akumar's Journal

5/8- today we learned about fungi with Joe Ammirati.

fungi have a commitment to making a lot of spores- a single puff ball can have one trillion of them!

their primary function is as a decomposer- breaking down dead organic material (saprothrops), especially of woody materials (dead trees, snags, logs, wood chips)- or in other words, carbon.

they are biotrophs, meaning that they require a living host (symbiotic organisms).

there are both native and invasive fungi.

there are three different types of fungi: soft rot and brown rot, which are fungi that don't break down lignan, therefore leaving unaccessed carbon left in the wood) and white rot fungi, which can strip away all the lignan and break down wood completely. this is very important to forest ecosystems, as white rot fungi are the main organisms that break down wood and restore the materials to the ecosystem.

we drew a picture of a spore and talked about the hyphae tips that extend into the ground. they absorb carbon by releasing enzymes from hyphae that break down compounds into things they can absorb, like glucose. they also use these tips as sensors in the ground.

we then went on a field trip outside to see different kinds of fungi in action. the first stop was in the grassy area by the fountain that had artist's conch (Ganoderma applanatum) growing inside crab apple trees. G. applanatum is a white rot fungi that can hollow out trees (eats their interior), but doesn't kill their hosts.

white rot fungi tend to favor angiosperms.

the next one we saw was another white rot fungus, oyster mushroom (Pleurotus pulmonarius), which was growing on a piece of wood near the UW Farm. oyster mushrooms can grow in almost anything, and can produce a toxin to attack nematodes.

another white rot fungus we saw was turkey tail (Tremetes versicolor) also on a log at the UW Farm. it's a very efficient fungi and does not like conifers.

we also saw huge families of Agrocybe praecox mushrooms in clusters under cedars of lebanon trees outside of benson hall. they were growing in beds of cone scales from the trees above. we uncovered the top layer of scales/organic matter (only an inch or two) to find that the soil was filled with networks of mycellium. all of the mushrooms here were probably genetically identical.

further along we found some split gill mushroom (Schizophyllum commune) on a dead limb on the ground (also a white rot fungi). they grow their gills facing down towards the ground, so that they fruit on the bottom of the limb only.

species list:
Agrocybe praecox
Schizophyllum commune
Tremetes versicolor
Ganoderma applanatum
Pleurotus pulmonarius

5/10- today was learning about fungi continued, this time with Noelle.

fungi can be anywhere from commensal to parasitic (all fall somewhere on that scale). we learned about several different kinds of fungal relationships:

1) fungus + root = mycorrhiza, whereby fungi takes carbon from the root of the plant and helps to transfer water and minerals in turn.

2) lichens = a fungus + a green alga or a cyanobacteria
they get wet and absorb pollutants, especially sulfur gases. that's why they are sparsely populated in urban areas with pollution.
there might be about 15-20 species of lichens on campus- you would find these to be more resistant to pollution than the kinds you would find in the forest.

3) hollyhock rust (Puccinia malvacearum) is a plant parasite. this fungi will not kill its host plant, can be very orange in color, the spores reinfect the plant that it is on (commonly hollyhock), and the hollyhock plant we looked at near the UW Farm also had white flies on the bottom.

4) powdery mildews are also plant parasites. they are very opportunistic- so they might appear when a plant is already weak or vulnerable. they go into cells and absorb the nutrients from living cells. the white color you see are hyphae. the mildew is just piles of spores that can break off easily (from wind, etc) and travel around- they are probably asexual spores.

we learned that birch trees must have micorrhyzal fungi, as do most wild trees. ectomycorrhiza means that it is outside of the root, while endomycorrhiza means that it is inside of the root. ecto- actually reshapes the root itself, to make it more short and stubby, which we saw on the roots of baby birch trees.

an interesting fact we learned was that if you fertilize a plant really well, they can kick their mycorrhizae out, because they're getting all their necessary nutrients.

mycorrhizae produce mushrooms to reproduce, like porcini, chanterelle, etc.

we spent the last few minutes talking about lichen- whose morphology can change in polluted areas. in other words, what you find in the city will look different from what you find in the forest, even if the species is the same.

they can grow on rock and other surfaces that are hard for others to grow on, as well as grow in harsh conditions. they are a primary successional species.

species list:
Puccinia malvacearum
powdery mildew diseases are caused by many different species of fungi in the order Erysiphales