Well, I watched the Nova program.
Although I had high hopes (the scientific research being done, as presented in the program, I found particularly interesting), overall I found the program incomplete, too brief, simplistic, and ultimately disappointing.
Why do I feel this way?
The three major California fires referenced in this program - the Camp Fire, the Tubbs Fire, and the Carr Fire - started, and mostly burned, in chaparral scrub land, and
not in "forests" per se (tall conifer forests, as defined by the program).
Although I might have missed it, I don't think I heard the word "chaparral" mentioned even once. Dense, uncontrolled growth of chaparral here is one of the primary reasons California fires are so destructive.
Remember the bit in the program about the massive "fire tornado" they showed whirling around in the Carr Fire (Redding, Ca.)? That wasn't tall forest conifers burning, that was chaparral (I live fairly near Redding, so know it well). Redding isn't in the mountains (conifer tree country), it is in the Central Valley (chaparral country).
I am putting a bit of what I wrote on the "Fire Near Anne" thread (this part is from page 7 of that thread) below my signature, should anyone be interested. I talk a little bit about our weather here, and California's problem with chaparral. One thing that
was mentioned (again, in reference to conifer forests) was that thinning must be done frequently for it to be effective. Because thinned and cleared areas just sprout new vegetation.
This continual "thinning" needs also to be done with chaparral scrub lands. The problem being, chaparral is
much more difficult to thin, grows back
much more quickly than do conifers (so needs to be "thinned" more frequently), and -
and this is the main kicker - "thinned" chaparral has
no economic value for resale. Whereas conifers, even quite small ones (think treated fence posts), can be cut as part of a thinning process, and then sold.
Can I see the logging companies here lining up to get their permits to "thin" tall-tree conifer forests?
Absolutely. Can I see the same companies lining up to get out there and thin the chaparral?
Never happen.
So long as one major causal element of the California wildfire problem is ignored (chaparral), it is highly unlikely that any real solution will ever be found.
Just my 2cents.
Anne
This is my repeated post from the other thread:
I am sure that many of you have read about the recent fires here burning over "dry grass and chaparral". This really doesn't sound so bad, does it?
No, it really doesn't. That is, if one only thinks of "dry grass" as something ankle high that one might easily walk through, and might be thinking of chaparral as some kind of low-to-the-ground bushes scattered randomly here and there.
The reality is quite different. Dry grass here, particularly in the lower foothills of the Sierra close to the area where I live, can be in vast stretches, going on for many miles, and many thousands, or even hundreds of thousands, of acres. This grass turns the state an emerald green in the springtime, after the winter rains have done their work, but in the summer months this grass can become so dry that it will shatter, rather than bend, when one walks though it.
The grass in these stretches, particularly if it is not grazed by livestock, usually grows to be four or five feet tall (or even six, depending on the amount of rain that it has received). It can grow so thickly that someone walking next to you through this grass, maybe just five or ten feet away, cannot be seen. The grass grows that thick.
And what, exactly, is "chaparral", anyway? Chaparral is a mixture of woody plant species, with the mix varying between areas. In my area chaparral is comprised primarily of manzanita, a dense, woody, hardwood shrub. That doesn't sound so bad either, does it?
Manzanita in my area (in the foothills) generally can grow up to twenty feet tall, in dense, impermeable, thickets, that (like the grass mentioned above) can go on for many miles, and hundreds or thousands of acres.
One cannot walk through an established manzanita thicket. The branches of the shrubs can be large (three or four inches in diameter - or more), the branches are very hard (manzanita is considered a hardwood) and inflexible, and these branches become inter-twined, creating an impermeable barrier.
Manzanita is not easily cleared by use of a chainsaw (manzanita does not "fall" like a tree does, because it is just basically a very large bush). To clear manzanita requires heavy equipment (think bulldozer or caterpillar) and a LOT of patience.
Manzanita is is often used for firewood here, because it is so readily available when one lives in the foothills, and so very flammable that it can be used for kindling to start a fire in one's woodstove, even when it is still "green" and unseasoned. One does not use manzanita in one's woodstove once the fire has been started - manzanita burns very hot, and very fast - and has been known to start more than one chimney fire here. Turning down the damper on one's woodstove (to slow the burn), while burning manzanita, does not always have the desired effect.
Another factoid is this: manzanita has so evolved in our fire-prone areas, that it's seed needs fire to germinate.
U.S. Forest Service: "Germination: Common manzanita seeds are dormant and germinate readily after fire breaks seed dormancy"
https://www.fs.fed.us/database/feis/plants/shrub/arcman/all.html
There are many other plant species in chaparral as well, including scrub oak. Almost all plant species native to California are evolved to co-exist with fire. Scrub oak is also evolved to withstand hot and dry temperatures, and is also extremely flammable when it comes into contact with wildland fire. The word "chaparral" is derived from the Spanish word for scrub oak, "chaparro".
LOL. California Ecology 101. Sorry about that!
In any case, these kinds of conditions, and these kinds of plant ecologies, exist in a great many parts of the state, over vast areas. There are 33 million acres of wildland in the state. The problem we have here are not "forest fires" per se, but rather "urban-interface wildfires", where urban development (even small towns) have encroached into grass and chaparral wildlands.
The natural ecology, and the native plant species here, have evolved, over millennia, around the natural occurrence of wildfire.
Human communities, our homes and our structures - not so much.