2017

What do We Know about Mushrooms - "Tree-eaters"?

It's been a long time since the mushroom season in Latvia has come to an end this year. This, however, does not mean that the mushroom time is over. Every year, a number of mushrooms may be spotted until the first permanent snow, and some of them even longer. The majority of bracket-fungi seem to completely ignore the calendar.

Mushrooms are neither plants, nor animals, but a state of individual organisms - fungi. Dead wood residues are mostly degraded by toadstools. Several species of toadstools, working hand in hand with micro-organisms or successively replacing each other, contribute to the decomposition of dead wood, causing its decay. The process of decay continues also when dead wood remains hidden under the moss deck. The process ends only when the decaying trees have become part of the soil.

The main ecological task of fungi - degradation of dead wood - is most visibly performed by bracket-fungi (polypore mushrooms). A total of about 150 species of bracket-fungi are to be found in Latvia. Usually their carpophores (fruit bodies) are annual and grow mainly on dead wood. There are not many parasitic species, the mycelium of which grows on growing trees; parasitic species account for only about one fifth of the total number of bracket-fungi species that may be found in Latvia. These species are mostly perennial, relatively tough and hard. For example, the relatively well-known chaga mushroom, which lives on birch trees and is considered to be curative, should be mentioned here.

There is a broad variety of bracket-fungi such as Phellinus, Oligoporus placenta, Ganoderma, Polyporus obliquus, Fomitopsi, Lenzites betulina, Trametes, Gloeophyllum sepiarium, Oxyporus corticola, Polyporus, and many others. The red belt conk (Fomitopsis pinicola) is among the most common bracket-fungi in Latvia. It grows both on fallen deciduous trees and coniferous trees, as well as on decaying tree trunks. Often the tinder polypore (Fomes fomentarius) may be spotted on decaying deciduous trees. It is a long-life fungus, loved by insects. The birch mazegil (Trametes betulina) is fairly common on wood of dead deciduous trees - it is an annual and relatively small fungus. In turn, the dryad's saddle (Polyporus squamosu), which grows in groups both on living and dead deciduous tree wood, is huge compared to any other fungi - its diameter can exceed half a metre. Also the yellowish sulphur shelf (Laetiporus sulphureus) like both living, as well as dead trees. The grifola umbellata, in turn, is a very specific, rare and protected fungus in Latvia.

The jelly-like tremella often parasite on Gloeoporus taxicola and may be spotted in different seasons of the year. The yellow brain fungus (Tremella mesenterica) may be seen on deciduous trees. The Tremella foliacea also grows on both deciduous trees and coniferous trees, but it is less common.

The scrambled egg slime (Fuligo septica) is another strikingly yellow, often occurring formation that belongs to the Mycetozoa group. Several dozen Mycetozoa species have been found in Latvia. They are characterized by the fact that, even within one species, and during the lifetime of one specimen, mushrooms tend to have a variety of shapes and colours, and they are able to move.

Honey fungi, or Armillaria, are a group of fungi that mainly grow on tree stumps or in their close vicinity. The fruit bodies of these small fungi are usually arranged in dense clusters or large groups. The Flammulina velutipes can be seen throughout the year on trunks and strains of both dead and living deciduous trees. In turn, the honey fungi are parasitic, since they live on organic matter of living trees.

The fairy inkcap (Coprinus disseminatus) grows in larger groups. However, it does not belong to the coprinus genus, and does not produce ink when ageing. Groups of these small fungi choose to live next to tree stumps or on tree trunks.

Of the six species of gasteromycetes to be found in Latvia, two species are important for wood processing. The common pufball is one of them. These mushrooms may be spotted in different places of a forest, growing in soil or on decaying wood.

Stump puffballs are no less common. Their carpophores grow in groups next to tree stumps, on decaying wood, mossy and fallen tree trunks. The tubers of these mushrooms are most commonly found in autumn, but if they are not trapped under the feet of animals or people, full of spores they can survive until the next spring.

Spores of mushrooms cannot penetrate an undamaged whole tree bark; therefore, they must land on a dead tree or at least a damaged tree. There are so many spores in nature that some get lucky. Taking a walk in a forest, people often will find that several species of spores have fallen into the same wood and each has created its own mycelium.

It is important to protect all the mushrooms – not only those that seem attractive to us. The forest needs them - a natural forest without these wood-decaying organisms would not be able to survive!