why we can’t ‘just’ split big forests into multiple blocks so when a block burns it doesn’t spread through the whole forest.


Well the title is the question.
With ‘split’ I mean create some space between blocks where fire has nothing to travel to the next block to spread.

I imagine that actions like dropping water with helicopters would also be unnecessary since we could ‘give up’ a burning block and then the fire would be over.

Or am I too naive about it?

In: Earth Science

We do this in forestry blocks in Australia. They are called “fire breaks”. If you lease the land, you must keep the fire breaks free from debris & keep the grass slashed or you can be fined.

These splits are called “Fire Breaks”, and that’s one of the main things which forest fire fighting crews do. Building them, and maintaining them, is too expensive to do all the time. They also have to be quite large to protect against spread of large fires, which makes them unattractive. They can also lead to erosion and other environmental damage.

A far better strategy is more frequent, smaller, fires as nature intended. This could lead to burning down more homes, but perhaps that would send the message “Don’t build if a forest that burns regularly or your house will get burned down regularly.” More people need to get that message.

For one, money. That would be extremely expensive to do it over a big enough area. Extremely resource intensive also, to keep a 200 yard stretch of forest Mike’s long clearcut down to the dirt.

Then that would also create environmental issues and cause problems for animals, I think they have figured out that leaving islands of trees behind after clear-cutting areas is still bad for local populations of animals. Plus more erosion, etc.

Also, fire is good for a lot of species, at least small regular fires. The problem is we have been stopping all fires for the past several decades, which leaves us with a giant pile up of fuel on the forest floor that creates giant raging fires that kill everything, as opposed to small brush fires which clear out undergrowth and clutter.

This is vaguely what proper forest management is supposed to do. One factor on why forest fires can get so big and spread so fast is when there is too much “junk” on the forest floor. Stuff like little sapling trees, dead trees that have fallen, years and years worth of leaves. It’s often that sort of thing that catches fire first. Big, mature trees can often withstand a relatively fast fire around their trunks, but if there’s too much litter, the fire burns too long and can reach up into the tops of the big trees, leading to the infernos we see. So one strategy that has been deployed to fight this is “controlled burns” where firefighters and forestry people will pick a section of woods, and go in and slowly and methodically burn off the excess junk. Then the next time a wildfire starts, it has way less fuel in a given area to burn.

One of the lessons learned from the Yellowstone NP fire back in the late 80’s was it’s better in the long run to sometimes let smaller fires burn more often, because then they don’t become massive. They had been suppressing any and all fires in Yellowstone for years, and when something finally caught and they couldn’t get it under control, so it burned most the park to a crisp. So now, they take a slightly more “hands off” approach, in that if a fire starts, they keep an eye on it and let it burn at least for a while

You’re describing [firebreaks](https://en.m.wikipedia.org/wiki/Firebreak). The issues as I understand them are:

With wind fires can jump the gap or burning embers from one side can blow across. Embers can jump firebreaks of 600-800 feet on occasion.

They are not always practical to create given the shape of the land – hills, mountains etc

They are hard to maintain given you need to keep them free of most vegetation across a large area.

People own land and so you can’t just cut firebreaks on a perfect grid across the countryside.

Edit: Because a lot of people are commenting on the numbers I gave for 6-800 feet. I’m referencing one of the numbers given in Wikipedia of a 600 feet wide firebreak which was actually jumped. But it also mentions that embers can fly further and start fires further afield.

Because that is an IMMENSE amount of work. Ever cleared dense trees? It’s very difficult and expensive work. You don’t do it unless you need to. In tall, established forests an effective fire break has to be quite wide, 30 ft or more. Cutting a single miles long 30 ft wide swath through a forest would be the work of years, and it might not even be effective if the wind is wrong when the fire happens. It’s just not economically feasible.

My brother was a “hotshot” who fought forest fires. I asked him how is it that green trees burn so easily? He said the heat from a forest fire is so intense, it dries out the everything as it approaches. He said the fire super-heats the sap inside the trees and the trees just explode all around you. He also said the noise from a fire is so loud that it’s like standing next to an old train tracks when a noisy train passes.

His unit was ‘burned over’ twice. They had to quickly dig holes and place a kind of tin foil over themselves and let the fire pass over them. He ended up hurting his back in a helicopter accident and has had 12 surgeries (he now has full use of his limbs).

