# How can massive forest burning be an entirely terrible thing?

I'm writing a story about a fantasy medieval world where flightless dragons roam vast tropical rainforests (like Vietnam or Borneo) and preys on animals and people alike. These dragons are so powerful yet elusive that the only reliable way to hunt them is by burning a big chunk of the forest to drive them out of hiding, forcing people who live in that forest to move away and lose their homes. The main conflict in the story is that a dragon is terrorizing a village, but the villagers don't want their village and the surrounding forest to be burned down, so they try to hunt this dragon before the authorities deem it necessary to set fire to the forest.

At least, that's how I envisioned it at first. But then I remember that controlled burning is a thing, and is sometimes used to clear land for agriculture anyway, so it's not like this massive forest burning is entirely terrible. I know that forests play a bigger role in pre-industrial societies, but I don't know if they're important enough to the extent that losing an entire forest renders the land uninhabitable. But I already wrote the forest burning as a bad thing and should be avoided, so how can I justify that?

• burned forest is only productive for a few years before it becomes basically wasteland.
– John
Dec 20 '20 at 16:00
• @John no, i would say the opposite Dec 20 '20 at 21:12
• @Topcode those are fire forests where fire is common and the plants have evolved for it. jungle is a VERY different thing. en.wikipedia.org/wiki/Slash-and-burn
– John
Dec 20 '20 at 23:02
• “Controlled” burns are not something that medieval villagers are known to be proficient at... Dec 21 '20 at 7:33
• It's pretty plausible that the locals just really wouldn't want their forest burned. How would you feel about someone burning down your house and saying "you can just build a new one in a few years"? Now, instead of a house, it's a small village that your family has lived in for generations. Does this really need explanation? Edit: I should note that I am aware that you are not talking about a village here and that it just seems like a reasonably analogous case. A forest may well feel like as personal as a village to a forest dweller. Dec 22 '20 at 0:17

### The 445 Australians who died of smoke inhalation from the 2019/2020 bushfire season couldn't be contacted for comment.

Big forest burning is a terrible thing: My state (South Australia) had a higher death toll from bushfires this year than we did from COVID-19.

(Let that sink in: WORSE THAN COVID19!)

I'll direct you to the Australian Institute of Health and Welfares report on these fires.

Personally I had my first Asthma attack since childhood, my partner's mother had the fire front up to her backdoor (the online maps showed it overran her house, and we lost contact with her for 48 hours), and the bulk of my social circle switched from a "She'll be all right mate" attitude to a borderline doomsday prepper.

The mental health impacts of this will never be truly known, as we went straight from fires to floods to COVID-19 so this is hard to isolate, but it burnt 12 million hectares, 40% were worried about someone's safety, 45% were affected by smoke, it killed a billion animals (the koala is predicted to go extinct in some states), 2 major cities (pop > 1 million) were cut off for weeks from all their supply routes, and it emitted nearly a year of our CO2 budget.

And that was only 1.8% of our land area. If your people go round burning their entire forest down systematically looking for this dragon the consequences are going to be far worse.

Controlled burns are manageable and humans can get close to them, a traditional Australian Aboriginal burn only burnt tall grass and undergrowth, it didn't burn the trees at all, and you could walk right up it - your dragon could probably mosey around the fire front and otherwise ignore it. A fire needed to flush out such a dragon would need to be a destructive wildfire similar to the level which devastated Australia earlier this year.

