High Plains drift (North Texas)

American historiography also has its dryline.  Since John Wesley Powell published his justly celebrated Arid Lands report in 1878, the line at which annual rainfall drops below the level needed for dry farming has been taken as the divide between eastern and western landscapes.  The grasslands appeared earlier and demanded a variety of innovations for fencing, fuel, plowing, and shelter; but not until a stubborn aridity denied the old crops – roughly along the 98th meridian (usually rounded to 100th) – did western settlement stumble and halt.  East of that line trees could grow if fire was kept out.  West of the line, trees too faltered and grasses replaced them.  Crops required irrigating, and herding made more sense than farming.  This climatic divide became a settlement divide, and is a major reason the bulk of public lands fall reside in the west.  The line traced a meridian of historiography as well.

What is true for the Plains generally is certainly true for Texas as well (this is the baseline thesis for Walter Prescott Webb’s The Great Plains).  The dryline meridian arcs along the Balcones faultline, and it defined the line of settlement under a broadly southern model until after the Civil War.  Before then aridity, hostile Apaches, Kiowas, and Comanches, and a sparse population made the arid plains the frontier.  One might also add wildfire to those settlement inhibitors since it was as endemic to the region as prairie dogs and grama grass and was capable of propagating at rates and breadths unknown in the piney woods.

The fires burned widely and routinely in an immense choreography between climate, grass, a massive menagerie of grazers, and fire, all loosely staged by the alpha creatures, humans, who also happened to hold a species monopoly over ignition.  The details are unclear, and were in any event still adjusting since the adoption of the horse by Plains peoples less than a century before and the resulting internecine conflict over territory.  But there is little reason to doubt that similar relationships to what Surveyor-General Major Thomas Mitchell wrote concerning Australia at the same time also held for fire, grass, and bison, and human inhabitants on the southern Plains.

Fire, grass, and kangaroos, and human inhabitants, seem all dependent on each other for existence in Australia; for any one of these being wanting, the others could no longer continue.  Fire is necessary to burn the grass, and form those open forests, in which we find the large forest-kangaroo; the native applies that fire to the grass at certain seasons, in order that a young green crop may subsequently spring up, and so attract and enable him to kill or take the kangaroo with nets.  In summer, the burning of long grass also discloses vermin, birds’ nests, etc., on which the females and children, who chiefly burn the grass, feed.

Unsurprisingly, America’s aboriginal peoples referred to free-ranging fire as the “red buffalo.”[i]

The longer the fetch of grass and wind, the vaster the fire.  Accounts from the late 19th century report burns of several million acres.  By then the old choreography was breaking down as the mounted aborigines were swept away, the bison driven to extinction, routine fire-setting banned, and the geography of combustibles fractured into fields, pastures, and roads, and no longer joined by subcontinental migrations of grazers, hunters, and herders.  But where those elements endured, or were recreated, there might be nothing to stop a running fire fed by grasses from a wet rainy season other than wide rivers, swathes eaten out or trampled by bison throngs, the occasional arroyo, or a soil-cracking drought that shriveled the combustible grasses before they could carry flame.

 

§  After the Civil War the rush of settlement resumed.  It boiled out primarily from the Hill Country as hybid cattle and hybrid herding, a mestizo fusion of southern and Mexican practices, pushed into fresh territory.  The process assumed the form of a colossal swap as Texans replaced Comanche; longhorns, bison; and cattle drives northward, the seasonal migration of the southern herds.  The upshot was a less controlled mixed of fires – a fast-morphing regime – but one that still left fire on the landscape.  A prairie fire remained a threat; but fire was also recognized, if timed properly, as a means to green up forage and retard wildfire.

The era lasted only a couple of decades.  The fertile sites were gradually plowed into cotton and alfalfa.  The open range was fenced into pastures.  The grass was grazed to nubbin.  The longhorns were left feral in remote canyons while improved breeding replaced droving with something like husbandry.  But the droving era left behind more than popular songs and Hollywood celluloid.  It repeated the tragedy of all pioneering: it changed the conditions that had made it possible.  Its creatures, its lands, the choreography that organized them into patterns – all went.

The spoor of the droving era contained the seeds, literally, of a new landscape.  The cattle trails tracked what Texans came to call “brush” – cedar around the Hill Country, juniper to the west, creosote in the south, and mesquite generally but especially to the north.  Eating mesquite seeds, scarifying them through the digestive track, and then defecating them in manure piles atop the trampled soil created an ideal scenario to propagate a woodland from small enclaves onto vast swathes of north, central, and west Texas.  The woody species are several, but all are sensitive to fire in their initial year or two, and some, like redberry juniper, remain vulnerable for up to eight years.  Likely the trees had always been around, though only in fire-free niches among rocky outcrops and east-side riparian patches (downwind of barriers).  The cattle carried then north and west, not only spreading seed but cropping away the fires that might flush seedlings from the scene.  As fire became rarer, surviving brush became more common.[ii]

