Päiväkirja-arkisto kohteelle syyskuu 2019

syyskuu 26, 2019

July Salt Spring Island Fungus Of The Month: Russula Emetica

Salt Spring Island had a fairly wet July, and there were several fresh mushroom sightings, including a bunch of red-capped Russulas. Unfortunately, squirrels, slugs, and deer seem to have enjoyed them as well, so exact identification might be tough. They may be Russula emetica, quite common on the island, or a close relative.

Russulas are ectomycorrhizal fungi; they live in symbiotic partnership with trees. The threadlike roots of the fungus (hyphae) wrap around the roots of the trees and branch out into the soil. The fungus collects water and minerals like phosphorus with its web of fine roots and shares it with the tree; the tree creates sugars from carbon dioxide via photosynthesis and shares them with the fungus in exchange.

Ectomycorrhizal fungi can connect to more than one tree at a time. Dr. Suzanne Simard at the University of British Columbia and her graduate students have done some really interesting experiments on the network of individual fungi that connects trees in a forest. Here is a map they made of the fungal connections between Douglas Fir trees in a forest plot, by testing the roots of each tree for fungus DNA to see which individual fungus connected where:

Simard's research group found that the oldest trees in a forest, which they call Mother Trees, send nutrients and sugars through the fungus networks to seedlings. If the scientists fertilize one of the Mother Trees with a special rare form of nitrogen, they will find that kind of nitrogen showing up in the newly-grown leaves of baby seedlings and small trees nearby, and young trees planted near a Mother Tree grow much faster than trees planted further away. This is important for seedling survival, because when they are very young on the forest floor, they might be too shaded to receive enough sunlight to feed themselves.

They even found that different species of trees in a forest share nutrients. Douglas firs share sugar with birch trees in fall and spring, when the birch trees are leafless, through the fungal networks. But in summer, when the leaves are densest and sunlight is scarce, the fungi carry sugar from the birch to the Douglas fir.

There are few birch trees on SSI, but perhaps something similar happens with alders here. I hope they look into it.

These fungal networks moving sugar between trees also support sneaky freeloaders, like this eerie-looking ghost plant:

Observation by dianalynn1

It looks completely white because it has no leaves or chlorophyll at all. Unlike most plants, it does not turn sunlight into energy. It gets all its energy and nutrients by stealing them from underground Russula fungi, and the Russula got the sugars from trees.

This corallroot is another sneaky not-green-at-all plant that steals nutrients from Russula underground instead of photosynthesizing:

Observation by eacameron

It's quite impossible to grow a ghost plant or a coralroot in a pot, because it needs a Russula to steal sugar from, and the Russula needs a tree to connect to. It takes a forest to grow a Russula, and it takes a Russula to grow a forest.

Julkaistu syyskuu 26, 2019 12:21 AP. käyttäjältä corvi corvi | 0 kommenttia | Jätä kommentti

syyskuu 28, 2019

August Salt Spring Island Fungus of the Month: Fomitopsis pinacola

August's Fungus of the Month is this young Fomitopsis, beaded with liquid even during the dryest part of the year. It's too young to tell which exact species this is, since it hasn't formed a cap yet. Fomitopsis, especially the Fomitopsis pinicola complex, are well-known for producing liquid.

observation by dianalynn1

The secretion of liquid by plants or fungi is called "guttation". It is not purely water; it is often pigmented and may contain chemicals manufactured by the fungus. Penicillium species secrete penicillin in their guttation.

Here are a few more bracket fungi seen on the Rock with guttation droplets:

observation by caladri

observation by caladri

observation by caladri

It's not just bracket fungi; many other species are known to exude droplets. The most dramatic example is Hydnellum peckii, the Bleeding Hydnellum, which produces copious and ominous red guttation. The pigment that gives the droplets their colour is atromentin, which is an anticoagulant. Consuming enough atromentin from a Bleeding Hydnellum would also cause internal bleeding in a human, though they taste so terrible there are no recorded poisonings. There aren't any observations of it listed on this site from Salt Spring Island, but it is occasionally seen on Vancouver Island, and could occur here as well. Here's one from Vancouver Island:

observation by jeremy_sea

I'd love to go into the science behind guttation. However, this is going to be a short post: we don't know why fungi do this, or whether they all do it for the same reason. For more information, here's a great article by Jan Thornhill discussing what little we know and the ongoing research.

Julkaistu syyskuu 28, 2019 11:46 IP. käyttäjältä corvi corvi | 0 kommenttia | Jätä kommentti