HS Environment HS checked the facts: Forest fires and logging create a similar situation, said Minister Leppä – the claim is not true

Policy|HS Environment

I– and the Minister for Forestry Jari Leppä (kesk) said in Yle’s story on Wednesday:

“When nature burns a forest, for example, it causes a similar situation. Still, that forest is regenerating there. ”

this was Yle’s thing Alder’s comment on logging and the fact that logging can reduce the number of species.

Alder’s claim about the similar effects of forest fire and logging is false. There is research data on the effects of forest fires, which says that Lepp’s claim is not true.

In this case, the claim is reviewed by dismantling it and telling what is known from the study.

Let’s get started from the first part of the first sentence: “when nature, for example, burns the forest”.

Nature does not burn the forest so unequivocally.

Finland’s climate is semi-maritime and humid. It curbs fires here, while in continental climates like North America or Siberia, fires can be more severe.

In addition, in Finland, bogs and smaller and larger water bodies divide forests, which prevents the spread of fires.

So a forest fire usually stays small, a few hectares in size.

In addition both living trees and decaying trees and other forest material lying on the ground are often damp. There is relatively little combustible material in the forest. In a forest fire, the coils and the litter, the dry surface of the humus and the layer of moss and sparrows usually burn.

So often a forest fire is not a raging Fire Storm but practically a surface run-off running along the land.

There must be exceptionally dry and windy conditions for a forest fire to escalate into a severe head fire.

Spruces ignite more easily, but pines in particular can withstand fire well because they have a thick bark.

So nature rarely burns woodland In Finland, even if it could burn or burn some forest or forest floor. Forest fires are not as devastating as Leppä Yle says.

Research articles have been written about forest fires, for example, Timo Kuuluvainen, Heidi Tanskanen, Markku Larjavaara, Tuomo Wallenius, Juho Pennanen, Jouni Kouki, Aki Pitkänen, Pertti Huttunen, Kimmo Tolonen and Ari Venäläinen. The matter is reviewed in research, for example in a book Finnish primeval forest, which the Member has been doing.

Next the last part of the sentence: “it creates a similar situation [kuin hakkuut]”.

Alder or Yle does not specify what kind of felling is being talked about. Usually, the felling discussion related to the nature roof focuses on the forest grown at an equal age and its final felling. This is also more common than the way of continuous education. It is therefore assumed that this is final felling, which results in a logging opening in the forest.

Felling means that the trees are felled and then the trunks are removed. After that, it is usually time to regenerate the forest. It often means treating the soil in some way, such as by patching. In addition, forestry machines otherwise break the ground when collecting trees.

Now connect both sides of the sentence, ie whether the situation after the forest fire and the final felling is similar.

In felling, the trees die, in addition to which they are removed. In a typical forest fire, a large part of the trees survive, in addition to which damaged trunks and other burnt forest material remain in the area.

Even if the fire is severe, a Finnish forest fire typically burns about a third of the surface wood. Most remain in the woods.

In addition, burnt wood provides a lot of habitat for different species. Some beetles are dependent on forest fires. They can detect smoke and heat from tens of kilometers with their infrared sensors. Their females lay eggs on charred trees, still warm after the fire.

The situation after a forest fire is therefore very different from that after logging.

Read more: A huge forest fire erupted in Lieksa in 1992, and it began with an astonishing account of nature’s own recovery – “What destruction is this?”

Sentence in addition to the parts, it is also possible to assess whether the idea is relevant at all. Does equating forest fire and logging make sense or make sense? This can be judged by the occurrence of both: whether they are parallel, i.e., real alternatives to each other.

Timo Kuuluvainen and Tuomas Aakala have gone through 43 studies dealing with natural forests. Their

their research article

according to the typical disturbances in natural forests are windfall, surface damage, insect pests and other so-called small-hole dynamics. They kill by killing individual trees or small groups of trees.

Thus, large forest fires are not typical.

EnlargeHowever, forest fires are the most important disturbance compared to logging.

Forest fires have occurred in Finland naturally every 200–500 years. For more information, see from 2002 or from 2005 existing studies. In addition, the work

Northern forests – research results for ecological forestry

says that the burning interval in the pine forests of northern Finland has been 350 years.

During the growing season, the forests burned frequently, but that was not the natural burn interval of the forests. Back then, fires were man-made, as were logging.

Depending on the place of growth, the forest can be felled every 80 years. It is a much faster pace than a natural forest fire that recurs every 200 to 500 years. Comparing forest fires and final felling is therefore not very meaningful. One rarely encounters the forest, the other repeatedly.