drought and tree dieback How climate change is affecting fungi
Status: 01.09.2023 7:20 p.m
Drought, global warming, dying trees: fungi are affected by climate change in many ways. Some species are likely to disappear, new ones – including poisonous ones – are added. And the mushroom season is shifting.
If trees have problems, mushrooms also have problems – more and more mushroom experts in Germany are observing this. Because the fungi live in a close community with the trees. The underground network supplies the trees with nutrients, in return there are sugars for the fungi. This process is called mycorrhiza.
But if the tree is doing badly or even dying, this also has a major impact on the fungi. Saarland mushroom expert Harry Regin observes this in spruce. More and more trees are dying due to drought and drought. Large parts of south-west Germany and other areas such as in the Harz mountains and in east Germany are affected. This means that fungus species such as the spruce irritant are having an increasingly difficult time.
Winner and Loser
The mushroom expert has observed that after the tree dies, there is a kind of mushroom explosion. Many fruiting bodies form for a year or two. This also creates many spores that are carried further with the wind. In this way, the spores can find a new tree with which the fungus can continue to live in symbiosis. A system that usually works.
However, due to the recent drought, the system is out of balance: Because many spruce trees are currently suffering from severe stress and are being decimated, the spores cannot find a new tree. This means: Without this partner, the fungus can die out in the region in which it has lived so far.
But there are not only losers, but also winners from climate change. This is especially true for species that specialize in deadwood. Take the giant polypore, for example: it tolerates rising temperatures well – and since more trees are dying as a result of climate change, it can spread more easily. After all, there is enough deadwood from which it can draw enough nutrients.
The drought of recent years has damaged the forests – and with it the mushrooms.
New species of fungi are migrating to Germany
The German Society for Mycology, i.e. the German Mushroom Society, observes that there are also climate immigrants among fungi. Species that otherwise grow in the Mediterranean region or south of the Alps have now also gained a foothold north of the Alps. As an additional edible mushroom, the Kaiserling can be found in some places in Baden-Württemberg, Hesse, Rhineland-Palatinate and Saarland.
But not only the edible immigrants are on the rise – the same applies to poisonous species such as the false meadow mushroom. It is very similar to the edible mushroom and can cause stomach and intestinal problems.
Climate change extends mushroom season
The early start of the mushrooms this year was due to the wet and warm weather. But the trend is going in the other direction. Although heat and drought are increasingly delaying the start of summer in the mushroom season, the mushrooms can be collected longer. The reason: the mushrooms only grow when there is the right mixture of moisture and warmth.
This is why the fruiting bodies sprout vigorously more often in late autumn. However, the mild temperatures mean that you can still pick mushrooms in November. For example, the oyster mushroom or chestnut boletus and the porcini mushroom.
mushrooms as carbon storage
But the fungi are not only victims of climate change – they also seem to play a major role in the fight against it. A study by the University of Cape Town comes to the conclusion that root fungi store a large amount of CO2: the equivalent of more than 35 percent of annual CO2 emissions from traffic. The scientists therefore come to the conclusion that the influence of the fungi on the climate and climate change has so far been underestimated.