• I can't diminish the pain or loss, but this instance is not a reason to never have forest fires. Ecosystems and various plants have grown with a fire once in a while in mind. So it doesn't answer the question why a (controlled) fire would be a bad thing for the OP's setting. Dec 20 '20 at 12:24
• @Trioxidane Unless your dragon has a fear of fire or something; A controlled burn will not flush out a massive dragon - in a controlled burn you don't burn the tall trees, you burn the undergrowth, small trees, and grass, and it's so cool you can walk calmly within 50cm of the flames (you need to to keep it under control), and a dragon will just meander around the fire front and stay hidden. If you want to flush a dragon out with fire, you'll need a massive wildfire that burns large animals to a crisp if they don't flee immediately. That is a totally different thing to a controlled burn.
– Ash
Dec 20 '20 at 13:53
• @Trioxidane why waffle on about controlled fires, when the OP asks about "massive forest burning"? Note massive. As in enough fire to burn out a Dragon! Dec 20 '20 at 14:24
• +1 for the following statement: Big forest burning is a terrible thing. Controlled burns are intentionally used in small areas for specific purposes because all it takes to loose control is wind. While it is true that Mother Nature uses fire to advance nature (indeed, some pine cones won't drop seeds unless a specific high temperature is met), that's not common. No one in their right mind would try to burn a large section of forest - and it takes decades (if not centuries) to fully recover from the burn. There are huge swaths of the 1988 Yellowstone Park fire that still haven't recovered. Dec 20 '20 at 18:21
• "WORSE THAN COVID19" Please note that this is dangerous misinformation for two reasons: 1) Australia has had an incredibly low death rate, given the world average death rate Australia would have 5430 deaths and 2) Wildfires aren't viral, so they can't suddenly explode all over the world and don't have the potential to kill between 1 to 5% of the population if not regulated. I am not saying this to diminish the horribleness of wildfires and the risks from climate change might be even bigger than COVID-19, but we shouldn't compare cherry picked death rates like that to make statements like that. Dec 21 '20 at 7:29

The forest is not random wildness. The people who live there have made the forest what it is.

Amazon forest 'shaped by pre-Columbian indigenous peoples'

Your forest dwellers do not cut trees and plant corn where trees used to be. They live in the forest. The forest provides what they need. This is not by accident. The forest is not a random wild growth. These people have managed the forest for thousands of years, cutting back undesired growth and encouraging trees and plants that provide medicine, building materials and food for themselves and for animals. Your people know when and where to go in the forest to get what they need to live. They are keepers of the forest.

This forest does not burn. There are trees that are thousands of years old and some of these trees are rightly revered as powerful entities.

If the forest is destroyed (and burning will destroy it), it upends what this culture has built over the millenia. It destroys the culture itself. The people will be scattered, reduced to working for a wage on the farms of other peoples.

Now the trick as a writer: take the ethos of this people and move it to dragon hunting. The outsiders are threatened by a dragon: kill it. The outsiders are threatened by a forest: burn it. Your people are not like the outsiders, but how are they different? How can your people address the problem - not just the problem of the dragon, but really the problem of the powerful outsiders who can burn the forest. Hint: how was this dragon living before it started eating people?

• I think you're on the right track -- the forest is a source of many things -- wood, food (plants, animals), possibly medicine (herbs, tree bark, etc.). Grasslands can't support the same density of people as forests, and even grasslands are going to take some time to grow back in, so it makes the villages uninhabitable for many years unless you have some sort of agriculture, food stores for the year, and alternate fuel sources come winter.
– Joe
Dec 21 '20 at 17:35
• Also, "forest" can include many improvements. For an example, look up "living root bridges" Dec 22 '20 at 5:07

Metal poisoning

Today I happened on an article about metal smelting in trees: https://www.nytimes.com/2020/02/26/science/metal-plants-farm.html

This seems incredibly cool to me and might assist your answer. The ground might be easily polluted by nickel in that area. Much of the trees and vegetation remove it from the soil, storing it in themselves. The vegetation likely stores it in itself as protection against parasites, like woodworm or caterpillars. To have good farmland, the trees must be removed root and stem in a careful way, so the nickel doesn't return to the soil and poison the plants. However, burning the forest will possibly increase metal in the air and water, polluting both enough for serious health effects and destroying farmland. The people don't even need to know what causes it, they just need to have it culturally ingrained by generations of living there. Burning trees with green sap is dangerous. For me it would be doubly interesting, as it seems so outlandish but turns out true.

## Conditions and technology don't allow for controlled burning.

As noted in Ash's answer, controlled burns (aka "hazard reduction") are low-intensity operations that may not be enough to flush out a dragon. But also, even with 21st-century technology and fire science, controlled burns often aren't an option.

Contra some of the post-mortem discussion about the 2019-20 Australian fires, the main limit on controlled burning is not political opposition but the narrowness of the window in which conditions are right for it.You can't do them during a wet winter, because a low-intensity fire will just fizzle. You can't do them during hot/dry/windy weather because of the risk that the fire will get out of control - and weather forecasting is important in planning this.

