For a long time it was believed that witches or the devil played a role in the appearance of mushrooms. You cannot see how they arise. Now we know better. Mushrooms are the fruiting bodies of fungi and arise from fungal threads (mycelium) that grow in the soil, between leaves or in wood. More mushrooms can grow each year from the small mushroom buds on the edge of the mycelium. Humidity and (micro)climate must be perfectly fine. This is often the case in autumn, which is why you see so many mushrooms. Fungi reproduce by spores. One track is small and cannot be seen; a whole bunch of spores together form a kind of powder. The spores are usually spread via the wind, but sometimes also because the fungus actively catapults them, or via insects.
Cleanup is nice
Skovrider Evert Thomas: “Mushrooms are essential for the ecosystem. They can clear waste and serve as food for animals and humans.” One can talk about a triple function of fungi. Saprophytes are the group of fungi that break down decaying organic matter and dead wood and convert them into minerals and plant nutrients. For example the red spruce only grows on the needles of the Norway spruce and the pine cone fungus only grows on its fallen cones.
Then you have the parasites; these fungi draw nutrients from their host and often occur on living organisms that are already in a poor state. Native oak trees, for example, are susceptible to honey fungus. If an oak is infected, the tree often dies in the long run. The dead wood becomes softer and thus serves as a living and birthing place for countless animals.
Give a little, take a little
Finally, the symbiotes live in harmony with their host. “These fungi connect with tree roots to exchange substances. The so-called ectomycorrhizal fungi occur in areas that are naturally low in nutrients. Thanks to these fungi, trees get sufficient nutrients and water so that they can survive better. As a reward, the trees give sugar to the fungi. Real bartering, therefore,” says Evert. An example of a symbiote is the rather rare dark purple curtain fungus. In chalky coniferous forest, he trades with pines and firs.
If there is already a lot of nitrogen (and therefore food) in the soil, trees do not need ectomycorrhizal fungi. They then release less sugar, causing these fungi to disappear. But the trees also have a problem with that: without fungi it is more difficult for them to survive periods of drought. In addition, some fungi play a role in obtaining phosphate and water or in protecting against heavy metals. Because of their sensitivity to nitrogen and other soil properties, fungi provide a good picture of the state of the soil. Evert: “In the heart of Drenthe, the traditionally lean sandy soil is very suitable for chanterelles. With the increase of nitrogen in the air and its precipitation in the soil, the number of chanterelles decreased and poor areas quickly became rough. If we do nothing, it will soon be overrun with nettles, blackberries and liverworts, species that thrive on too much nitrogen. To restore and increase biodiversity, we must first undo the human interventions that disrupt natural processes. For example, we will fill dug ditches and let the low parts of the forest become swamp forest through rehydration. Felling is also carried out in planted production forests with predominantly conifers to make room for natural regeneration of deciduous trees. After that, we can let nature run wild again,” explains Evert.
The Scandinavian ecosystem in Drenthe’s old dense spruce forests is quite special. The fir trees planted here in the last century were able to grow into an impressive forest thanks to the cooler and wetter climate. “It turned out to be the perfect conditions for many different types of mushrooms. Even for very rare species. Therefore, together with the Drenthe mushroom working group, we have decided to designate the three Norway spruce forests with the most mushrooms as reserves and to cut down at least nineteen other forests,” explains Evert. “This also gives very special mushrooms more space.”
Text and photos: Staatsbosbeheer