable macroscopic characteristic. Hydnellum peckii, for instance, so frequently "bleeds" pigmented drops in its early stages of growth that it's been given gruesome nicknames, including "Bleeding Tooth Fungus" and "Devil's Tooth." Coincidentally, a 1965 study found a compound in the fruiting body of  H. peckii that has anticoagulant properties similar to those of heparin, too much of which can make one bleed to death internally.   

Bleeding Tooth Fungus (Hydnellum peckii) produces red-pigmented 
guttation droplets during periods of rapid growth. (Lisa Neighbour)

A couple of years ago, I came across a crop of Inonotus glomeratus on a maple log. I'd found this amazing polypore a few times, once right after it had showered itself, and everything else around it, with millions of sulphur-yellow spores. The one I'd found, though, was very young, and instead of spewing spores, it was weeping globules of "tar" in copious enough amounts that shiny black pools were accumulating on the forest floor. Unlike most guttation drops, which are watery, these exudations were thick and sticky and stained my finger and thumb a deep auburn brown. And kind of glued them together. Oddly, though this unusual guttation has been noted by others, there seems to be no mention of it in the literature. I. glomeratus is so unusual in so many ways, I ended up writing a whole post about it.

Fast-growing Inonotus glomeratus produces tarry guttation.

This Inonotus glomeratus continued to drip its viscous black exudate
even after it began releasing its yellow spores.

The guttation drops on this Inonotus glomeratus were so thick that the fungus grew
around them, producing a pitted appearance after rain washed them away.

Polypores and Hydnoids are not the only fungi to produce guttation. In moist conditions, young Suillus americanus stipes can be heavy with yellow-tinted drops. Guttation is also common enough in the uncommon Rhodotus palmatus that this characteristic is often included in descriptions. 

Chicken Fat Suillus (Suillus americanus) 

Wrinkled peach (Rhodotus palmatus) 

Guttation can happen in incredibly small ways, too. During the Toronto Bioblitz a few years ago, we found some Lachnum subvirgineum that, despite what seemed like dry conditions, were covered in minute guttation droplets, as were most other Lachnum I've since come across. 

The largest of these Lachnum subvirgineum was less than .5 mm. in 

diameter, which makes the guttation droplets impressively small.

Another minute character is so characteristically bejewelled in guttation droplets, it's named for it: Pilobolus crystallinus, which is one of the "Cannon" or "Hat Thrower" fungi found on herbivore dung.

Dung-loving Pilobilus crystallinus, is named for its sparkling
guttation droplets. (See my post about this remarkable,
tiny fungus, also called Hat Thrower, or Cannon Fungus)

Though little is known about guttation in wild fruiting bodies of fungi, it's a common phenomenon of fungal mycelia and hyphae in the lab, and a number of studies have been done to determine what the exudates contain. Penicillin has been found in the guttation droplets produced by Penicillium species in similar concentrations to that found in the culture broth, while gliotoxin, which has immunosuppressive qualities, has been found in guttation droplets of Aspergillus fumigatus. Do these fungi use guttation droplets as reservoirs for metabolic byproducts, or do they simply use them for water storage? 

Or have different species evolved to produce guttation droplets for different purposes? The edible bolete, Suillus bovinus, for instance, has been shown in the lab to reabsorb nutrients from its guttation droplets, while leaving behind less useful byproducts, such as oxalic acid. So perhaps guttation has evolved as an efficient method of expelling waste for some fungi. 

Is that what's going on with Inonotus glomeratus? Is that viscous, black ooze just a collection of rejected metabolic byproducts? If anyone would like to analyze it and has the means, I have some dehydrated exudate that I'd love to send you!  

Even some slime moulds, like this immature Stemonitis 
flavogenita, produce guttation droplets. (Ulrike Kullik) 

Pink-pored Fomitopsis rosea are even prettier when 

decorated with shimmering beads of moisture. I think the 
pattern on rim was made by the "teeth" of a grazing slug.

Tree Bacon (Punctularia strigosozonata) "bleeds" rust-tinted droplets.

Early nubbins of an unidentified polypore exude milky drops.

This Red-belted Polypore (Fomitopsis pinicola) produced guttation 
droplets for three months one summer. When it finally stopped, 
trompe l'oeil teardrop-shaped indentations were left behind.

Wet weather makes Xylaria hypoxylon produce beads of moisture.

