"20 years from now, the current fires may seem like a warm-up." What science has to say about forest fires and what the correct approaches to combating them are

Northern forests will never stop burning, it is a natural part of their life cycle. Scientists urge that we have to switch the attention of the public and the authorities from extinguishing each fire to controlled arson and sanitary deforestation.

While in Russia and Yakutia people are trying to explain the causes of unprecedented forest fires and find someone responsible for them, scientists are trying to warn the world community against even more terrifying fires. This follows from a recent article on the Russian popular science portal Naked.Science, in which journalist Alexander Berezin analyzed scientific research on this topic. Journalist of News.Ykt.Ru talked with its author about the significance of forest fires, their scale and scientifically correct methods of combating them.

If there are no forest fires, there will be no taiga

Living in the North is not easy not only for people, but also for trees. To grow, the northern forests need fires. This is a fact proven by scientists. Alexander Berezin explains it by the example of larch. According to him, scientific work has long shown that the life cycle of this higher plant between forest fires lasts about 80 years.

The yagelnik in the northern forest works as an excellent heat insulator. Until it burns out, the summer heat almost does not warm up the permafrost, and it comes gradually. Source: wikipedia

The growth cycle of larch. Source: ©Anastasia A. Knorre et al.

"At the beginning of the cycle, after a fire, a layer of mosses (or a yagelnik) burns out, the permafrost retreats 1.5-2 meters deep, trees begin to actively absorb nutrients from the soil and grow rapidly. After 20-30 years, the thickness of the permafrost-free soil layer narrows to a meter or half a meter. At this moment, already quite large tree crowns shade the earth from the sun's rays and permafrost continues to "squeeze" the roots of plants. After 70-80 years, the roots of plants remain only 20-30 cm. This is literally the limit of survival for trees in the taiga. When the permafrost rises higher, the trees do not receive the necessary amount of nutrients, begin to wither and become an easy prey for fires. The fire thaws the permafrost again and the cycle starts again," says Alexander Berezin.

By the way, larch stands for 35% of the area of all Russian forests and at least 70% of Yakut forests. Accordingly, the Yakut taiga will not stop burning.

In addition, as scientists note, there is a cycle of chemicals in any ecosystem. Trees absorb carbon dioxide (CO2) from the air, phosphorus and nitrogen from the soil. After death, they return them back, but in the North this process is difficult due to the cold and dry climate, as well as due to the absence of termites and fungi, which in warmer climates help to recycle dead trunks and stumps. Without this process of returning nutrients, the growth of new trees is difficult, so fires come to the aid of the forest.

"Trees photosynthesize at the expense of leaves. Chlorophyll and some other compounds in them simply cannot be built without nitrogen and phosphorus. The further to the north, the less phosphorus is returned to the soil. Without the return of these substances there, it is difficult for new plants to develop. But in the forest tundra, the trunks of dead trees can lie for decades without decomposing. But lichens, yagelnik, which require a small amount of trace elements, can grow. Instead of insects and fungi, dead trees in the taiga are destroyed by forest fires," the journalist explains.

In addition, small seeds of coniferous trees after falling out of their cones can remain on the moss without giving roots. The seeds simply do not reach the soil, which is why they cannot germinate. A grassroots fire cleanses the forest of moss, without destroying trees with thick bark.

As Alexander Berezin notes, if you look at the photos of the taiga, where there have been no fires for 300-400 years, you can see that many trees have already died, individual larches are in a state of painful twisting, and most importantly, new trees do not grow.

How badly did Russia's forests suffer from the fires of 2021?

In our country there are only officially 809 million hectares of forest. These figures are actually underestimated, scientists say. Taking into account abandoned agricultural lands overgrown with new trees, and some other categories, they account for 1.1 billion hectares of forest in Russia.

Yakut forests cover more than 80% of the territory of the republic. According to the regional government, the forest area of Yakutia is about 240 million hectares.

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In 2021, 17 million hectares of forest were burned in Russia, of which only in Yakutia more than 6.6 million hectares burned down.

