Fire and Fuels

This piece in The Economist talks about wildland fire and firefighting in Alaska, a topic of interest to us. It appears, though, that pieces of information have been collected in order to generalize to the below conclusions.

More heat than light
There are two big cautionary lessons here. One is that, beyond the dysfunction in Washington, the excellence of America’s institutions is creating a false sense of security about the long-term threats its politicians are neglecting. That is starkly true of America’s early efforts to adapt to global warming. But much the same could be said for its armed forces, diplomatic service, judiciary and other institutional crutches against manifold threats. This is not sustainable. Without better leadership, there will be a reckoning.

The second lesson, given how little public attention has been paid to the wildfires, is that there is little reason to think increased natural disasters alone will produce the necessary leadership. Many Americans, and by extension their politicians, are already becoming inured to global warming’s devastating effects.

(my italics, “little attention”, where? Not in government nor in the press…)

What was most interesting to me was that Roger Pielke, Jr. decided to look up trends (on the Alaska State Government wildfire database here)

There’s an interesting discussion on Roger Pielke (Jr.)’s Twitter feed here. He found the statistics and posted them (see figure above). David Greene tweeted a correction, so it looks like someone checked on Roger’s figure. Meanwhile I took a look at 2009 to check David’s checking and found that 1.35 M acres were WFU, but I couldn’t find any WFU in the years before or after. Maybe someone knows more about this…

But back to the Economist story.

“A few thousand wildfire fighters stand between America and a terrible reckoning” That seems a bit of a low estimate, based on other figures.

“Wildfire fighters are racking up twice as much overtime as they were a few years ago, in part because there are fewer of them. The number of federal firefighters has fallen by over 2,000. That is a result of cost-cutting and also increased competition for free spirits from fracking and other extractive industries in the western states. More hazardous infernos are another disincentive. Almost 200 wildlife firefighters have perished in the past decade. America is therefore starting to run short of some of its most heroic public servants even as its need for them soars.

Areas formerly prioritised for protection—including native American forest—are being abandoned in times of high activity. And there will be more of these. Climate models augur a huge increase in wildfires’ frequency and range. Yet with many politicians on the right denying the reality of global warming, no government or agency has made a serious effort to model what firefighting resources will be needed, to defend what areas and at what cost.

I looked around on the internet in the usual places and couldn’t easily find totals for different kinds of wildland firefighters through time, but I did find this article about California firefighters and the different places firefighters come from. I don’t know where the author got his information that “fracking and other extractive industries” were the competition for firefighter, and not, for example, the burgeoning wind and solar industry in the West.

Now it appears that a State with a D governor, that is, California, is taking action to increase the number of firefighters. But maybe CalFire hasn’t done what the author of the Lexington column thinks is appropriate future modelling. And if that’s the case, it’s not because he’s an R.

I had to sign up for The Economist and they sent me a welcome email.

Welcome to The Economist. I look forward to introducing you to our distinct blend of fact-filled reporting, mind-stretching analysis and elegant writing. Since 1843 we have been the voice of progress in politics, business, science and culture.

I guess it’s mind-stretching if you feel you need to research every claim made :).

I ran across these links to Canadian fire and forest info, and thought they were pretty interesting. You can break them down by province, source of ignition, and so on. Of course, everything from BC to PEI is in the combined statistics. I wonder what the data would show if it were arrayed as “forest fires of similar vegetation types across western North America? Maybe someone’s done that.

Here’s the link to the fire info in the Forestry Database (which has a variety of other interesting info, including forest products prices, that you can find from this dashboard).

Here’s a link to the Canadian National Fire Database. This shows some of the reports you can play with.

The USGS report calls new fuel breaks “a grand experiment” and says that there is very little scientific evidence—only anecdotal evidence—that they work.

It took me about two seconds to find this one.
Perhaps the report authors looked at it and decided observations of practitioners don’t count, even if summarized in a report. It’s pretty compelling to me, though. In fact, I would believe interviews with fire people more than calculations on data sets published in a journal. Here’s what the fire folks quoted say:

“The main theme fire managers expressed regarding fuel breaks is that they are not show stoppers. “You still have to show up to the fire,” said Lance Okeson, Boise District BLM Fuels AFMO. Fuel breaks are designed to work in conjunction with fire resources (e.g., engines, water tankers, etc.) to stop fires. In most situations fuel breaks alone will only reduce the rate of spread and intensity of a wildfire. It won’t put it
out, but it can greatly increase the chances of containing a fire and can dramatically reduce the size and severity of wildfires. Managers agreed that fuel breaks will not slow down head fires under extreme conditions, but will dramatically reduce the spread rate of a flaming front under normal conditions.

Back to the USGS report:

Firefighters recognize that fuel breaks are likely to do little to reduce a fire’s intensity, flame length or rate of spread under the extreme fire weather conditions that have caused wildfires to explode and quickly spread through the Great Basin in recent years, the report says.

“That is a limitation of fuel breaks—under severe fire weather conditions they’re not going to be effective because the intensity of those fires is such that they can jump right across fuel breaks and roads,” Douglas J. Shinneman, a USGS supervisory research fire ecologist in Idaho and lead author of the report, said in an interview.

It seems like that quote is a bit misleading in that it doesn’t mention the utility of fuelbreaks in helping with suppression. Which is exactly the main point, as the fire folks say in their report. Then we get to the old “it won’t work all the time, so we shouldn’t do it” argument.

The breaks could slow wildfire spread and are a logical idea given the increased wildfire threat, but they’d have to be regularly maintained, said J. Derek Scasta, an assistant professor and extension rangeland specialist in the Ecosystem Science and Management department at the University of Wyoming.