This large Pleurotus dryinus was weeping copiously
despite there having been no rain  for a week.

Many parasitic Hypomyces, such as this H. chrysospermus, are prolific weepers. 

Inonotus dryadeus is a lumpy polypore known for its ample
 production of amber guttation droplets. (Wikipedia)

The Jack-o-lantern Mushroom (Omphalotus illudens) not only
glows in the dark, it also produces orange-staining guttation.

The Resinous Polypore, (Ischnoderma resinosum), is also named
for the droplets it produces when very young.

The reddish-rimmed gills of this group of Mycena
leaiana produced tiny white droplets. 

Even the hairy asexual form of Postia ptychogaster produces guttation.

Selected References:

Erast Parmasto, Andrus Voitk, (2010). Why Do Mushrooms Weep? Fungi, Vol. 3:4

Hutwimmer, S., Wang, H., Strasser, H., Burgstaller, W. (2010) Formation of exudate droplets by Metarhizium anisopliae and the presence of destruxins.Mycologia, Vol. 102 no. 1, 1-10

Gerhard Saueracker. On the Exudates of Polypore Fungi. Fungimap Newsletter 48, Jan. 2013

(NB: This is a slightly edited repost from my other blog: Weird & Wonderful Wild Mushrooms

Stories in Slate: Touring an Underground Mine

By Marie Powell (Photos by L. L. Melton)

A tour of an underground mine offered a hands-on science opportunity during a recent trip to the Braich Goch slate mine in North Wales.

We spent more than two hours in the mine tunnels with our expert guide Mark of Corris Mine Explorers. During that time, we explored the abandoned caverns, learned a little mining history, and examined original artifacts used in this once-prosperous slate mine.

The underground tunnels date to 1836, and by 1878 the mine employed about 250 workers producing 7000 tons of slab and roofing slate. In its heyday, families negotiated for mining rights to the chambers, which were known as "bargains," Mark told us. Men and boys aged 10-35 worked the mine in near darkness, hoarding the tallow candles made from sheep fat that provided their only light source. They used clay to carry the candle with them and fix it to the slate walls of the mine as they worked

We had a chance to see several original artifacts used in the mine and left there. These tools date back to the 1860s, Mark said. Using the mallet, a worker would strike the rod three times, then turn and strike three more, for a total of nine strikes. Black powder was packed into the hole. They used copper and brass rods because they don't spark, he added.

Since the mine is full of ledges and drops, and candles were scarce, it was important to have a reliable method of finding their way around the mine in almost total darkness, he said. They used a form of echo-location, orienting themselves to the sounds of dripping water in the cave, or to their own singing.

Most of the time we were able to walk upright, but at times there was barely enough room for a person to crouch. At one point Mark tied us to a rope and let us look out over a drop in the mine to a level below. Staring down at the eerily echoing caverns far below us, we were glad of our headlamps and gear, and hyper-aware of the danger the miners faced every day.

Artifacts lined the mine at strategic locations. Mark pointed out the expected ones, such as a detonation box, explosives, and a "bugle" of black powder. Among the artifacts we saw a 19th Century example of recycling: a jar for W P Hartley's marmalade, probably re-used for drippings from sheep fat, since bread and drippings were a staple of the miner's diet.

These historical artifacts also show the effects of rust, which occurs when water and oxygen goes to work on iron, especially cast iron as would have been the case in the late 1800s.

The walls themselves are a study in stratification, or the layers of rock that form over time. We stopped more than once to examine them.

Mushrooms were visible in several places as well, and Mark pointed out that these fungi can act as agents of erosion on some artifacts, such as this oxidizing nail covered in what looked like red-orange fuzz.

The ochre coloration, generally from iron oxides or limonite, gave the walls of the mine a striking look in places as well.

The geological processes we could clearly see at work in this underground environment made it well worth the trip, and having a knowledgeable guide willing to let us explore at our own pace was invaluable.

Marie Powell is the author of seven books for children, including Dragonflies are Amazing (Scholastic Canada) and a six-book Word Families series (Amicus Publishing). 


http://sci-why.blogspot.ca/2014/01/stories-in-slate-touring-underground.html

Creepy, Eerie, Macabre Fungi for Halloween

Jan Thornhill

(This is a repost of the October 2013 one that somehow disappeared.)

