Before we start looking at press coverage, we need to list all the possible causes of worseness. Ideally, an article would say “fires are worse as defined by this criterion” and “causes for worseness are complex, and these are the factors that may be involved.” Right now I’d like to ask for help in making a complete list of these factors. Granted, it’s made more difficult by vagueness on what exactly is meant by “worseness” but still, I think we can take a stab at it. Here are a few that I’ve picked up:
1. Past Fire Suppression
2. Drought, and heat or combinations of the above (some proportion x, of which is climate change) both as they impact
a) fuel conditions
b) suppression activities
3. Increased length of fire season (some proportion x of which is climate change, but various 2nd order causes, including other climate patterns, more human ignitions, changes in species, and so on)
4. Non-native species with different fire-related characteristics than previous occupants of the landscape.
5. Changes in native fuels (e.g. more dead trees or changes in canopy structure or species composition??)
6. More people living in the WUI (so infrastructure needs protection)
7. Tourism is more important economically, but smoke and closures impact that.
8. More people living and visiting the woods means more human-caused ignitions.
Suppression Management and Policy
9. Changes in policy (WFU), strategies and tactics.
I became more aware of 4 recently due to an article in New Scientist here. But there are many other articles around.
INVASIVE species of grass are making wildfires in the US up to twice as large and three times as frequent.
One species, cheatgrass, is now widespread in California and was involved in last year’s Thomas Fire, the largest recorded in the state until the Mendocino Complex Fire now burning (see Converted 747 flies to the rescue in battling California’s giant fire).
Like cheatgrass, many of the invaders are finer than native species, and so ignite more easily, and occupy space within and between patches of native grass. Other invaders, such as silk reed, grow more than 3 metres high and can spread fire into trees.
Emily Fusco at the University of Massachusetts in Amherst presented preliminary results of her study last week in New Orleans at the annual meeting of the Ecological Society of America. She analysed the impact of nine widespread alien grasses in areas of the US they have invaded.
Fusco combined this information with ground and satellite fire records, comparing fire frequency and size in infested habitats versus comparable but uninvaded habitats. She found all the invasive species except one made fires more frequent, and all but two made fires larger.
There are also different potential causes for some of the factors listed above. For example, non-Native species extending the fire season as in this NPR story.
Jeanne Chambers of the U.S. Forest Service is another combatant in the war on cheatgrass. She says in Nevada, they’re seeing fires burning as late as November and as early as January.
“That really has never happened in the past. When we have dry conditions and we have cheatgrass in the understory, we have fuels that can allow those fires to burn almost any time of the year.”
But back to my list, does anyone have other “worseness causes” to add?