Even when the weather is right, care has to be taken to avoid causing erosion - burning slopes or riverbanks makes it easy for the topsoil to be washed away, which is very bad for people depending on that ecosystem.

For more detail on some of the considerations involved, here are the New South Wales Rural Fire Service standards for low-intensity hazard reduction burning.

In a low-tech setting without radios, vehicles, or weather satellites... it probably isn't any easier. Unless your dragon is courteous enough to show up at just the right time of year, your villagers have no reason to believe that the fire will be controllable.

By burning the forest, you not only decrease oxygen production, but you kill many animals, if it gets out of control (which still happens today) whole forests would burn down, and if this was in a medieval society, there were no such things as controlled fires.

Edit: Also, a rainforest burning is so hard to put out because the thickness, as shown by the Amazon Fire, and the variety of elements/compunds found there which make chemical fires which are much harder to put out, especially if they have high combustive chemical concentrations, etc. even if rare, also, the height of the trees, in a rainforest, the trees are so tall they could pass over many borderlines

• Why can't they have controlled fires? Although the clearing or keeping wet of an area of a few meters wide all along the border you want to burn can be a huge chore with non modern means, but while work intensive it certainly isn't rocket science. Japanese in ancient culture even used already burned wood as fire retardant among other things, as because it already oxidised it was difficult to burn again. Dec 20 '20 at 12:00
• well, they didn't, as controlled fires had to be very little, and reachability of the fire, in a forest, you need to put out entire trees, or have something stopping the fire from continuing, which is very unrelliable, and accidents with this last one still happen, and the japanesse did, but most other cultures did not know about this, also, if any bit of flame made it out of the marked area, they couldn't react fast enough, if it burned high enough, and it would burn even more forest, a worse version of the australian bushfires or amazon fire, as they did not have water spouts, etc. Dec 20 '20 at 12:26
• also, unrelated, but oxidised materials can be re-burnt by chlorine trifluoride, but that question and reasoning is great, keep questioning all, like that, and you'll get far in life, also your answer might also help me with something unrelated Dec 20 '20 at 12:32
• Can you clarify why high potassium concentrations would impede firefighting? Elemental potassium is hard to extinguish, sure, but you're never going to find it in nature, precisely because it's so reactive. Dec 21 '20 at 21:14
• to you i say bannana, also, it was an example, there are chemicals that make fires harder to put out, but i didn't mean potassium as such, and only that, i will correct it edit:now i have corrected it Dec 22 '20 at 15:11

## Controlled burns are not massive fires.

Several commenters have already mentioned this, but I thought it was worth fleshing out in an answer.

Controlled burns typically cover a few hectars to a couple thousand hectares. A thousand hectares is about 10 sq km (4 sq miles). A dragon's territory is likely to be 40-1000 sq km. The minimum size would overlap with the largest of controlled burns, but the maximum size would be 100 times larger.

Assuming the controlled burn covers the dragon's whole territory, controlled burns are designed to clear underbrush, and do not greatly impact local fauna, other than to change the available food sources. For predators, the controlled burn may even increase their available food sources long term:

Prescribed fire has an indirect, positive effect on large carnivore populations due to the high quality ungulate habitat it creates. (Source: Effects of Prescribed Fire on Wildlife and Wildlife Habitat in Selected Ecosystems of North America)

Even uncontrolled wildfires have limited immediate population effects,

Despite the perception by the general public that wildland fire is devastating to animals, fires generally kill and injure a relatively small proportion of animal populations. ... Animals with limited mobility livingabove ground appear to be most vulnerable to fire-caused injury and mortality, but occasionally even large mammals are killed by fire. The large fires of 1988 in the Greater Yellowstone Area killed about 1 percent of the area’s elk population (Singer andSchullery 1989)

(Source: Wildland Fire in Ecosystems)

After the controlled burn, much of the tree cover will still be intact, so finding the dragon will still present a challenge. I couldn't find a picture immediately after a controlled burn, but in the following image, you can see the large trees are still present.