“It’s easy to create an overly ambitious plan that the human resources aren’t there to do it the way it should be done or the way we want them to be done,” he said. “There are big questions with fuel breaks, too. At this landscape-scale, how do we establish fuel breaks that are long enough, wide enough, enough in number to actually affect fires?”

If fuel breaks are ever proved effective against wildfire, they come with a tradeoff: Damaged habitat for species such as the greater sage grouse, Shinneman of the USGS said. The chicken-sized bird is an indicator species for the health of the sagebrush lands, which support hundreds of species of wildlife, according to the Fish and Wildlife Service.

In building fuel breaks, “ideally we will reduce wildfire, or at least the risk of wildfire, but at the same time, there’s going to be potentially negative impacts from additional disturbance of the fuel breaks themselves, and it can be argued that that’s the lesser of the two evils,” Shinneman said.

The BLM considers the area where the fuel breaks may be built already disturbed because they’ll parallel existing roads or other rights of way, said Ken Frederick, a spokesman for the BLM’s National Interagency Fire Center.

This includes the “they won’t work if we can’t afford to keep them up” argument (but it also raises the question of whether they can afford to do them in the first place). Also the “they work but not at the landscape scale” this is confusing, I’d have asked Scasta more about that.

‘Conveyor Belt’ For Fire
The fuel breaks promote the spread of invasive grasses and other non-native species, which can take over large swaths of land and increase the risk that wildfires will spread, not slow down when hit the fuel breaks, said Meg Krawchuk, a scientist who studies landscape fire and conservation science at Oregon State University.

“They carry fire very fast, very quickly,” Krawchuk said, referring to fuel breaks covered with invasive plant species. “You end up with a conveyor belt for fire in these grasses.”

Fuel breaks also fragment wildlife habitat and damage ecosystems—especially from the use of chemicals and earth-moving machines the BLM expects to use to clear the fuel breaks, said Erica Newman, a researcher studying the ecological effects of wildfire and other landscape disturbances at the University of Arizona.

“One of the big rules of ecology that we know is that species do not survive in fragmented habitat,” Newman said. “They’re talking about an ineffective tool to fight fire, and it’s going to fragment habitat. They’re going to raise fire risk and further endanger biodiversity. Their reason for doing this is not sound.”

“I have never heard any scientific basis for fuel breaks,” Newman said. “They’re obscuring science rather than employing it to do their research. This looks like a giveaway to the chemical and machinery corporations.”

My bold. That’s a pretty strong statement as quoted.. not for any fuel breaks anywhere ever? And those fire folks who authored the piece above have ulterior motives? Note the presentation by Fettic linked under the photo, he seems to be aware of sage grouse and their habitat.

I thought this paper was interesting because the authors directly measured trees, and took photos of the studied stands, which really gives a reader a feel for the study.  Here’s  a link to the paper itself, and here as described in ScienceDirect.

Highlights

•Large trees and shade intolerant trees had a higher probability of surviving fire.

•Radial growth in small trees in burned stands increased.

•Radial growth in large trees remained suppressed for decades after fire.

•Radial growth responses can be explained by changes in leaf area.

•Smaller trees easily add leaf area following fire while larger trees often do not.

These all make sense, in my experience.  We used to have the concept of “release” in silviculture. The idea is that if you remove competing trees, sometimes the released tree will grow and thrive, and sometimes it will just sit there or “not release.”  It sounds like the large trees may have been old, and some old trees don’t release.  Trees don’t release for a variety of reasons, depending on species, age and other factors which  silviculturists and silviculture researchers have spent a great deal of time thinking about. Maybe someone can weigh in who knows the studied area, species, etc.?

I think one of points that the authors are making is that one fire severity index measurement can’t really explain what you need to know about trees. If you want to know about stands of trees post-fire, you should measure stands of trees post-fire.

The results we present suggest that fire severity alters forest stand structure not only through mortality but also via individual tree physiological responses. Slower growth in residual trees that results from fire damage may render these trees more vulnerable to mortality in the face of additional stressors (Cailleret et al., 2016; van Mantgem et al., 2003).

We believe it is most likely that fire has a more pronounced longterm effect on radial growth of tall-statured and large diameter trees than smaller trees because recovery of a tree’s leaf area following disturbance is achieved primarily through height growth and the addition of new branches. Large trees at or near their maximum height potential have limited capacity to recover in this fashion, instead relying on the creation of epicormic branches and more complex crown structures to add leaf area without exceeding the tensile strength of the water columns (Van Pelt and Sillett, 2008; Ishii and Ford, 2001; Waring et al.,1982). This has important implications for wildlife species reliant on complex crown or branch structure for nesting, such as northern spotted owl or marbled murrelet (Bond et al., 2009; Ritchie, 1988; Franklin et al., 1981). Fire disturbance may be an important mechanism for creating these features and the persistence of these species in the Pacific Northwest (Fig. 9)

Although we show that MTBS severity classifications are associated with distinctive tree-scale effects, the differential response to fire of trees of different sizes and species suggests that it is important to contextualize field measured or satellite-derived severity metrics by forest structural and compositional attributes. The same fire severity as measured by standard indexes may have different implications for
future forest dynamics depending on residual tree structure and composition. Fire intensity and individual tree resistance drive residual tree structure and composition following fire. As we continue to develop heuristics and management strategies based on fire severity maps, it becomes increasingly important that we find ways to quantify pre-fire forest structure to better understand the future trajectory of forests following disturbance.