Picture this: You’re in an unfamiliar part of the woods, alone. It’s spooky and dark. A storm is brewing. You hear something, stop dead in your tracks. Was it a howling wolf? Or just the wind? You’re alert now, all your senses are alive. And then you get a whiff of something—something so awful it makes your nose curl: the stench of rotting flesh, a nearby corpse. But where is it?

And then you see something…but it's not a corpse, though it's almost as grotesque. What you’ve found is a stinkhorn.

Two stinkhorns—Phallus ravenelii, with feasting slugs,
and Clathrus archeri (photos: Jan Thornhill; Wikipedia)

Stinkhorns are one of the more wondrous fruits of the fungi kingdom. They come in a bizarre variety of shapes, ranging from cage-like structures to tentacled stars that look like space aliens to rude-looking columns, some of which are dressed in lacy hoop skirts. Whatever their form, they all erupt—sometimes overnight—from an “egg,” and they all, at some point in their development, are covered in gross-smelling slime.

More traditional fungi rely on air currents to disperse their minute spores. Not the stinkhorn. A stinkhorn’s spores are imbedded in its stinky slime, disgusting muck that so closely mimics the smell of a decomposing cadaver it quickly attracts flies and other insects. When these insects take off again, they unwittingly carry away the stinkhorn’s spores stuck to their mouth parts and their tiny insect feet, spreading them far and wide. 

Stinkhorns are not the only macabre fungi you can come across in the woods. Walk farther and you might stumble upon some aptly named “Dead Man’s Fingers.” 

Dead Man's Fingers—Xylaria polymorpha (photo: Ulrike Kullik)

Properly called Xylaria polymorpha, these fungi are hardwood decomposers. They’re most often found on rotting logs, but when they grow from buried wood they can eerily resemble the blackened fingers of a corpse struggling to dig its way out from a forest grave. Unlike stinkhorns, which can pop up and then deteriorate in a couple of days, Dead Man’s Fingers are so horny and tough they can persist for months, or even years. 

And then there’s the Bleeding Tooth fungus.  

The spores of the Bleeding Tooth Fungus, Hydnellum peckii, are produced
on tooth-like projections beneath the cap. (photo: Darvin DeShazer)

The first time I stumbled upon one of these, it was so covered in “blood” I thought I’d found something recently killed. Though Hydnellum peckii, when fresh and moist, exudes something that looks shockingly like what oozes out of a slaughtered animal’s veins, the globules of pigment-filled liquid are nothing like animal blood. There is, however, a compound in these fungi that can affect blood. This compound, called atromentin, has anticoagulant properties similar to those of heparin, a medication used to prevent blood clots. Ominously, though, an overdose of these anticoagulants can cause a patient to bleed to death.

Some Omphalotus species, or Jack-O'-Lantern mushrooms,
glow in the dark. (photos: Thomas Schoch; Noah Siegel)

The fungi world provides even more Halloween-appropriate characters. In daylight, some of these look like perfectly normal mushrooms. But if you happen to be out for a midnight woodland stroll without a flashlight, you might be frightened by an eerie glow emanating from the base of tree—a glow produced by bioluminescent fungi. Scientists don't yet know why more than 70 species glow in the dark, but one idea is that their light might attract nocturnal insects that could help spread the mushrooms' spores. 

But the prize for the most frightening, the most macabre, the most fiendishly devious fungi has to go to the Zombie Ant Ophiocordyceps. 

The fruiting body of a Zombie Ant Ophiocordyceps protruding
from the head of a dead ant. The white nodules are another
parasitic fungus—a parasite of a parasite! (photo: David Hughes)

The Cordyceps family of fungi are parasites, and their chosen victims are often insects. But what makes Ophiocordyceps so unforgettable, and so nasty, is that after it has worked its way inside an ant's body, it travels to its brain, where chemicals are released that control the ant's actions. The now "zombified" ant is compelled to walk a distance from its colony, and eventually latches tightly onto a leaf with its mandibles. It will never let go. The fungus continues to grow, killing the ant and producing a fruiting structure that sprouts straight up out of the insect's head. The fungus then produces spores that are dispersed by air currents, so the fiendish cycle of Zombie Ants can continue. But, wait! There's some comeuppance for the dastardly Omphiocordyceps: a completely different parasitic fungi preys on it, reducing its ability to produce mature spores!    

For more information about fungi in general: http://www.mushroomexpert.com/

For more information about Zombie Ant Fungi: http://ento.psu.edu/directory/dhughes