! Rainforest Fungi ! Tropical Rainforest, Far North Queensland Australia

Rainforest Fungi
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Fungi Information

Feeding

They do not photosynthesise, but have an external digestion method.
Fungi are heterotrophic (they do not produce their own energy like plants) and obtain energy from complex food, like dead or living plants and animal tissue.
In the rainforest, several types of fungi may be seen sprouting from a single log. It is quite hard to believe that when a few tiny fungi are seen sprouting from a huge log, they are actually digesting it. It is a contest that appears unequal, but in the end, the fungi will always prevail. They have recycled for hundreds of millions of years.
Water is essential, as some fungi need it to inflate their cells to keep their form, especially in umbrella-shaped fungi like mushrooms and toadstools.
Bracket fungi are made of stronger material so do not need water for their structure.
However to grow, they need a high moisture level in the wood they digest.

Decomposers

Fungi are the great decomposers and recyclers of nature.
When a tree grows, nutrients such as nitrogen and phosphorus accumulate. After the tree dies, it must decompose before these nutrients become available for other plants.
Fungi are most important as they are able to degrade lignin (the most durable component in wood). Lignin is the material that gives wood its strength. It is a three-dimensional polymer comprising of sub-units joined by a variety of chemical linkages, which are difficult to dismantle. Specific fungi (eg bracket fungi) are designed to do this job, and once they have started, other fungi will follow.
Fungi hair-like filaments invade dead plant matter, and are sometimes parasitic on tree roots.
By breaking down organic material so plants can re-use the nutrients, fungi help rainforests to grow on very poor soil.
This makes fungi ecologically vital, particularly to rainforest communities
Just about every square centimetre of rainforest soil has fungi filaments.
All fungi contribute to the welfare of the forest, no matter how big or small they are.

Transporting Nutrients:

Fungi transfer nutrients via a structure called a mycorrhiza.
The fungal threads form a sheath around the root before penetrating between the root cells.
The fungi receive vitamins, simple proteins and sugars from the tree in exchange.
As a common practice in commercial forestry, seedlings are now grown with an appropriate fungus, as plants with mycorrhizal fungi have been found to grow much faster than plants without them.

Relationships with other Organisms:

Most fungi are closely associated with dead or living plants, and sometimes with animals.
Saptrotrophs – these types of fungi break down animal and plant remains so nutrients can be released and taken up by new living plants and animals (recycling of nutrients).
Parasites – these types attack living tissues and divert their resources to their own use. They produce fruiting bodies on living hosts.
Mutualists – these fungi digest wood to help other rainforest beings (eg. insects) and help feed released nutrients back into growing trees.

Reproduction:

They are able to reproduce by producing spores (most mushrooms only live long enough to distribute their load of spores).
The fruiting bodies of many fungi have delicate gills through which these spores are discharged.
They do not have a flowering stage.

The Fruiting Bodies:

It is the fruiting body (reproductive organs) of fungi that we know as mushrooms, toadstools, bracket fungi and puff-balls.
Rainforest fungi may have dazzling colours and bizarre shapes.
Slugs, snails, cassowaries, rat kangaroos and insects feed on fungi but many brightly coloured species are poisonous to people and other animals.
The incredible stinkhorns are foul smelling, net covered fungi that pop-up after heavy rain.
Some mushrooms and fungi are able to glow in the dark (called bioluminescence). This is due to a chemical in the fungus that reacts with oxygen – the same process as in fireflies. In the Atherton Region there is one such mushroom. It is a very small blue-green glowing cap only 3-5mm in diameter, and is commonly seen on the forest floor.
Fungi are a very visible part of bushland scenery, particularly in wet seasons.

Biodiversity:

There is a very vast range of fungi, with more biodiversity than in the plant kingdom, and possibly more than in the animal kingdom.
Fungi share similarities with both plants and animals.
Characteristics in common with animals include having chitin in their cell walls like in the exoskeletons of insects, and using glycogen (not starch like plants) as a storage component.
Their reproductive processes are like plants however, as they shed spores like mosses and ferns.
Scientists from the USA and Canada suggest that some fungi should be classed among the biggest and oldest organisms in the world.
One individual fungus of the species Armillaria bulbosa takes up an area of 15 hectares. It is estimated to weigh about 100 tonnes (the same as an adult blue whale), and to be over 1500 years old. DNA tests were used to obtain these figures.
They were previously classified as the fifth kingdom, but now this has been split up into two or three kingdoms.
They are characterised by two different types of cells – tubular (hyphal) or elliptical (yeast) cells.

The Role of Fungi as Food:

Macrofungi fruiting bodies (mushrooms) are eaten by many animals of all sizes.
Underground fruiting bodies (truffles) rely on animals to dig them up (eg. bettongs).
They can be used to make alcohol, bread, cheese and soy.
Some are psychedelic.
Some are very toxic.
People must be careful to identify mushrooms before eating them.
The potato blight fungus caused the great famine of Ireland in the mid-19^th Century.
Rust and smut fungi attack grains (eg wheat and rice).

Additional Information: Courtesy Of Damon Ramsey

While their form and pace of life are obviously plant-like, they do not photosynthesise, but actually ingest food as animals do.
There are thought to be about 250,000 species of fungi in Australia, and thus they far outnumber the regular vascular plants. However. most of these species are too small to be noticed, with only about 5% of fungi produce fruiting bodies that are large enough to be seen by humans.
Identification and taxonomy of fungi is a fairly obscure and specialist task, and many groups are thankfully named obviously and simply for their shape and design of these reproductive structures.

Script: Courtesy of Damon Ramsey BSc.(Zool) Biologist Guide