Friday, November 07, 2014

Unexpected Big-ass "Forest Fire"

It was becoming a beautiful day. The prediction had been for damp and cold, but the actual weather looked increasingly great. I spread an alert through the new Somme 2030 stewards. "Anyone free to do some planning, exploration, and loving the ecosystem, before the cold comes?"

Part of our thought was that it might be the perfect day to find and mark (and protect from slaughter) a beautiful little viburnum tree called black haw. This could be important, because the new mission of Somme 2030 (also called the "Somme Revival Party") was to restore 150 acres of rare oak woodland and wetland habitat, and most efforts fail when it comes to the plum trees, hazelnuts, and black haws that may have been a crucial part of the habitat.

Would anyone be free at the last minute? It turns out that Travis had already scheduled a day off - and both Michael and Josh managed to wiggle out of whatever, and now we four assembled in the wilderness of Somme East to plan the future.

We weren't expecting drama today. Josh, Michael, Travis and I searched for seedlings
of rare understory trees that might become important habitat by the year 2030. 

Why do haw, plum, and hazelnut need help? First, because they've been nearly obliterated by the shade of invasive trees (from buckthorn to maple) that - in the absence of fire - destroy the richness of the oak woodlands. Second, because now that we're starting to restore the habitat, our controlled burns will also unfortunately kill the few native shrubs that survive. And last, because eager-to-be-helpful brush cutters will snip them if they're not marked, when they cut the buckthorn.

Oh, they may not look like much now, but the color of those two surviving leaves give away a patch of one- to four-foot-tall black haw sprouts, scattered over an area the size of a house. If protected, this shrub thicket could be twenty feet tall by 2030. It could bear the nests of blue-winged warblers, eastern towhees, black-billed cuckoos and other now-rare birds that once helped the woods to thrive.

The blue-black fruits 
of the haw (on their bright red stems) would once again be eagerly devoured, in the words of Donald Culross Peattie, by "gray foxes, white-tailed deer, bobwhites, wood-wandering boys, and botanists." (But why do wood-wantering girls get left out?)

When we'd find a patch of black haw, we'd record the location on cell phone GPS, tie ribbons on the young trunks (so lopper-wielding brush cutters could avoid them) and rake leaves away - because - we hoped - if all went well - this whole area would soon be treated to a prescribed burn by Forest Preserve staff or contractors. 

Did we really think that would happen? Sure, we'd made the request earlier this fall. Forest preserve restoration has indeed been getting better and better. But we've also been disappointed. And this large area has never been burned since the days of the bison and the Potawatomi. 

That's when the miracle happened. We were intent, focused, thinking through plans, tying ribbons, raking leaves - and having a harder and harder time hearing each other's voices - because distant trucks or trains or some ungodly noise was getting louder and louder. Suddenly Travis said, "Leaf blower!"

Really? Out in the middle of the forest? Two of us immediately knew what that meant. Staff were making fire breaks, right where we'd hoped. At first we assumed the breaks were being prepared for another day. But then we saw growing billows of smoke. What serendipity! It was happening now!

Before we knew it, we were being treated to the drama of a Forest Preserve on fire. 

Many people might think perhaps we'd be scared. But a woods fire on a calm day like this moves at the speed of a very ill patient with a walker. The average person could crawl out of the way. You could hop over it. You could walk through it, stepping briefly right in the flames for that matter, if you were wearing clothes and footwear not made of petroleum. Not that anyone would recommend it. But the level of danger is trivial. Don't lie down in the flames, and you're okay. (On the other hand, don't try the "walking through fire" trick with "synthetics." Some melt. Some burn.)

How about the worry that the fire will "get out of control" and burn down buildings? Here we can first look at the record. All the region's conservation agencies burn their prairies and oaks woods, and no fire has escaped to burn down buildings. The reasons are simple. Competence and firebreaks.

Before the burn was lit, those leaf blowers emptied a narrow strip of soil of any flammable leaves, wood, or anything else.
In the photo on the left you can barely see the leaf-blown area to the right of the black. But look how effective it was.

It works because the person spreading the fire starts it right on that edge, and other crew with water backpack pumps are carefully watching to make sure no hint of flame tries to sneak across.

Once the fire has burned a few feet in, leaving behind a black area of no fuel, the woods outside the break are safe.

Notice the little flames moving left in the photo. The farther they get, the safer the area outside the break.

