Trapper Creek fire

[kepPNW]

The fire boundary has expanded a bit down from Howe Ridge and it appears that most of the Sunshine Trail and Rim Trail and Shortcut Trail may be in the burn. But I don't really understand how the fire could burn even part way down into the Trapper Creek Canyon but spare Observation Peak and Sister Rocks, which is what the maps show.

Yeah, Sunshine looks toasted.

Observation Peak was definitely lighting up the IR the other night, too. That boundary they've been drawing can't be taken all too seriously, as they've had almost no visibility to go by. (As they even said.) NASA provides another view, through the smoke, though...

So far, no indication Sister Rocks got fried!

[retired jerry]

I saw this from odf

In recent years, there's been a small increase in acres burned per year, but paled compared to those years in 1930s that include the Tillamook burn

But, this year, 1 million acres have burned, more than three times as much as any of those 1930s years

Hopefully this is not a trend

[drm]

Jerry - It's important to note the difference between eastern and western fires. Even without suppression, fires in the wet west were quite rare - rare enough that modern fire suppression has been going on far less than one typical fire cycle. The typical major fire frequency in the west can be up to a thousand years, compared to a couple decades on the east side. Western temperate rainforests just don't dry out enough in a typical summer to burn - for centuries on end typically, and even when they do tstorms are extremely rare. So when conditions do set up for a west side fire, the fuels are just overwhelming, so they can then be huge.

[kepPNW]

The typical major fire frequency in the west can be up to a thousand years,

First I've heard that, Dean. Where might one read more? Makes some intuitive sense, but I do wonder how such a thing might be known.

[bobcat]

Here's a short and quick outline of fire cycles in Oregon from the Oregon Forest Resources Institute. They do note that when fires did occur in western Oregon, they were more massive and intense than fires in other parts of the state. These days, of course, we have the added frequency of human-caused fires to add to the natural events.

[Peabody]

If ya ever want to go down the "Rabbit hole" search for "Bull Run old growth" on Google scholar.


Forest Fire Regime of the Bull Run Watershed, Oregon


Windthrow Disturbance, Forest Composition, and Structure in the Bull Run Basin, Oregon


Spatial and temporal patterns of windthrow in the Bull Run Watershed, Oregon

[drm]

The typical major fire frequency in the west can be up to a thousand years,

First I've heard that, Dean. Where might one read more? Makes some intuitive sense, but I do wonder how such a thing might be known.

After the Eagle Creek fire, I went to a number of presentations in the local area given by scientists, and that's where I picked that info up from, so I don't have a link for it. As to how it would be known, I imagine growth rings and sediment layers can be used to date major fires, but that's just a guess.

[retired jerry]

https://en.wikipedia.org/wiki/Yacolt_Burn

"The Yacolt Burn (also known as the Yacolt Fire, the Yacolt Blaze, the Yacolt-Cispus Burn, or the Columbia Fire of 1902) was the result of many weather factors as well as careless humans. The summer of 1902 had been drier than normal and early September winds blowing from west to east. A build-up of slash from loggers had not been burned off properly in the preceding two summers.[4] On September 8 a fire was started by boys trying to burn a nest of hornets near Eagle Creek, Oregon. Other large fires there occurred independently or combined with other fires started soon thereafter, including one started by a locomotive in Dodson, Oregon.[5] Other accounts cite lightning as the genesis of the fire as well as careless campers and berry pickers, hunters, and loggers cutting slash.[3][4] The fire spread rapidly, extending from Bridal Veil, Oregon to Cascade Locks, Oregon before burning debris carried across the Columbia River to Washington. It traveled 30 miles (48 km) in 36 hours and destroyed 238,920 acres (967 km²) of timber, about 12 billion board feet (28,000,000 m³), in Clark, Cowlitz and Skamania counties."

Fires have long been caused by humans

Yacolt Burn was more similar to the Eagle Creek fire of a few years ago

Yacolt Burn had west to east winds in September. The fires we're seeing now had a east to west wind which is worse, because they blow off the cascades, lose elevation and warm up, very low humidity.

[kepPNW]

The typical major fire frequency in the west can be up to a thousand years,

First I've heard that, Dean. Where might one read more? Makes some intuitive sense, but I do wonder how such a thing might be known.

After the Eagle Creek fire, I went to a number of presentations in the local area given by scientists, and that's where I picked that info up from, so I don't have a link for it. As to how it would be known, I imagine growth rings and sediment layers can be used to date major fires, but that's just a guess.

To establish a pattern of 1000-year cycles would seem to require data predating the Missoula floods. Far too long for tree ring records, but the sediment layers sound like a good thought. Intriguing!

(I'd actually have expected cycles closer to those mentioned in bobcat's cite, in the 100-400yr range.)

[drm]

To be more specific, they said that western cycles ranged from 200 to 1000 years.

I just did a search on "western oregon fire cycles scholarly articles" and came up with Fire and Vegetation History from the Coastal Rain Forest of the Western Oregon Coast Range. The abstract says that charcoal and pollen analyses were used to determine fire frequency at a specific location in western Oregon.

High-resolution charcoal and pollen analyses were used to reconstruct a 4600-yr-long history of fire and vegetation near Taylor Lake in the wettest forests of coastal Oregon. Today, fires in these forests are rare because the season of ignition does not coincide with months of dry fuels. From ca. 4600 to 2700 cal yr B.P. fire episodes occurred at intervals of 140±30 yr while forest vegetation was dominated by disturbance-adapted taxa such as Alnus rubra. From ca. 2700 cal yr B.P. to the present, fire episodes have become less common, occurring at intervals of 240±30 yr, and fire-sensitive forest taxa, such as Tsuga heterophylla and Picea sitchensis, have become more prominent. Fire occurrence during the mid-Holocene was similar to that of the more xeric forests in the eastern Coast Range and suggests that summer drought was widespread. After ca. 2700 cal yr B.P., a decrease in fire episode frequency suggests that cooler conditions and possibly increased summer fog allowed the establishment of present-day Picea sitchensis forests within the watershed. These results provide evidence that fire has been an important disturbance agent in the Coast Range of Oregon, and variations in fire frequency and climate have led to the establishment of present-day forests.