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"If you look at the scale of fires in hectares, the figures are impressive. If we take it as a percentage of the total area of forests, then this is not such a large scale. 2% of the total area of forests in Russia has been passed by fire, which is quite a rare phenomenon that happens on peaks. That is, it is a very small part of all the forests. In addition, it is important to remember that about half of the forest passed by fire does not die, but survives," notes Alexander Berezin.

It is impossible to say that there are more forest fires than 100-200 years ago, there is simply no such data.

"The main area of forest fires in our country belongs to the northern, taiga forests. Just to those where there is the least population, where fires are burned less often and where the chances of anthropogenic ignition are the least. Whether there is a long-term increase in fires here is a very difficult question. 200 years ago, there was no monitoring from satellites, and there were problems with dense population. The peak fires of 1915 were definitely larger than any fire of the XXI century, but there is no complete understanding of the average area of fires per year," the article on Naked.Science reports.

If we look back at a larger historical period, then in the past, especially during warm periods, there were more fires than today, the author of the article notes. This is evidenced by scientific studies on the amount of charcoal that remains after forest fires in fossil layers over the past thousand years.

As Alexander Berezin notes, since there have always been fires in the taiga, then the local fauna has a huge experience of surviving a fire. We should not expect the extinction of individual species or a decrease in biodiversity due to forest fires.

According to the conclusions of scientists, the frequency of forest fires will inevitably increase in the future. The larger the taiga, the more it needs the fires.

There are more and more forests

While the media and Greenpeace are sounding the alarm that forests are burning and being cut down, scientists are discussing that there are more trees.

According to a study by Russian scientists published in Scientific Reports in July 2021, forest biomass increased by 39% between 1988 and 2014.

"In this article we are talking about huge quantities. It turns out that the increase (excluding dying trees) of forest biomass in Russia exceeded three tons per person annually. This will sound quite unusual for those who are used to listening to the news from the TV, but from there you will not hear scientific news. As a result, it turns out that the average person is disconnected from what is really happening," notes Alexander Berezin.

According to him, satellite maps, which have been conducted since the early 80s, also show the growth of plants all over the planet. The main reason for this phenomenon is the annual increase in the amount of carbon dioxide in the air. CO2 is the main food of plants.

According to the observations of Russian scientists, in Yakutia, the taiga is moving north to where the tundra is now. This is a natural process with global warming.

"Four to nine thousand years ago, when the climate was much warmer, there was no tundra on the coast of the Arctic Ocean (there was an article about this in Quaternary Research), there was a forest of birches and larches. Until now, stumps from that taiga can be found in this territory up to the very lower reaches of the Lena. In Yakutia, over the past decade, the forest has shifted to the north by literally several tens of kilometers. In the foreseeable future, the situation will return to that, and there will be no tundra at all. But, of course, it won't happen now," says Alexander Berezin.

On the one hand, the increase in the volume of forest resources is a positive thing, but on the other hand, it is a problem, the journalist notes. According to him, the Russian economy will not be able to process as much wood biomass as it grows.

Deforestation in Russia is recorded at a level of less than 250 million cubic meters of wood per year. At the same time, according to an article in Scientific Reports, forest biomass in Russia increases by more than 1 billion cubic meters annually. That is, the volume of deforestation is four times less than the volume of forest that grows every year.

"This is not because our timber industry cares about nature, it's just that the main growth of forests occurs in very remote places, from where it is too expensive to export wood. Where there are roads, people cut down the trees a lot, but the infrastructure in the country is undeveloped, so the bigger part of forests, more than three-quarters, of the increase is not used by anyone. As a result, all this may become a serious problem in the future, because the forest that grows, but is not used, eventually becomes fuel for future fires. Russian scientists regularly talk about this, for example, Vyacheslav Haruk, Doctor of Biological Sciences from the V.N. Sukachev Forest Institute of the Siberian Branch of the Russian Academy of Sciences," the Naked Science journalist emphasizes.

What should people do?