## So what would work? Defoliation

Burning a big chunk of forest to drive the dragon out of hiding sounds more like a "salt the earth" defoliation strategy, similar to using Agent Orange during the Vietnam War to "was to defoliate rural/forested land, depriving guerrillas of food and concealment and clearing sensitive areas such as around base perimeters" (Wikipedia).

These strategies were disastrous for locals. The military explicitly aimed to "destroy the ability of peasants to support themselves in the countryside" in the short term, and the herbicides had long-term health effects for as many as 3 million Vietnamese and 40,000 US Veterans (Wikipedia). For your fire-based defoliation, health effects could easily result from smoke inhalation instead of chemical exposure.

Large fires such as those that occurred in Australia and the Pacific Northwest this year are more similar to these military strategies than they are to controlled burns, in both scale (3,100,000 hectares sprayed with defoliants vs 400,000 hectares burned in Oregon - 18,000,000 million burned in Australia), and in ecological impact (covered extensively in @Ash's answer).

The military does not typically have the ecological health of an area in mind, and the local community is likely right to worry about the impact of military intervention.

• if in a birch forest for example, the trees would very easily catch fire Dec 29 '20 at 15:01
• @dexyan, this is a misconception. Birch trees are recommended for planting to slow wildfire spread. Leafy trees like birch burn more slowly than needle trees. It’s only after birch wood has been dried that it makes good firewood. Live birch is too wet. Dec 30 '20 at 16:53

Burning an entire section of forest might not be terrible in the long-term, but for the people living there in the short-term, it would be a nightmare.

If they gather food in the woods, or hunt there, then burning everything down takes away at least part of their food supply. If they use wood as a building material, burning all of the wood in a several-mile-wide radius will make construction and repairs significantly harder for a while. And if the village burns, either intentionally or unintentionally (the wind can turn a controlled fire into an uncontrollable one quickly), well. I think the problems there are self-evident. It's even worse if the village relies on agriculture and their crops burn before the harvest. Homelessness and starvation are not fun.

And of course, you can always fall back on spiritual/religious/cultural reasons for why burning the forest would be a bad thing. Maybe the villagers believe that burning healthy plants is a terrible waste of Mother Nature's gifts. Maybe there's a sacred tree out there that wouldn't survive a blaze. Whatever the case, they just can't in good conscience sit back and watch as the forest they've been in for generations is reduced to ash.

# Two words: nuclear autumn

A 2019 study[1] examined the effects of a limited nuclear conflict on world climate with updated modeling, and concluded that a relatively modest nuclear exchange would yield enough aerosols to cause a decrease in global temperatures for years afterward. That in turn would lead to decreased agricultural output, and consequently increased starvation and death, even in areas very distant from where the conflict took place.

The important part here, though, is that any process that puts sufficient material into the upper atmosphere could cause this effect, massive fires included. And we have evidence that massive fires do create high-altitude particles (see another study from 2019[2]). So, burning a large forest to drive out a dragon would likely decrease food production in the local village, as well as possibly cause significant impacts on contemporary civilizations around the world.

Water Cycle

Forest are an important piece in the water lifecycle, as their ground absorbs water and their trees produce water also. Removing an massive forest could lead to unstable climate, inducing dries and floods all over the world.

The fire, being draconic, is far hotter than your usual controlled burn, or even ordinary forest fires. It burns up all the organic material. There is little ash left and basically you have scorched rock.

It is not only a disaster when it happens but leaves the land ruined for generations.

In places where controlled burns are a regular occurrence, this encourages the growth of fire-tolerant plants. Indeed, some species become fire-dependant, and cannot reproduce without fire.

In such a place, a massive burn to flush out or kill a dragon would still be a disaster to the people living there, as it would also kill people and destroy crops and homes, but such a forest's plants and animals would recover and return in less than a human generation.

However, not all forests are populated with species of plants that are fire-tolerant or fire-dependant. In such an environment where fire is unusual and limited in scope, a massive fire would devastate the area to the point where it might take a century or more to recover fully, and where displaced people are looking for a place to live, it may never recover, as people turn the land from forest to farmland... which is likely to become nutrient-deprived and poorly productive within a few years.

Such a massive fire in a non-fire-adapted forest would be not only an immediate human disaster as well as a disaster to the flora and fauna, but a massive and potentially unrecoverable loss of primary production for the foreseeable future.