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.

beschimmeldepaddenstoelFungi 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.
The hyphae form vast underground networks that connect plants and groups, and exchange materials. A kind of internet or wood- wide-web. 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.

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

(See also <Plant breeding> and <Mushrooms>