Author – Page 2

Adventures of a clumsy person in far north Queensland (part 1): Horse-hair fungi

When you survey trees in a rainforest (and you are accident prone) you learn to walk through dense foliage with one forearm in front of your face. Sometimes you emerge with a tangle of lawyer vine whips wrapped around your wrist (which is preferable to having them wrapped around your head) and sometimes you emerge with a fist-full of what looks to be thick, coarse black hair. It very much resembles horse hair but it does not belong to any animal. It’s actually a mushroom! The aptly named, and surprisingly interesting, horse-hair fungus (Marasmius spp.).

Mushrooms play an important part in a rainforests life cycle. They are needed to decompose fallen logs and leaf litter in order for nutrients to be returned to the ecosystem. In fact one of the main chemical building blocks of plants, known as lignin, is so structurally complex that it can only be broken down by special groups of fungi known as white rot fungi (Floudas et al. 2012). Most mushrooms are found on the forest floor, which makes sense as this is where fallen leaves and wood all wind up – So what is this horse-hair fungi doing creating tangles among the tree branches? And why does it look like hair when it is supposed to look like a mushroom?!

To answer the second question first: there is more to mushrooms than just mushrooms. Mushrooms have long had a mystical aura about them because the appear so suddenly after the rain and seem to disappear almost as quickly. But nothing appears from nothing. Mushrooms actually grow out of a vast network of near-microscopic roots called hyphae. The hyphae are present in the soil all year round, they can cover vast distances and be densely packed – 1 g of soil can contain as much as 3 km of fungal hyphae (Bardgett 2005)! Hyphae are the part of the fungus that interact with plant material and can decompose fallen logs and leaf litter; the mushrooms are really just the showy reproductive organs of the that grow out from the hyphal networks in much the same way a flower grows on a tree.

So, the hairs of the horse hair fungus are these hyphae. But instead of being super-fine and delicate, they are thick and coarse to avoid getting broken to pieces by wayward ecologists tumbling through the rainforest. If you come upon them at the right time of year you will indeed find mushrooms sprouting from these aerial hyphae.

But why aerial hyphae? What’s wrong with using the ground? There are many species of Marasmius mushroom and they all specialize in left litter decomposition. The tangled networks of aerial hyphae, produced by the horse-hair Marasmius, act as nets that catch and ensnare falling leaves before they reach the ground. This strategy means that horse-hair fungi don’t have to compete for food or real-estate on the forest floor where competition is pretty high. By settling among the trees these horse hair fungi can have a space all to themselves.

Having your own private food-larder away from other competitors is a pretty nifty trick, however some horse hair fungi have been reported to be a bit more proactive than this. Horse-hair fungi associated with tea-leaf bushes have been shown to release volatile compounds that actually cause the tea leaves to drop off into the fungi’s waiting hyphae (Su, Thseng et al. 2011, Aubrecht, Huber et al. 2013). Smart huh? That kind of smart doesn’t go unnoticed and it seems that horse-hair fungi has caught the eye of the local birds.

When we found a nest in Far north Queensland that was lined with horse-hair fungi we thought that the birds had simply happened upon a nifty nesting material. But horse-hair fungi have shown up in nests all around the world and some researchers think that it may actually provide a benefit to the birds having water repellent properties (no one wants a soggy nest) and containing antimicrobial compounds that may help with nest hygiene (Aubrecht, Huber et al. 2013).

Horse hair fungi: loved by birds | a clever competitor | preferable to a face full lawyer vine

Dr Jen Wood
@JW_ilikedirt

Aubrecht, G., W. Huber and A. Weissenhofer (2013). “Coincidence or benefit? The use of Marasmius (horse-hair fungus) filaments in bird nests.” Avian Biology Research 6(1): 26-30.

Bardgett, R. D. (2005). The biology of soil : a community and ecosystem approach. New York, New York : Oxford University Press.

Floudas, D., Binder, M., Riley, R., Barry, K., Blanchette, R. A., Henrissat, B., . . . Hibbett, D. S. (2012). “The paleozoic origin of enzymatic lignin decomposition reconstructed from 31 fungal genomes.” Science 336(6089): 1715-1719.

Su, H. J., F. M. Thseng, J. S. Chen and W. H. Ko (2011). “Production of volatile substances by rhizomorphs of Marasmius crinisequi and its significance in nature.” Fungal Diversity 49: 199-202.

Photo credits: all photos by Jen Wood unless otherwise indicated

The wanderings of a Hugh Rogers fellow through a Melbourne-Boston Sister-City association

Hike:

Location:

Distance:

Trail type:

Highlights:

Mount Moosilauke, via Gorge Brook Trail

White Mountains, NH, USA

13 km

There and back again, possible loop

Moose, stunning uninterrupted views of the white mountains,

Want to follow in my footsteps? Learn more about this hike here. I practise leave no trace principles. Please respect the environment and learn how to do the same on your next adventure here.

