And over the city – a new smoke. Expert on the causes and nature of forest fires

Forest fires in the country blaze every summer, but residents of large cities notice them only when the streets begin to tighten with haze and it becomes increasingly difficult to breathe. This is the situation now. 

The chief researcher of the Center for Problems of Ecology and Forest Productivity of the Russian Academy of Sciences, Deputy Dmitry Zamolodchikov, Editor-in-Chief of the “Forest Science” journal, Doctor of Biological Sciences.

A field or a meadow can burn

Aif.ru: — How often do forest fires occur?

Dmitry Zamolodchikov: — It depends on regional conditions. Firstly, on how often adverse weather events occur, associated with the formation of heat and dryness over a long period. Secondly, on what kind of forest grows there and how easily it ignites. In different regions of our country, these periods can be both short (from 3 to 10 years) and long (take tens or even hundreds of years).

— Let's take the Ryazan region, where the forests are now burning. 

— In it, as in other regions of Central Russia, the frequency of severe fire hazard situations is approximately 15-20 years. 

Forest fires in the Ryazan region

© Andrey Abakumov

© Andrey Abakumov

© Andrey Abakumov

© Andrey Abakumov

© Andrey Abakumov

© Andrey Abakumov

© Andrey Abakumov

© EMERCOM of Russia for the Ryazan Region

© EMERCOM of Russia for the Ryazan Region

© EMERCOM of Russia for the Ryazan Region

© EMERCOM of Russia for the Ryazan Region

© EMERCOM of Russia for the Ryazan Region

© EMERCOM of Russia for the Ryazan Region

© EMERCOM of Russia for the Ryazan region

Forest fires in the Ryazan region

© Andrey Abakumov

© Andrey Abakumov

© Andrey Abakumov

© Andrey Abakumov

© Andrey Abakumov

© Andrey Abakumov

© Andrey Abakumov

© EMERCOM of Russia for the Ryazan Region

© EMERCOM of Russia for the Ryazan Region

© Main Directorate of the Ministry of Emergency Situations of Russia for the Ryazan Region

© EMERCOM of Russia for the Ryazan Region

© EMERCOM of Russia for the Ryazan Region

© Main Directorate of the Ministry of Emergency Situations of Russia for the Ryazan Region

© GU EMERCOM of Russia for the Ryazan Region

— Now every summer is hot and dry. What determines whether a fire breaks out or not? 

— It depends on a complex of reasons, but weather factors still come first. A severe fire situation is observed when there is a high temperature and no precipitation, and this lasts a very long time, plus the wind plays a big role, which spreads the fire. In this case, the probability of a forest fire is high, and as soon as a cause for ignition appears, it arises and develops further and further.

And the cause for ignition is human activity, one way or another connected with fire. It can be an agricultural fire, a match or a cigarette butt thrown in the forest, an unextinguished fire.

If the summer is hot, but it rains from time to time, there will be no forest fire.

— Also, it probably won't exist if everything in this place has already burned down a year ago?

— But this is not a fact. A natural fire can develop not only in the forest, but also in the field and in the meadow. When the forest burns down and the tree stand dies, the next year the vegetation cover resumes — grasses and shrubs begin to grow there. And after a few years, quite dense vegetation is formed. And it can also catch fire, although the scale of such a fire will be smaller and it will be easier to deal with it.

— Is it possible to fight forest fires by causing rain artificially? After all, the technology has long been worked out and is used to “disperse the clouds”, for example, before the parade on May 9.

— Last year, catastrophic fires raged in Siberia, which forced the authorities and the scientific community to look for new ways to solve the problem. Calling artificial rain — just one of them. In some regions of Yakutia, this method was already used last summer, and it seems to have had a positive effect: the scale of fires has decreased. 

Since this year, a large project has been implemented in Yakutia, in which Rosleskhoz, the Ministry of Natural Resources, and the Russian Academy of Sciences are participating. Its purpose — Learn how to make artificial rain. That is, the technology is being perfected, but we must understand that it is not a panacea. Artificial rain can be caused only where there are resource clouds, that is, clouds into which reagents (primarily silver compounds) can be introduced to form centers of moisture condensation. Then the water will spill. If there is such a powerful anticyclone that there is not a single cloud in the sky, it is useless to call rain. There simply isn't enough moisture in the atmosphere. 

There are more and more people, the temperature is getting higher

— Scientists from the Institute of Geography of the Russian Academy of Sciences conducted a study and found that over the past thousand years, forest fires began to occur 2-3 times more often. Why do you think?

— Because over the past thousand years, the number of people has grown many times over. There are almost 8 billion of us now. Imagine how much more bonfires there were than there were in Viking times. 

Of course, there is another reason — climate change, they have become apparent over the past hundred years. It is now known that as temperatures rise, extreme weather events, including heatwaves, are on the rise. There are more so-called blocking anticyclones when hot and dry weather persists for several weeks. Therefore, fire hazard situations began to arise more often.

— There is an opinion that fires benefit nature — they remove dead dry trees, renew the forest. Is that right?

— The question is complex, and there is no clear answer to it. For example, some scientists believe that larch forests in the same Yakutia (frozen larch forests) are pyrogenic, that is, “fire-loving”. Fires are a necessary condition for their existence, since they provide them with the necessary substances. As we know, there are very cold winters and dry summers in those parts. Under such conditions, dead organic matter — fallen needles, leaves, twigs — practically does not decompose. How to return nitrogen and phosphorus to the biogeochemical cycle? Nature does this through fire. For several years, dead organic matter accumulates in the forest, then a ground fire passes, and it burns out, while the larches themselves survive.

On the other hand, we have indigenous forests — where there has been no disturbance for hundreds of years. There are oaks and fir trees several centuries old. And now imagine that such a forest burns out. After all, it may never recover, or it will take 400-500 years to recover. We will lose a unique ecosystem. And what is the use of nature from such a fire? No.

— What kind of forests are being restored after fires? What trees are being planted? 

— It also depends on where the fire occurred and whether this area is subject to artificial reforestation. In Siberia, huge areas of burnt forests, as a rule, are left for restoration by nature. That is, it happens naturally there. 

But if the forest burned down near settlements, from the existing infrastructure, it is usually restored, but only with conifers — pine and spruce. Our forestry is focused on this, for it the priority is the cultivation of coniferous trees, since their wood has more valuable technological qualities. 

The fact is that when the forest burns down, in its place, small-leaved species — birch, aspen, alder. Only after a few decades, coniferous trees grow there. And since small-leaved plantations have limited economic use, they try to control the process of reforestation. It is better to grow a good pine tree than just restore the forest. But there is nothing wrong with nature.

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