Every small patch you make from a large patch of forest creates more edges. Edges of vegetation patches tend to have more light, weeds and invasive species, which can compete with local native plants and animals (research “edge effects” and “habitat fragmentation”). However, you can have a large patch of forest that is periodically burned in small patches (mosaic burning) over time to reduce fuel loads and allow access to intact forest adjacent for movement of animals.

It’s also worth mentioning that, especially in pine forests, fire is part of the natural cycle. Many pine species’ pine cones won’t open and seed until there is a fire, helping ensure that the new growth won’t have a bunch of trees blocking the sun. If I remember correctly, part of the reason the 1988 Yellowstone fire was so bad (in addition to the drought that year) was because we had been too effective in putting out fires, meaning there was a lot of unmanaged undergrowth and dead tress, and not a lot of younger, healthier trees. once a fire got going, it took off. To this day, Montana and Wyoming forest service follow strict guidelines about which fires to fight and which to let burn.

Here in Colorado the answer is $$$. Not profitable to send people out to do the work and timber has no value

If you walk through a forest for an hour and realize that you’ve seen a few acres out of 100’s of millions, you’ll begin to see how impossible it would be to even manage a single National Forest much less a state like California or Idaho. Besides, burn is necessary for forests. We just happen to place ourselves in danger.

Others have made good points that maintaining such a network of fire breaks would be expensive and resource-intensive.

Dividing forest habitat like this also creates what are known as *edge effects*, which can be ecologically devastating for some species. Many large animal and tree species require large tracts of dense forest to thrive. These forest edges create small, but potentially critical differences in climate and environment that can be detrimental to those “deep forest” species: for example, light, wind, and temperature can enter the forest horizontally, new species can establish themselves along the new edges and start to encroach into the forest and outcompete established species, and the breaks can hinder migration throughout the forest.

Lastly, fire is quite a beneficial process in many of Earth’s ecosystems. Humans have managed landscapes in a healthy way via fire for millennia. Over the last couple centuries, imported colonial forest management theories have called for an unhealthy level of fire suppression. As a result, fires in recent decades have been far more intense than they have been historically. Additionally, drought events are occurring with greater frequency, causing more frequent and intense fires than probably occurred historically, at least in North America.

Everyone has already mentioned fire breaks, but there is a little bit more too it. Even something as seemingly simple as a small gap in the forest often needs to be heavily assessed to ensure it isn’t damaging to protected species. Habitat fragmentation can cause a lot of issues, especially for large predators, and chopping up a forest could potentially do a lot more harm for what lives there than we expect.

Fires spread across firebreaks due to wind. Plus, if you’re in the hills, when it rains, bare ground contributes to mudslides because the soil collapses since there is no vegetation holding it in place. The mudslides will take out huge numbers of trees.

We already do this, and is very useful, but it sometimes is not enough. Maybe is enough distance for the wind to not be able to extend the flames themselves, but spare and small burning material can spread.


So you want to help stop the destruction of forests by destroying sections of forest to create space between them ?

Other comments are covering how fire spreads, so I’ll add this.

Forests have specific and nuanced wildlife ecosystems. The species that thrive in a forest, need the forest to exist as it has.

For example, you may remember one of the first and most important legal challenges against logging of old-growth forests: *Northern Spotted Owl v. Hoden* (later *Northern Spotted Owl v. Lujan*).

Not to get into all of it, but, one thing that came about. Lumber argued that to protect the owl, they would only ‘clear-cut’ specific squares and as such the forest would look like a checkerboard. Wide swaths of empty nothing next to wide swaths of forests. But that didn’t work. The owls and other birds of prey need cover. They can’t hunt in open fields. Meanwhile the animals (who are prey) that live in cover are exposed in open fields. There are few species that live in old growth forests that can exist in a checkerboard of open fields. That’s just not how it works.

Point being, there are many factors at work here that have an influence on forest management. It’s not just preventing forest fires – which, I’ll add, is a natural part of forest health – but of course NOT fires due to habitat loss/climate change/assholes burning forests because they launched fireworks during a ‘gender-reveal’ party.

We do it sometimes, but it’s more expensive than you would expect and it doesn’t always work.