Jenn on the snow-covered Gorge Brook Trail on the way to the top of Mount Moosilauke.

“Do you have microspikes?” Oh no I thought, not this again. This micro has nothing to do with microbiology, and everything to do with ice.

Last time I was asked if I had microspikes it ended in a hike involving climbing up and down frozen waterfalls. Yes, that sounds cool, and it is. But when you have developed a fear of ice it takes a little getting used to. This fear has developed while walking around Boston, as I am never entirely sure when I am going to end up on my butt from stepping on black ice. I am considering these microspikes, metal spikes that strap on to your hiking boots, might be an excellent addition for my daily walking commute to Harvard.

Today these microspikes are for a hike up Mount Moosilauke in the White Mountains of New Hampshire.

The trailhead is at the Dartmouth Moosilauke Ravine Lodge, a giant log cabin that welcomes anyone for something to eat or even to stay. No snacks for us here as the lodge is closed over winter. With this closure, the road in is also closed, adding a bit to your walk as you park off Ravine Road. Not to worry you might see a moose along the quiet road. Unfortunately, all we came across of these “mythical’ creatures was poo and hoof prints.

Once on the trail, you are surrounded by pine trees, a gentle bubbling creek and a gradual climb. You know you are close to the summit as the track steepens, the trees grow smaller, and glimmers of the surrounding mounts start to peek out through the trees.

The exposed ridge to the summit is dotted with large stone cairns marking the way. Thankful for the microspikes to safely traverse the tightly compacted snow and ice, we made it to the summit without being blown away. We couldn’t enjoy the stunning 360-degree views for long as it was blowing blustering gale-force winds. Conditions common for the Moosilauke peak and unsurprising as just a hop, skip, and jump away on the top of Mt Washington has recorded the second-highest wind speed measured anywhere in the world of 372 km/h.

Well worth the visit, the summit offers up stunning views in all directions. Being the western most of New Hampshire’s 48 peaks and the 10th highest, you have stunning vistas of the mountain ranges – on a clear day like ours we could see some of the Adirondack Mountains of New York and the Green Mountains of Vermont. But the best was the view to the west taking in Franconia Ridge.

We had considered doing this hike as a loop, circling back to the ravine lodge via the carriage trail, but with the wind howling up that side of the mountain, and being an exposed trail, we decided the more pleasant option would be back down the protected route we had taken up.

The wind blown ice castles on the summit of Mount Moosilauke.

It wasn’t just the stunning views that captured my attention on the summit. The natural ice sculptures created by the wind, looked like built structures, making me think of ice castles. But what is cool, is that even on a microscopic level these can be considered castles. The individual snowflake is an ice fortress built for a microbe. Bacteria and dust floating in the air act as nucleation sites for the formation of snowflakes.

A common snowflake inhabiting microbe is Pseudomonas syringae, a rod-shaped, Gram-negative bacteria. Don’t worry, no need to stop catching snowflakes on your tongue, as P. syringae is not a superbug, instead it devastates our crops. It does have a superpower though – it can turn water into ice. This super power means that is a fantastic snowflake nucleator.

P. syringae produced its own ice castles through a protein on the bacterial surface – the outer cell membrane protein, inaZ. The surface of inaZ mimics ice, this mimicry of structure causes water molecules that come into contact with it to arrange themselves like an ice lattice. Water molecules that have been templated into this lattice formation become ice quicker. Thus, freezing at lower temperatures and becoming a snowflake quicker. It is this protein on P. syringae that means they are able to transform water vapor into ice at temperatures higher than cloud freezing, creating their snowflake ice castle.

The inaZ protein enables them to make more snowflakes than other ice nucleators – like dust or pollen. This has made them a key component of our man-made snowfields – P. syringae is used to make Snomax, a product that enhances snowmaking, perhaps even used at your local snow resort. This bacterial protein may be a helpful factor for the future of snow play in Australia with the ever-warming winters means less snow. This little microbe may just help ensure your next skiing adventure and even that next rain.

Mini city of fungi and lichen peeking out through the snow on Mt Moosilauke.

Mount Moosilauke

This adventure was made possible by a Hugh Rogers Fellowship, from the Melbourne Boston Sister City association.

Media Coverage of Jenn Payne’s Hugh Rodgers Fellowship:

Want to start your own adventure in Boston? Apply for a Hugh Rodgers Fellowship! They are not just for scientists- these fellowships support education and the arts too.