I was talking about fires in typical "marten bush"-type boreal mixed forests (this is what we call "taiga" here), which are similar across the globe and are made up of mixture of several conifer species, such as spruce, fir, five- and two-needle pines, tamarack, and deciduous trees such as aspen and birch, with the bottom layer composed of several species of feather and string moss and dwarf shrubs (mostly of the heaths family). Such forests gradually accumulate a thick layer of slowly decomposing organic matter, up to a few feet deep, which contains most of the trees' root systems, so a fire will kill most trees if the litter is completely dry. Fires in such forests are high-impact and it takes up to 250 years for the climax community to reestablish. The limiting factor has always been the nature of these fires - since they usually occur in the end of a dry spell, when enough humidity accumulates in the air, the dry thunderstorms that spark them usually turn into good rains within a week or two, so only a limited patch burns out. Our taiga is a patchwork of such burnt areas of different age.
It IS different in some types of boreal forests.
The Scots pine (a two-needle pine), which is one of the key tree species of the boreal zone of the Northern Hemisphere, and the #1 source of construction lumber, has a root system and bark adapted to low-intensity fires. It prefers poor, well-drained sandy soils where many other trees fail to establish, but eventually appear as undergrowth, and regular fires kill off all deciduous undergrowth as well as other conifers, including five-needle pines which have flat, superficial root systems. The Scots Pine benefits from such fires because they create well-spaced, "park-type" mature forests with just a thin layer of lichens or moss over the mineral layer, and kill off deciduous trees and spruce that create shade, which in turns raises the humidity of the soil and the number of pathogenic fungi dangerous to pines, such as Heterobasidion rot. Most importantly, fires mineralize all organic matter in pine forests, allowing all excessive nitrogen to wash out and limiting the competition from nitrogen-loving plants that need organics. Being much drier, such forests burn more often and benefit from fires every few decades. There is actually a big controlled fire program in Sweden, aimed at reestablishing such forests where there are now mixed forests. But even with all the efforts, such stable fire-resistant forests are declining. Here is an example of what a really good fire-resistant pine forest looks like, just a couple of years after a fire.
Low-intensity fires are also relatively easy to stop in these good pine forests. Oftentimes a furrow made by a tractor or manually is enough. Spray packs work well, too.
With good mature taiga forests, only rain helps. In my experience, there is very little use in the work of firefighting teams when it comes to taiga fires far away from the road network, and Be-200 flying boats are mostly used to protect critical infrastructure locally (when they are available, and they're usually elsewhere, protecting certain people's villas in the Mediterranean). This is us watching our second camp burn down, after several days of trying to stop the fire. We spent another week sitting in the middle of a mire, waiting for the helicopter to pick us up
However, here, even Scots pine forests have been suffering lately from overly frequent fires, both natural and caused by humans, combined with irrational logging regulations. For instance, a few years ago you could buy a hectare of freshly burnt pine forest (and probably still can, I haven't checked), with plenty of trees that would eventually recover, for the price of an ice cream, something like $1, so naturally, no one would let such forests recover naturally, leading to catastrophic losses of old-stand pine forests all over Siberia. Ironically, most of it was exported to China and probably ended up in the U.S., because you guys are key importers of processed lumber from China. Because of this, in some areas, especially adjacent to China (Irkutsk region, Buryatia etc.) arson is common. There may be a lot of money in the whole firefighting thing, but there is WAY more money in logging, especially now that our country, which is a key exporter of timber, has been trying to limit exports of unprocessed timber. So those with a fondness for conspiracy theories might want to look into how the timber market has been changing in the past few years.
Larch/tamarack forests are also quite fire-resistant but excessive burns kill them off, too, and larch takes much longer to regenerate, so these forests are even more vulnerable to the erosion issue that I mentioned. Nevertheless, freshly burnt (up to 15 years) larch forest in Eastern Siberia is prime sable habitat.
We also have fire-resistant birch forests here in Southern Siberia, with peculiar herbaceous communities, but they are more of a curiosity.