Fungi Ecology

[Population, Density, Diversity][Interactions][Importance]


This is a picture of an Agrocybeparasitica
http://www.fungi.co.nz/

Population, Density, Diversity

There are over 100,000 different known species of fungi. Thus, it has been somewhat difficult for ecologists to gather up and organize information regarding the fungus kingdom and its diversity, or a species of fungus as a community. Because there are so many variations of fungi and it is such a spread out kingdom, it is also difficult to give a general depiction of the way fungi interact because they take precedence in so many different scales of environments.

The most common form of fungi is the standard mushrooms (stem, cap, gills). However, not all mushrooms have stems. Some species of fungus that grow on wood have caps that grow directly out from the wood. The cap may also vary from being semi-circular to being circular. It's shape depends on where on the wood it grows. However, apart from the different types of mushrooms, there are also a variety of other forms of sporocarps. However, when a sporocarp is spotted, only the spore-producing part of the fungus is shown, with an out-of-sight mycelium around whatever the sporocarp is growing from.

There are three main groups in which fungi are classified into: ascomycetes, basidiomycetes, and zygomycota .

In ascomycetes, the spores are produced within cells called asci, which vary in form from spherical to cylindrical. In general, each ascus holds eight spores. However that can vary from one spore per ascus to one hundred spores per ascus.

In basidiomycetes, the spores develop on projections, called sterigmata (singular sterigma), that grow out from cells called basida, which are elongated and club-like, although they too vary in shape. In general, each basidum has four projections and four spores, but, like the ascomycetes, these numbers also vary.

In zygomycota, the fungus dwells mostly in soil and decomposed dead matter. They reproduce in a somewhat unusual manner: finger-like outgrowths extend from each of the organisms and attach. Chemical signals determine whether the zygomycetes are compatible. If they are, the hyphae grow apart, but they double back and meet head on. The paired nuclei fuse and develop into zygosporangium, completing the cycle.



Boletes & poly pores
: Boletes are mushroom-like fungi, but with pores under the cap, whereas Poly pores vary from flat to mushroom-like fungi but also have pores.

Flask fungi:
These produce their fruiting bodies in small chambers.

Coral & jelly fungi
: Coral fungi are shaped like coral, while jelly fungi are feel like jelly.


Cup fungi
: In general, the cup fungi have fruiting bodies that are shaped like shallow cups or saucers
.

Stereoid & paint (or skin) fungi: Stereoid fungi vary from being mushroom-like to bracket-like, with a smooth underside. A paint fungus looks like an extra skin growing on the surface of some wood.

Stinkhorns, puffballs & birds nest fungi: Stinkhorn's are smelly, puffballs are powdery and birds nest fungi are shaped like cups with "eggs" inside.

Truffle-like fungi: Truffle-like fruiting bodies are generally out of sight, as in underground.
http://www.anbg.gov.au/fungi/types-of-fungi.html

Interactions

There are many different types of fungi, and each classification interacts with its community or its surrounding species differently.

As described in the plant-fungus interaction, some fungi are found to be mutualistic. A mutualistic fungus associates with another organism, usually with some benefits to both partners but always with benefits to the other organism. In a mutualistic associations, the benefits need not be equally shared. For example, the relationship between plants and fungi is mutualistic. Most plants rely on a symbiotic fungus to aid them in acquiring water and nutrients from the soil. Mycorrhizae, or "fungal roots" are the specialized roots which the plants grow and which the fungus inhabits. Since the fungus has such a large surface area, it is able to soak up water and nutrients over a large area and provide them to the plants. In return, the plant provides the fungus with energy-rich sugars produced through photosynthesis. This is an example of mutualism in which both species benefit from the interaction. Thus, the fungal roots serve as a symbiotic relationship between both plants and fungi.

Almost in contrast to these mutualistic fungi, there are also the parasitic fungi. The parasitic fungi obtain its nutrients from another living organism, with no benefit to the other organism. However, some parasitic species do not kill the organisms they feed on. There are also parasites with very specific host requirements and may only attack a single species, whereas others may parasitize hosts from a variety of genera. Thus, within this classification there are various variations.

However, not all fungi interact with a living species or organism. Such is the case for the saprotrophic fungi, which obtain their nutrients from dead organic matter, such as leaf litter, dung, soil, dead animals, wood, dead fungi, etc. Saprotrophic fungi feed on and recycle about 85% of the carbon from dead organic matter, while bacteria and animals are held responsible for the other 15%. These fungi release the locked-up nutrients that can then be used by other living organisms, making the fungi vital to the health of terrestrial and aquatic ecosystems around the world.

One of the many outcomes of the various interactions with fungi is disease. Many (but not all) cause several serious plant diseases. These fungi will in fact invade the plant cells. Other fungi may cause such human diseases as ringworms, vaginal infections where it is superficial, and athlete’s foot, just to name a few.

Importance

Many of the importance's of fungi are discussed in the other links of this web site. This is just to give an overview of some of the many importance's that fungi may offer. One of the major importance's of fungi is that fungi are known to breakdown organic matter and release nutrients back into the environment for reuse. Another importance of fungi is one of their main features of interaction. Many form mutualistic relationships with other organisms, such as lichens (fungus and green alga) and mycorrhizae (fungi and trees/plants).

Apart from fungi having an ecological importance in the world, they also have an economic one too. There is a certain importance of fungi involving food and beverages, such as the fact that yeast is used to ferment sugar to provide alcohol. Also, some of the unique flavors of certain cheeses (such as Bleu and Roquefort cheese) are produced from fungi. Mushrooms are also a very widely used type of fungus. There are also around 200 species of edible basidiomycetes.

Fungi also have a chemical importance in the economic world. For example, fungi help produce penicillin (one of the most widely used antibiotics) by producing deuteromycete pencillium. Also, as well as causing athlete’s foot and ringworm fungi, it also produces the antibiotic for them: griseofulvin. Furthermore, parasitic fungi do at least several million dollars of damage per year on crops.

 

 

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