As saprophytes (decomposers) are fungi ecological important in the degradation of plant material.
Fungi consist of cells with a nucleus, mitochondria and cytoskeleton. Among the fungi are unicellular as yeast as well as multicellular organisms such as fungi. The most striking part of multicellular fungi are not the underground hyphae, but above ground fruiting. The scientific research is called mycology. Often mushrooms are classified in parasites (profiteers), saprophytes  (cleaners) and symbiots (escorts, co-workers). In between, more and more overlaps are detected instead of strict separations. Symbiotes can often produce an enzyme that can degrade lingocellulose. They pass nitrogen (N) on trees, in exchange for carbon (C).

Fungi reproduce both sexually by spores and asexually (with hyphae and mycelia). Many fungi live in symbiosis with plants.
Fungi are useful for us in French cheeses (e.g. Brie, blue cheese) and mushrooms, antibiotics (e.g. penicillin).
But they also affect humans, animals, plants and homes. They were responsible for the potato famine in Ireland in 1845 and 1847. They are also feared as elm disease, ergot (Claviceps purpurea) on rye and wheat, scab (Venturia inaequalis) to include apple, and mildew (Erysiphaceae) on various plants.


Often they are detectable by their odor: musty, dusty, air of soil.
Avoid mold by keeping the area dry. Ventilate, avoid condensation.
Mold you better remove damp (water with vinegar or bleach) so you do not spread the spores. Wear gloves.
The spores in affected porous material (soil, food, wood) go beyond where you see them.

The Greek mycos means fungus, and Rhiza stands for root. On the operation and the use of mycorrhizal fungi really not much is known.
Under natural conditions, most plants cannot grow without mycorrhizal fungi.
Plants that not enter into symbiosis are found in the cabbage family (Cruciferae), goosefoot family (Chenopodiaceae) and mignonette family (Resedacea)), pioneer vegetation that seems to prepare for colonization by fungi.

Mycorrhizal fungi suffer a lot by eutrophication (fertilizer, excess nitrogen is supplied through the air), acidification, reduction of the groundwater by pumping, dehydration and fragmentation.
In farmlands fungi normally constitute 5 to 50% of the underground biomass and they ensure the uptake of difficult available nutrients. They also provide structure and stability, and even protect against disease agents and heavy metals. They bring water and nutrients. It is therefore a good bio - indicators of pollution, acidification, eutrophication and desiccation. Poor heath land cannot grow without the supply of food by symbiots. A balanced, stable soil with mycelium flakes needs (at least 45 to) 90 years to develop a full-fledged society. So you cannot just quickly "plant" a forest.

The hyphae form vast underground networks that connect plants and groups, and exchange materials. (Tree) roots secrete proteins. Mushrooms detect this and make contact, even impose themselves. There is a still largely unprecedented interaction with contact, fighting off, exchanging substances and competition between dozens of fungi (and roots) in the soil, in which other soil dwellers also play a role. A kind of internet or wood- wide-web. Some species we never see, they remain underground (or in wood etc.) Unlike most fruiting bodies (fungi or mushrooms) the mycelium can be years old. (Like a tree, with annual fruits.) In exchange for nutrients and water the plants provide sugars (carbon) to the mold. Studies with labeled C14 showed that they were transporting sugar from dominant plant species to weaker species. Nitrogen and phosphate are exchanged. Especially at a young stage it is important. Also, any mother trees in this way provide supply to their own seedlings. If a seedling quickly plugs into the network, thereby increases the chances on survival.

The wires of (ecto) mycorrhizal fungi grow both around and inside the root tips of (tree and plant) roots. If they form a specific structure between the cells at the outer edge of the root this is called the Hartig net.
In the formation of plant-fungus symbiosis both parties take into account a cost-benefit analysis.

Seeds of orchids are so small that they contain little reserve food (protein, sugar, fat). They are at the germination and initial growth, depending on carbon (of death, organic matter), which is provided by fungi.

Fungi increase the surface of which plants take nutrients with an estimated factor of 60. Fungi can (by separating (citric-, formic -or oxalic) acid) dissolve minerals. That way they make together with plant roots even traces in rock.

Daisy and ribwort plantain attract mycorrhizal fungi, and are therefore useful in the organic vegetable garden.

The usefulness and necessity of the presence of these fungi is why it is useful and sometimes necessary when sowing plants and planting trees also to take enough mother earth with. The land on which the mother plant was is aware of the beneficial fungi that so come along to the new environment. For example, to beech it is indispensable.

Plants that grow close to each other give underground signals that influence the growth of congeners.

The roots of maize plants separate chemicals that affect the growth strategy of their neighbors. Swedish researchers report this in the PLOS ONE magazine.

The scientists briefly touched the leaves of corn plants in the lab to simulate contact with a neighboring plant. Then they let other plants grow on the breeding ground of the misled plants. Those plants responded by producing more leaves.

'Touch is a sign for the plant to be a potential competitor,' explains Velemir Ninkovic (Swedish University of Agricultural Sciences). 'Since a plant can not move, it has to adjust its growth strategy. By producing more leaves, the plant can absorb more light and avoid shading by neighbors. '

Then the researchers gave corn plants the choice between a growing medium in which a touched plant had stood, and a medium in which a plant had been left alone. The roots usually grew in the direction of the untouched plant. So it seems that the plants are able to detect the difference.

Copper (Cu) is a well-known fungicide that kills fungi.

(See also <Plant breeding> and <Mushrooms>

Often mushrooms are classified in parasites (profiteers), saprophytes  (cleaners) and symbiots (escorts, co-workers). In between, more and more overlaps are detected instead of strict separations. Symbiotes can often produce an enzyme that can degrade lingocellulose. They pass nitrogen (N) on trees, in exchange for carbon (C).