Once rooted, fire alone could remove only a few species.  While a stiff burn might top-kill a fraction of the others, primarily sprouters, it could not uproot them, and they regrew like hydras.  Mesquite, in particular, thrived.  It naturalized among the new fire regime – one it had helped create.  Once they achieved a critical mass the trees could self-propagate.  They spread like a slow plague.  What had been identified at the time of European contact as grasslands shape-shifted into brushlands.  A new, self-perpetuating community of trees, grasses, browsers, and grazers coalesced; what cattle had began, other seed-feeders continued.  Unless cut back, poisoned, or uprooted, the brush remade the grassland into a savanna, and then into a woods.  Texas ranchers have been trying ever since to expunge them, without success.[iii]

 

§ Most of what is known about fire ecology in Texas comes from elsewhere.  Its eastern forests are studied as a subfield of the southern pineries.  Its grasslands are mostly known from research in Kansas and Oklahoma, and this includes the dynamics of encroachment by eastern red cedar.  Its coastal marshlands extend those that fringe the well-investigated Gulf.  Even the Chihuahuan Desert is better researched in New Mexico.  But in one area Texas stands nearly alone.  It is a world center for the relationship between fire and the varieties of brush that have come to infest the Texas landscape, particularly mesquite.

Fire and mesquite establishment, fire and mesquite-grass dynamics, fire and grazed pastures in mesquite woodlands, fire and mesquite control or outright eradication, and in recent years fire what might be termed the mesquite/urban interface – these have claimed the special attention of fire science in Texas and produced a world-class literature.  The what, why, and how of this research program speak volumes about the peculiar character of fire and its management under the flag of the Lone Star state.

The research might be better characterized as fire agronomy than fire ecology in that its funded purpose is not to advance fire science so much as to find ways to control or kill off mesquite and thus improve pasture.  The reductionist tendency of science lends itself perfectly to such purposes: it can isolate particular features and find ways to manipulate them in order to maximize productivity.  The ultimate outcome is not reckoned in ecological integrity or grassland restoration (new grasses may be introduced) or some other public good, but in economic wealth.  Sponsors hope fire will prove a cheap tool for brush clearing and that restored pasture will yield better fodder for more beef.

At issue is not the caliber of the science, which can be high, but its ability to transcend its context.  Most of the funding comes from local sources, primarily Texas A&M’s AgriLife Research Program.  Since only one research facility owns its study sites (Sonora), investigations take place on private land, with the permission of landowners and with care for their special interests.  This is state sponsorship for state-defined purposes.  Whether or not the discoveries generalize in either theory or geography is of less interest than whether they address the economic concerns of the sponsors.  Even when published in leading journals, the research struggles to cross the Red, the Sabine, and the Rio Grande.  Its researchers have the eyes of Texas upon them.  The basic formula, moreover, is a common one in Texas: public investment for private gain.

Mesquite is stubborn.  If you want to remove it, you treat it as Rome did Carthage:  burn, plow, and sow with salt.  Or in modern parlance, mechanically chop or (preferably) uproot it, spray it with herbicides, and when conditions permit burn it out.  Unfortunately, while fire is the most benign and cheapest method, by itself it is the least effective.  Like prairie bunch grass, mesquite has deep roots, resprouts readily, and thrives when burned.  Maybe a millennial drought and fire could deliver a one-two punch.  Otherwise, what a killing fire might do is delivered by machines powered by fossil fuels or poisons extracted from fossil biomass.  Both are expensive and require maintenance regimes.  An alternative strategy is to harvest the wood and burn it for bioenergy, which would help cover the cost of clearing.  Economics and ecology are out of sync because, in such a landscape, fire is a process for renewing rather than replacing the biota.

The most likely outcome is an accommodation.  Accept that mesquite has naturalized, like armadillos.  Control it so that useful grasses can still flourish and feed herds.  Unlike juniper, mesquite does not snuff out grass, nor does it, as juniper can, convert surface fires into convection-dominated conflagrations.  Rather, it shifts and mixes species, lessens the density of grasses, and complicates working with stock, but it can be lived with.  Where it becomes too encumbering, remove it by means that pay for themselves.  And where possible, use fire to refresh the landscape and encourage healthier grasses that can compete with brush.

 

§  Yet there is more to the story of mesquite as a parable of Texas fire.  The grasses that thrive in such soils and climates evolved with and still flourish with fire.  The system broke down because fire was removed, and it is breaking down again because fire is returning in feral avatars.  After being buried for so long, what accounts now for its zombie re-emergence?