(On the other hand, "don't try this at home." There are many dangers that are not obvious to the untrained. Only people with extensive training and expertise can do controlled burns.)

Perhaps this is the time to consider the "cost" or "harm" of such a fire - compared to the benefits. People with respiratory problems should stay out of the smoke, but they could just walk away. Air pollution is indeed a cost. We'd all prefer no air pollution, but we degrade the air by driving our cars (or taking the bus or train). We increase carbon dioxide in the atmosphere every time we breathe. We put particulates in the air every time we have a cook-out or burn a fire in a fireplace. We as a culture have decided that some benefits outweigh some costs.

In this case, the benefits accrue to ecosystem services performed for the planet by healthy woods, and biodiversity conservation, and recreation. It used to be that the natural lands of the Cook County Forest Preserves were treasured for recreation by hikers, artists, photographers, birders, foragers, and kids of all ages. It used to be that these 55,000 acres cleaned our urban air throughout the growing season ("the lungs of the city"). It used to be that the ecosystem preserved the soil from erosion and sponged up rain to mitigate floods.

Insidiously, "invasive" or "malignant" species began progressively to destroy all these values. Only in recent decades have we gradually come to understand that an impenetrable thorn thicket where an open woodland used to be was not "nature" or "natural" or good. Fire restores the plant community, animal habitat, and ecosystem services.

Small buckthorns (the nasty saplings here with green leaves) bite the dust.

The most obvious benefit is the control of buckthorn. This small tree - in the absence of fire - destroys animal habitat and shades out the grasses and wildflowers so severely that even the soil erodes off and clogs streams, lakes, and ultimately the Gulf of Mexico. After this fire, not only will the buckthorn be reduced, but the thick mat of leaves will uncover the soil just long enough to seed. Right away Travis, Michael, Josh and the rest of the Somme Revival Party will plant the rare seeds they've been gathering all summer and fall. Next spring they'll sprout in perfect conditions. Healing has begun.

If you checked out the Somme Facebook page, you might have seen the video of this fire in which 
burn boss Evan Barker seems to be walking through the woods spreading fire at random. That too deserves comment.

Carefully placed strip fires do what was once done by a mighty wind. 

For millions of years, grasslands and oak woodlands burned from fires ignited by lightning. Most of the grasses, leaves, and dead trees were then burned by fires spreading with the wind on the very driest, hottest, windiest days. Considering how slowly today's tamer fires are spreading, large areas like Somme east (150 acres) would have to burn for days if a single fire were to spread slowly on its own. So a drip torch is used to start new lines of flame, back and forth through all the key areas. This fire will spread in out in both directions, burning the leaf litter (and many invasives) from the entire area of this photo in ten or fifteen minutes.

Wonderful day. Now we approach about the future with greater hope and confidence.

Oak woodland in Somme Prairie Grove after decades of restoration.

What comes next? First finish gathering, and then broadcasting, all that crucial seed.
Then cutting bigger brush and burning it in bonfires throughout the cold winter.
Then more study, planning, and month to month of rewarding stewardship in the beautiful and recovering Somme Woods (inspired in part by the pilot work to the west in Somme Prairie Grove).
A worthy, wonderful, and generous dream.
Whether you end up calling yourselves Somme 2030 or the Somme Revival Party or whatever ...
... thank you and best of wishes in your noble quest. 

Tuesday, November 04, 2014

Fall Burn - Somme Prairie - November 2, 2014

Every year, one day is most important to a prairie - bar none.
That's the day it burns.

Fire is so important to ecosystem sustainability that "evolutionists pray for it."

Usually a burn is planned for about half of each of the three Somme restoration areas. The principle is that half is left unburned as habitat for rare animals that may be sensitive to fire.

This year was the time for the west half of Somme Prairie to burn, and that's where we'll look next year for all the rarest plants to do best - for the richest wildflower displays and most butterflies. That's where we'll see wholesale reduction of some invasives and the best advances in diversity and health.

Burns are good.
Preparing the fire break
The fuel is cut and blown out of the break by leaf blowers. The whole process is carefully planned and carried out.

A modest fire
On somewhat of a cool and damp day, this fire through average to light fuels was easy to control - yet making life and death difference for the plants and animals of the prairie. (These first two photos courtesy of Troy Showerman, burn boss for the fire. Troy, thanks a little for the photos - and a huge massive lot for the burn.)

