Shortly after the fire was extinguished, rare species of plants, ferns, mosses and mushrooms began to appear in the Czech Switzerland National Park. The conditions in the affected area are absolutely exceptional and therefore enable the study of a whole range of phenomena.
A team of scientists from Jan Evangelista Purkyně University in Ústí nad Labem (UJEP) will investigate them.
“It is a truly exceptional study area. I think it should be used as much as possible to investigate all possible phenomena associated with the fire area,” says geobotanist Michal Hejcman from the Faculty of Environment, UJEP.
In an interview for Seznam Zprávy, he explains what can be found out from the ashes, how they want to calculate the carbon footprint of the fire, or what could mitigate its extent.
You study the consequences of fires all over the world. Did the one in Czech Switzerland deviate in any way?
It was different mainly in terms of the area, which was huge. It is interesting that there were different types of fires as well as tree species and vegetation types. There were a lot of cultural spruces damaged by bark beetles in the decaying phase. These burn much better than broad-leaved forests, which can be seen beautifully, for example, in places where there is a beech forest – the fire often stopped at its edge. The same thing happened with the oaks – the outermost trees burned, but the fire did not reach further into the oakwood. Due to the size of the affected area, we can see the effect of the species composition of the forest on the spread of the fire.
What does species diversity affect?
If there was a natural composition of forests here, the fire will never have the area it had. But there is no point in blaming someone for making a mistake. Foresters a hundred years ago lived in completely different climatic conditions than we do. When they planted spruce stands, there were no such problems with fires, although we also have documented forest fires from this period. The climate was cooler and wetter. In addition, the forester works on a social order.
What was it like in Czech Switzerland then?
To produce quality construction wood. Spruce is good for that. Today, the purpose of the forest has changed, it is part of the national park. However, you cannot change forest management and wood composition from year to year. There wasn’t much the current park management could do about it.
After the fire, a debate broke out as to whether the park management had made a mistake somewhere. What is your opinion on this?
When you walk around the fire area, you can see that even the areas that were mined have burned. So even if the bark wood was removed, the risk of fire would not be greatly reduced. It can be reduced with a more varied species composition, but this is really a long-term issue. Park tries to get her, but it takes decades.
What is currently the most interesting thing about the incinerator from a scientific point of view?
There’s a lot of it. Plant recovery begins, one observes the species that survived the fire. They are some types of grasses, ferns, but also woody plants. They have different resistance, for example birch saplings are starting to regenerate, today we photographed beautiful oaks. Spruce regenerates the worst – affected trees usually die completely.
Rare mushrooms and mosses also appeared in the affected area. What causes their occurrence?
They are species that seek out incinerators. For example, the fire of the incinerator goes after burnt carbon. It belongs to the red list, one does not normally encounter it. Now it’s everywhere. One can see how it lives in the forest. And from this point of view, the crematorium is a very valuable study area.
You also examine the composition of the ash. What can it tell us?
Ashes will be hugely important for nutrient release and plant growth throughout the ecosystem. We are expecting a large increase in vegetation, which we will monitor. Depending on the species of wood, the ashes differ significantly in their chemical composition, so we analyze the presence of various elements in them.
Phosphorus is interesting, for example, which is normally around ten percent in the soil. Suddenly we have places where it is up to three percent. This is the limiting factor for plants. Ash is thus an important mineral fertilizer.
We then monitor risk elements that do not have a known positive role in plant growth. This is, for example, lead, which we found in large quantities in the ashes. It is not the best finding, because it is a toxic element that can cause problems for plants and animals.
What causes its increased concentration?
This is related to the use of leaded gasoline in the past. The forest has a great absorption capacity, due to the circulation of water, lead entered the ecosystem. It was bound to organic matter in the soil. If organic matter burns, it concentrates in the ashes. Normally, one kilogram of soil contains around 20 milligrams of lead, here we found samples with 200, 400 and even 900 milligrams.
How is it dangerous?
It gets further into the food chain, which can have health risks for humans. For example, for firefighters who breathed the ash that flew in the air, it can represent a certain health risk. It simply gets into the body through the respiratory tract.
Why are you interested in ashes?
Ash leaves an impact on the ecosystem that can be seen in the landscape for thousands of years. A beautiful example is that when people settled somewhere, they accumulated a huge amount of ash around them. I also work with archaeologists and see chemical signals everywhere.
To this day, we have five times more phosphorus in the places of the extinct prehistoric village compared to the surrounding area. This is due to the deposition of ashes, for example, five thousand years ago. In such places, taller and darker vegetation grows than in the surrounding area, for example, the wheat in the fields is ten centimeters taller than elsewhere.
Therefore, this fire station is a very valuable study area. We can sample different types of ash depending on the species or part of the tree that was burned. I have no information that anyone in the Czech Republic is involved in the monitoring of ashes at incinerators in such a range of analytical methods and number of samples, so these are primary data.
What exactly does research in Czech Switzerland look like?
We collect the first ashes, it is good to do it as soon as possible after the fire, because they change with time. We also have to go through the fire place because the intensity of the burning is also different and the ash is different at each temperature. And the material is sometimes burned into mineral, other times organic matter remains. In this, we can analyze, for example, polyaromatic hydrocarbons, which are toxic combustion products.
You also deal with the carbon footprint of a fire. What can it tell us?
We are able to quantify how the amount of carbon has changed in the ecosystem. We calculate how much carbon dioxide we have released, we can express it economically in the form of emission allowances. It can be compared, for example, with the production of carbon dioxide from a power plant.
How is the carbon footprint of a fire determined?
We are interested in the carbon stock in the ecosystem before and after burnout. First, we need to mark out the monitoring areas, take wood samples and calculate the carbon stock. We will then take soil samples and determine the organic carbon content of the soils and compare burned and unburned areas. It’s quite a lot of field work. We have to estimate the intensity of the fire and use the area to calculate how much carbon dioxide was released into the atmosphere.
It struck me that there are places where not much carbon has disappeared. There was a large amount of unburned wood and waste. On the southern slopes, the places are more affected, it burned down to the sand there. In such places, the carbon footprint will be larger. It is interesting to see what kind of mark the fire leaves. A forest is a system where carbon accumulates. When it burns, it is released very quickly, as well as accumulated nutrients and hazardous elements.
The forest is awaiting restoration, the likes of which the Czech landscape does not remember. How long will the research take?
The research will be long-term, we will monitor the development of vegetation and plant nutrition. We are interested in how the nutrition of plants differs on and off the burn site. But it is necessary to realize that even if there are no trees there now, it is still a forest. It has different development stages, one of them is initial. Even if the public perceives what is mature as a forest, we can still talk about the forest. Next year there will be seedlings and many trees will regenerate through cuttings. As a biologist, I have no problem perceiving the fireground as a forest.
So are fires a natural part of the forest’s life cycle?
Of course, their intensity is higher because of humans, quite often people also initiate them. But in sandstone areas with pines, fires occurred over a long period of time. Fire belongs to the ecosystem and to some extent it is a natural matter.
We know this because burned trees produce carbon that stays in the soil. It is then possible to separate them and date them. And we have carbon from the entire Holocene, i.e. the last ten thousand years. Although fire arouses very negative emotions in the public – and it is not surprising if it threatens people’s health and property – it is often beneficial for nature.
Burning will make it possible to more quickly transform the existing inappropriate composition of forests into forests close to nature. Furthermore, I don’t think the fire will have a negative effect on tourism once the park is fully open to the public. Seeing the fire scene and the restoration of nature with your own eyes will attract a large number of curious tourists.