This is a region, as Jim Ansley notes, ever latent with fire, always on the cusp of an outbreak.  Its tenacious grasses, its blustery weather, its knife-edge teetering between economics and ecology that determines how many cattle or deer are on the land and how many volunteers are available for a call-out – any can cause the landscape to veer into fire.  So far the concern has focused on wildfire, and apart from the usual suspects for causes observers point to reduced stocking because of persistent drought, a shift to hunting income in place of cattle sales, fallowing as a result of the federal Conservation Reserve Program, conversion to exurbs and ranchettes, and reductions in state support for VFDs, all of them economic considerations that translate into more combustibles.  It’s a slow drift that is enough to tip the scene into fire.[iv]

Behind such tinkerings, each minor but perhaps enough to trigger a big response, like a switch that turns on a dynamo, lies a larger notion that seems particularly suited to Texas’ obsession with its landed estate.  Fire, grazing, and grass work when there is abundant room, when there is ample space for land to burn, grass to grow, and land to lie fallow.  Herds move between the black and the green, and big herds and arid landscapes require lots of land to accommodate this migration.  Settlement first replaced bison with longhorns, then shattered that mobility by closing the range.  Ownership – the sanctity of private land – stayed within fences, and even the largest ranches barely had enough land to support the level of cattle they needed to generate the income they wanted.  The smaller ones had to move additional feed to the herds, or ship the herds elsewhere for a while.  A basic principle of fire ecology is, fire recycles.  In the case of grazing economies, the animals must cycle, too.  If wildfire takes out a significant fraction of winter range, the ranch will suffer and perhaps crash.  The usual Texas solution, substituting more land for intensive management, can’t apply.

An obvious solution is to burn off that surplus under controlled conditions, which would reduce the risk of wildfire and enhance the long-suffering grasses.  But fire management also requires intellectual and political space.  Fire must be seen not simply as a threat or a tool but as a useful process.  The tendency in Texas, however, has been to define it as bad because it threatens property and removes forage.  Instead, to prevent fire and promote beef, the default strategy has been to graze down to the point that fire can’t spread.  In a sense, settlers removed the grasses that sustained fires as they did the bison that supported Plains tribes.  While the productivity of the soil, of the system overall, may degrade, and may promote yet more brush, the immediate outcome is favorable, and in a landscape locked into boxes of individual lots, that is a rational economic choice that defers costs to future generations or to the public.

The paradox of course is that the same processes that are restoring bad fire underwrite the possible reintroduction of good fire.  At core, it requires surplus combustibles, which is to say, fallow, which is to say, land out of immediate production.  While the long term benefits might be healthy, it is the short-term cost that dominates the calculus of any but the largest landholder.  County judges and commissioners are quick to declare burn bans.  Many ranchers, particularly in the west, don’t want fire of any kind, except where it might remove brush, which in practical terms means combustion housed within engines that crush, shred, or extirpate.  To date the recovered and remade landscapes are fueling wild fire.  To what extent prescribed burns might substitute will decide what kind of fire regime will prevail in the future.

Public lands, or private lands used for public good, can make that transition easier because they can provide the requisite scale of operations, and they can absorb or internalize those immediate losses for longer term benefits.  They don’t have to mark ecological goods and services to market; they can invest at a social level for social amenities.  They have a public purpose in their charter.  Those lands needn’t be federal.  Texas has a robust complex of state parks that boast integrated fire management programs, complete with prescribed burning.  The tide doesn’t have to rise high, but something needs to float land use above the quotidian mean if it is to have enough political and ecological space in which to insert controlled fire.

 

Link to West of the Pecos (West Texas)


[i] T.L. Mitchell, Journal of an Expedition into the Interior of Tropical Australia (Lojndon, 1848), p. 306.  “Red buffalo” from Julie Courtwright, Prairie Fire. A Great Plains History (University Press of Kansas, 2011), p. 13.

[ii] For a distilled, popular summary, see Jim Ansley and Charles Hart, “Drivers of Vegetation Change on Texas Rangelands,” AgriLife Extension L-5534 (Feb, 2012).

[iii] The literature on brush is as extensive as its topic and has been the subject of numerous conferences.  For the particular areas I visited, I found the following publications useful as supplements to field tours by hosts: W. R. Teague,et al.,  “Integrated grazing and prescribed fire restoration strategies in a mesquite savanna: I. Vegetation responses.  Rangeland Ecology and Management 63 (2010): 275-285 , and R.J. Ansley et al, “Integrated grazing and prescribed fire restoration strategies in a mesquite savanna: II. Fire behavior and mesquite landscape cover responses,” Rangeland Ecology and Management 63(3) (2010): 286-297; R. James Ansley and G. Allen Rasmussen, “Managing Native Invasive Juniper Species Using Fire,” Weed Technology 19 (2005): 517-522; Robert K. Lyons et al, “Juniper Biology and Management in Texas,” AgriLife Extension B-6074 (Texas A&M AgriLife Communications, 2009).

[iv] Quote from interview with Jim Ansley, March 11, 2012.

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