What has a beneficial effect on nature can be detrimental to people. It would seem that what is wrong with the growth of forests all over the planet? According to scientists' forecasts, an increase in the area of the taiga will be followed by an increase in the number and scale of forest fires. But it is not worth fighting every small fire away from populated areas. This is explained not only by the inexpediency and high cost of such measures, but also by the harm to the ecosystem.

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Why is it not necessary to extinguish every small forest fire? Learning from the mistakes of the USA

This conclusion was made by scientists after analyzing the fight against fires in the United States, where at the beginning of the twentieth century they began to actively fight forest fires, each time suppressing small ones.

As a result, after decades, part of the forests of America turned into "stagnant ones". In such forests there are a lot of dead trees, dead wood, and coniferous litter. All this turned into "fuel" for new, more powerful fires. By the end of the last century, fires in the United States had acquired a terrifying scale. At the beginning of the XXI century, we can observe the same situation in California.

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In 2015, in the journal Science, a group of American scientists published an article "Reform forest fire management". In that article, they called on the US authorities to put into practice the so-called prescribed burning (or controlled burning) to clear forests from old trees.

Prescribed burning is a controlled arson, which is carried out by firefighters in order to avoid a larger fire. This method of reducing the threat of forest fires is also suitable for remote areas of the taiga, where sanitary deforestation will be impractical. It is proposed to conduct them in the forests in strips. If the flames flare up, then the fire will not be able to jump over the already scorched territory. In this way, you can control the scale of fires.

"As a doctor prescribes medicine, firefighters can also "prescribe" this procedure to a particular forest if necessary. It is proposed to conduct them annually in the spring, when the surface layer of the soil is still quite cold and relatively moist and burns with difficulty, that is, the fire will not spread further. The idea is still being promoted in Canada, but in the USA it is difficult, it is not used very often in practice," says Alexander Berezin.

Do not confuse this concept with the burning of grass. Alexander Berezin emphasizes that the burning of grass outside the forests is harmful to the ecosystem.

"Plants outside the northern forests do not require systematic burning. This does not happen in nature, unlike in the taiga. In addition, agricultural waste reduces biodiversity. Controlled burning from agricultural waste differs in that it is carried out by professionals in forests. In the middle part, this is irrational. Burning is relevant only where fires are a natural part of the forest growth cycle, that is, in the northern taiga," he says.

In Canada, this method is already being used. A forest protection officer with the help of special equipment sets fire to the strip, immediately followed by a group of firefighters with extinguishing media. Vegetation is slowly burned out by the grassroots fire. If the fire goes to the side, it is immediately extinguished.

In order not to repeat the tragedy of the village of Byas-Kyuel, scientists recommend sanitary deforestation around settlements and controlled burning, which can reduce the scale of forest fires.

In addition to burning, scientists also propose to protect cities and villages from forest fires with the help of sanitary deforestation. In addition, such a "fire barrier" can also be created in a forest area (if it is not located in hard-to-reach places). According to Alexander Berezin, these measures can reduce the risk of particularly large fires that make the air in populated areas dangerous to health.

"An article in Science of 2015 notes that a zone of at least 60 meters without trees should be created around all settlements, otherwise the threat to settlements will be too great. This is the minimum distance that will protect from a grassroots fire. But thinning the forests away from populated areas is an unrealistic approach. The volume of forests in our country is so large that we do not have enough people to thin out forests from old trees, as they do in Finland," the journalist believes.

So far, sanitary deforestation and controlled arson are mainly the proposals of scientists, but not a widely used practice. According to Alexander Berezin, since in the USA, where they had previously encountered this problem, these measures are being implemented slowly and reluctantly, it is doubtful that in the near future these measures will enter the arsenal of the Russian forest protection.

"The huge problem is that the media and the Russian Greenpeace believe that it is necessary to extinguish any fire always and everywhere. They do not know that because of this, fires will be stronger in the future. If the public does not have this awareness, then the authorities do not know anything about it, although scientists write about it all the time. But who reads scientific journals?", Alexander Berezin laments.

Photo on the main page: Ivan Nikiforov

Author: Ksenia Gabysheva