Happy crew when the burn is done. This is actually the crew that burned Black Partridge Woods.
The burn program has many crews out across the county on every good burn day.
This photo from FP burn boss John McCabe.
The next photos were taken on the following day - the black aftermath. The quick fire may be colorful and dramatic, but what counts is the long-term work the fire does.
Sedge meadow - only the upper layers burned in damp areas like this. 
In the sedge meadow, above, if you kicked at the char, you'd find that a couple of inches of unburned vegetation survives under the black in many places. Some people argue that the best plan is to burn the whole site every year under moderate conditions in fall. You can see how that might work in this photo. Their argument is that plenty of habitat for rare animals survives in unburned vegetation or just "randomly" missed patches, also seen above. Most land managers recommend: burn half; leave half unburned.

Here we see a shrub patch that the fire has top-killed. The invasive dogwood shrub would destroy the prairie by its shade without fires. The dogwood will re-sprout from the bottom next spring. But it has lost its edge, and frequent burns in some parts of this site have demonstrated that the high quality prairie can completely out-compete the dogwood if the burns are frequent.

Burns reveal the structure of the ecosystem - like an X-ray. Here at the edge of the sedge meadow, vole tunnels can be seen running from the tall grass into the drier dogwood thicket. Before the burn, the vole tunnels (foreground) were invisible. Only the sharp-nosed coyotes knew where they were. Now we see them everywhere.

Another "X-ray." The white clumps are recent excavations of sub-soil from crayfish burrows. This shot in from the highest, driest ground on the site. But the ancient crustaceans are tunneling from the water-table to the surface everywhere.

Upland "high quality" prairie. Some patches had too little fuel to burn. This is tallgrass prairie?
The photo above shows an area that the Illinois Natural Areas Inventory (1970s) rated as "high quality" (Grade B) prairie. (Grade A = "very high quality.") It has diverse conservative species but not Grade A structure. The assumption was that this area had been subjected to excessive grazing by cattle or horses at some point - but that with Grade A prairie right near by, it would recover on its own in time.  Yet after three decades of burning every couple of years, it doesn't look all that much better. Perhaps it needs seed restoration with some of the taller conservatives, like dropseed grass, prairie clover, and others, the seed of which "don't get around much anymore," by itself.

A firebreak - neatly raked.
Prior to the burn, the crew mowed and raked a firebreak through the center of the site. The burn is started as a backfire, so it burns slowly away from the downwind edge of the intended unburned area. Fire does not burn one foot beyond where it's supposed to.

Meadow vole trails, diggings, and tunnel entrances. 
Now we can see the under-the-grasses architecture of our little hamster-like, gerbil-like meadow voles. Their otherwise invisible influence is massive. Although they're the main food of coyotes, red-tailed hawks, and many other predators, some people speculate that voles are a lot more common than they used to be. They seem to destroy all the seed of some conservative species every year. Perhaps an unbalance has been created by the loss of other predators (for example weasels, big snakes, short-eared and long-eared owls). Or could it be that the problem is that we leave voles half the site to hide in after the burn? Perhaps they were less common when the burn patches were bigger?

Wet thickets don't burn on most years.
Another concern of many ecologists is the loss of the shrub communities in prairies, savannas, and oak woods. This thicket of dogwoods and willows won't burn unless there's a fire during very dry times. These wet shrub thickets seem crucial for some rare birds and other animals.

In the northwest corner of the prairie is a large area that is shrubby throughout. If left alone, these little shrubs would grow up and wipe out all prairie plants and animals. With regular burns and seeding with more diverse conservative plants, the prairie will win. It's a long process and needs the help of many stewards, but it's worth it to restore size and quality to at least a few fine eastern tallgrass prairies, which otherwise would be gone from the Earth, with all their biodiversity.

Where the shrubs are biggest and densest, the fire goes out. 
As they grow annually larger in the absence of fires, dogwood thickets kill the grass and wildflowers, the dried remains of which fuel the prairie's health-restoring fires. Once the shrubs get this big, they can be removed only by "catastrophic" fires under extreme conditions - or the laborious work of people like you and me. Frequent fire is the better option.

Unburned. High quality. 
Here's what a piece of the unburned eastern section looks like. The fine low grass is the conservative prairie dropseed. The green patch in the lower left middle is a young buckthorn. Without fire, in time it would destroy the whole ecosystem.

Prairie plants rejoicing after a burn
And because a clear vision of process and potential is crucial to understanding and caring for the prairie, here's what Somme will look like at the height of next summer. We burn the prairie for hope, happiness, and the future.