Essays

Wild On The Prairie: Habitats

Fire as a determinant in aridlands ecology
June 1, 2001

A recent trend in politically correct interaction with nature is Low-impact Camping. In this philosophy a campfire is an evil thing, something sure to scar the land. On the Llano Estacado fire was once a major determinant of the regional ecology. Fire is an agent of change, part of the natural cycle of an ever-changing landscape. After a fire the grass is greener than before. The dead stalks and any woody invasive shrubbery are removed. Grass needs fire, not only for fertilization, but also as a purifier and cleanser. A campfire is a symbol of its ecological role. A campfire can be a prayer and perceived as a sacred act.

After I build a campfire and leave, there is no trace left behind. I place the fire where the most constant change in that ecosystem occurs. In the places where I camp, most watercourses are dry. A gravel or sand streambed is a place of abrupt and violent change. Obliteration of disturbances in the sand or gravel will come, sooner or later. (Now, of course, I don’t CAMP in the watercourse. I am not that stupid!)

The movement of the flames in a campfire, and the heat released, innately focuses the human mind, quietening thought. Fire induces a contemplative state. It is a prayer with form. The ever-changing shapes of the flames tell stories.

Newly green grass, post-fire, is more nutritious to grazers than old grass riddled with unrecycled dead clumps. Bunchgrasses grow out from a center that slowly dies. Fire separates the outer ring from the old center, and new clumps are created.

The timing of a grassfire influences the floral diversity of each habitat it touches. On the buffalo prairie winter and spring fires kill the annual herb seedlings, thereby reducing competition for the grass species, which come back strongly with rainfall. Summer and fall fires clean the ground, so the annuals have sunlight and space in which to flourish. The results vary with rainfall.

Most of the rhizomatous perennials benefit from the fall fires. The soil of the prairie has a buried network of the roots of rhizomatous perennials, each waiting for disturbance so they can do their job. Such perennials pop up soon, to partially cover the ground, so when the winds of spring come there is less wind erosion. If the ground becomes bare-- bulldozers, floods, and fire are all the same -- for any reason, these plants appear.

Broomweed explodes from the touch of the merest flame. Old grass fields, deteriorating ungrazed and unburnt, slowly fill with broomweed. When lightning strikes, the broomweed maintains the pure heat of the lightning, so the fire can successfully reshape the landscape. Near my duckhunting camp on the salty rim of the Pecos river my older goddaughter and I gathered plants to burn, after noticing Salt Cedar (Tamarix sp) burning with a green iridescence. Not once did plants combust as thoroughly as they do in grassfires. The campfire was not hot enough. Even the broomweed did not burn as thoroughly. The dead yucca leaves did not ignite at all. Why does a grassfire burn so hot?

I have been around a few grass and brushfires, for various reasons. Most of the time I possessed an adversarial attitude, meaning that it was in my interest to put it out. A couple of times I was worried about human structures getting torched, and another time I arrived as the firefighters did, so I helped in small ways. However, one time I able to observe a fire unencumbered by such prejudice.

I was in the foothills of the mountains I visit when I seek solutions, solitude, or silliness. A column of smoke, appearing to be a hundred yards in radius, began dominating the sky, shadowing my peaceful noontime siesta. I quickly jumped in my truck and drove over the hill. As I neared the flames another pickup appeared - the local rancher. Barely giving the fire a glance he pulled up beside me and told me that he was driving to the nearest phone (over 15 miles of gravel road) to call for the volunteer fire fighters “Don’t bother to try to put it out – there are no cows in this pasture! I got metal fence posts, too.”

The fire approached the road in front of me, widening as it floated on the wind. Flames from the grass burned three feet high, while broomweed flames leapt six feet, and shrubs seemed to disintegrate with the touch of the flames (except for junipers which became house sized torches).

Hawks appeared, one by one, swooping around the column of smoke and gliding in with great style, to land on the blackened prairie. They cocked their heads, watching and listening for injured mice. Some caught their tiny agonized prey with a quick flap and pounce, while one merely walked up to a tortuously twisting rodent and contemplated its misery. Three shrikes began patrolling the lead edge of the fire, waiting for the opportunity to surprise panicked sparrows. Even a Vulture showed, but he stayed circling high, refusing to come down for anything smaller than a rabbit. It did come down, eventually, and more buzzards drifted in for an inspection tour.

The fire reached the road, which stopped its advance. I walked along where the flames were dying. Smoldering grasshoppers kicked on the tarmac. Drifts of smoke crested over the road where a bush still smoldered. The fire slowly crept down the side of the road. I suppose I should have put it out - I probably could have, but I did not even think, too entranced in observation.

The fire finally reached the draw bottom, filled with bluestem grass upstream from the roadfill. When that caught fire, the wind also gave a gusty puff, and a burning tumbleweed from the road’s edge was given a push strong enough to cross the road.

Thunder rumbled. Only puffy cumulus clouds had graced lunch. The smoke, angling slightly forward of the flames had streamed upward. The smoke’s particles must have caused a slight change in the local air -- triggering the formation of the thunderhead.

I turned around, to walk back to my truck. A kingbird walked around picking up grasshoppers. A brave lizard performed in tandem with the kingbird, both gathering mouthfuls and stopping and working hard trying to force themselves beyond satiety. A Trans-Pecos Rat Snake slithered along the edge of the road, and stopped when he found a dying mouse. What the heck was he doing out in the daylight? Had he been chased from an aboveground siesta?

After forty minutes I began to hear firefighting sirens. Where the fire had crossed the road the flames were building up strength again. In the burned areas hot spots flared; tree form yuccas now smoldering torches, old standing deadwood junipers slowly falling over as fire diminished them, slowly disintegrating like incense sticks.

I drove off, to my campsite for the night, another twenty miles down a gravelly rutty road. After I left my camp two days later, I learned that the fire had burned two sections (square miles) of the local juniper/oak Sierra Madrean ecotype.