Saturday, October 30, 2021

Pine Creek Loses some of its Forest

 

Malden Post Office before the fire

Attribution of a single wildfire event to global warming is confounded by lots of other factors. The Malden area and Pine Creek valley are located in a climate edge area where pine forests meet grass lands (and now dry land wheat fields) in a mosaic landscape. Pine Valley where Malden is located was already in a fire prone area. Every summer the area becomes dry enough to burn with the grasses and brush being susceptible for a longer period and the trees for a shorter period. Towards the southwest that length of time becomes longer and to the north and east the length of time is shorter. Pine Valley is in a boundary area just moist enough that tree killing fires have been infrequent enough such that the valley has significant forest stands. 

With warmer average temperatures the length of time the area is susceptible to fire is now longer. But other factors can increase fire risk - years of fire suppression and changes to land use also alter the fire risk and how a fire will behave. With lots of roads, fires in Pine Valley could be readily suppressed and put out as long as fire weather conditions were not severe. Land use changes also play a role. Over time the forested areas began to encroach into the Malden town site.

The weather event associated with this fire included very high winds associated with an Arctic cold front that surged across the area from the northeast. The high winds had followed several days of at or near record daily highs in the region. The weather set up and fire risk was predicted several days before it took place (Inland Northwest Weather.blogspot). The same weather event was also associated with a much large fire that burned over 60 miles in the Okanogan Valley as well as the very intense wildfires on the west slopes of the Oregon Cascades.   

Pre and post fire aerial images show that a fair bit of the forests that were in the Pine Creek valley burned during the fire. 

Malden 1954

Malden 2017

Malden 2021

Northeast of Malden 2017

Northeast of Malden 2021

Pine City 2017

Pine City 2021

8 comments:

Deane said...

To clarify, your photos are of before the fire and after post fire salvage logging... There's no photos of the trees after the fire / no way of knowing mortality rate of the stand. And the most unsustainable thing you can do in forestry is clear cut a partially/totally burned forest on an arid landscape because the entire process by which soil recruitment and natural regeneration of plants and trees occurs depends on dead standing and fallen trees.

Will the forest ever re-claim these locations?

Also keep in mind that these forests were just the stunted scraps on the edges of the original forest that was cleared to create the farm and ranch land along the river. This happens often in forestry. The least valuable trees for logging end up being the oldest and only significant forest habitat on the landscape, which sadly is also the part of the landscape most prone to catastrophic fire and least able to regenerate/sustain itself over time. :-(

Dan McShane said...

I did not try to quantify the tree mortality, but outside of the areas where the trees were cleared it looks to be greater than 50 percent; for example the forest not cleared directly east of pine City. It also appears that a few live trees were left within cleared areas.

I suspect the forest will come back in this area as the forested area was expanding since the 1950s (compare the 1950s aerial with the 2017) and likely even earlier. However, your point about tree removal slowing the process makes sense.

I will add that there has been substantial reforest efforts in areas of the Palouse to the south that have been pretty successful and are ongoing.

Hollis said...

Thanks for this discussion. I'm a long-time botanist, ecologist, and conservationist in WY and SD (45 years). Now I'm hearing more and more specific events, such as fire, attributed to global warming without sufficient or even any analysis of location, vegetation/habitat type, or history. It's frustrating, and I feel like my credibility is being undermined.

Deane said...
This comment has been removed by a blog administrator.
Dan McShane said...

Sorry Deane but I did not read any climate denial rhetoric in comment.

Jackson Frishman said...

Interesting. I drove through Malden shortly after the fire, and a few times since, and one of the things that keeps striking me is how much the bigger trees seemed unscathed. Houses burned to the ground and big ponderosas right beside them look fat and happy. I know anecdote is not data and maybe things look different in the woods away from the roads. But what I've seen in the area was certainly not an argument for aggressive logging on the northern Palouse.

Dan McShane said...

Thanks Jackson. I have yet to pass through Pine Creek valley since the fire, but I have seen pictures of live trees in the town, but also am aware that a fair number were killed and were cut down as they posed a hazard. I am always curious as to what burns and what doesn't. What happened in Malden as compared to other towns that wildfires burned into. The burned post office, a brick building, must have had embers that ignited the roof.

Deane said...

Yes, Jackson... Mature trees have much thicker bark and far less ladder fuels, way better equipped to survive wildfire.

However mature trees are "merchantable sawlogs" and there's very few of them remaining compared to the original landscape that was not defined by chainsaw-run tree farms managed for the next rotation of young trees, but rather managed by the main run of periodic wildfire alignment/prevailing wind patterns in fire season over the course of many, many centuries, which establishes trees that grow old surviving a dozen or more fires over the course of their lifetime.

On the bright side, on federal lands and partially on private lands there's far less funding for long term monocrop tree farming schemes of the 20th century and we're finally starting to finally look at landscape management in a different context than tree farming everything to death and that's great news for rare plants and trees that didn't have an opportunity to thrive in a monocorp landscape.

However we still have a steep hill to climb as the papers keep getting published about climate change's influence on wildfire. The LA times for example just posted this very important article today that is worthy of further discussion: https://www.latimes.com/california/story/2021-11-01/climate-change-is-now-main-driver-of-wildfire-weather