Hacker News Reader

Comment by efa | Hacker News Reader

>Prescribed burns are generally focused mainly on acreage and reducing the amount of fuel available for wildfires; cultural burns are focused on what needs burned to revitalize woodlands and promote biodiversity.

I wish they'd elaborate on how this is done. Focuses on what needs to be burned? Meaning a type of tree? Just the undergrowth? Curious how fire can be controlled to just specific elements in the landscape.

View on HN

From my layman understanding: usually it's just dry undergrowth and dead stuff that burns. Getting a healthy tree to burn needs a lot of heat or time, so if you burn frequently enough the undergrowth burns away long before the trees have a chance to catch fire. If too much flammable material has built up, remove undergrowth from around the tree trunks (or inversely, stack dead branches under trees you want to burn, though not sure if anyone does that).

I think it's really hard to burn a healthy tree. Water is good at controlling temperature. Even you use a blowtorch on a healthy tree. You will just make a black taint on it. And a big healthy have tons of water in it. Make it even more durable to fire.

To make a healthy tree burnable. You first need tons of heat source to prepare the wood itself so it is dry enough that actually burnable. But a healthy forest shouldn't have that level of heat source to make it doable (otherwise it will burn itself away someday, just like current situation of CA)

Prescribed burn here exists to remove the fuel, so it never pile up to the level that "Once it ignited, everything burns regardless of it is a healthy tree or what. And it burns forever because everything is burnable at this level of temperature".

Reply on news.ycombinator.com