Texas wildfires made worse by changes on the state’s vast landscape, scientists say
Texas wildfires made worse by changes on the state’s vast landscape, scientists say
05 May 2011
published by www.bellinghamherald.com
USA — Scorched Texas is sprouting green. Almost before the embers cooled, nature began its renewal.
“There’s already grass popping up in the black,” said Greg Creacy, a regional fire and natural resources coordinator with the Texas Parks and Wildlife Department.
Yet the signs of underlying trouble also will re-emerge.
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The drought-fed fires of 2011, which have burned 2 million acres since December, were symptoms of damaging, long-term changes on the Texas landscape.
In North Texas, a shift from open grasslands to nearly unbroken expanses of extremely flammable junipers has turned what would otherwise be occasional and moderate fires into infernos of arresting power. That was the case with the recent fires near Possum Kingdom Lake.
At the same time, West Texas ranchland, with a buildup of grasses left ungrazed for conservation and then dried by drought, have become potential torches. And in East Texas, many forest tracts sold off by big timber and paper companies to hundreds of small owners are no longer managed in a way that could reduce wildfire risks.
Those conditions are making wildfires more intense and dangerous. That’s especially true in Central Texas, stretching up to the low hills west of Dallas-Fort Worth.
The increasingly suburbanized region now faces the same hazard as another state in which wildfires and human safety are closely intertwined.
“It’s ‘Little California,'” said Carlton Britton, professor of fire ecology at Texas Tech University in Lubbock.
One reason for the new strength of Texas wildfire lies in the management – or lack of it – of the land.
Outside of West Texas ranch country, where generations of owners have developed a keen sense of fire’s importance, relatively few landowners use the most effective tool against uncontrolled, destructive wildfires.
Prescribed, controlled burning restores pastures, holds back the growth of fire-prone trees and reduces undesirable fuel loads. It mimics fire’s natural role in shaping the landscape.
Without periodic low-intensity fires, trees can take over. The Ashe junipers of Central Texas – “mountain cedar” to many Texans – are natives, but natural fire and intentional burning by Indians and settlers helped to confine them to distinct locations.
Texas agencies and universities teach landowners how to use fire, and in some communities, people have formed burning cooperatives to share expertise and costs.
Still, the loss of cultural knowledge, institutional roadblocks – it’s hard for Texas landowners and fire contractors to get liability insurance for controlled burning – and decades of suppressing every small wildfire have taken a heavy toll.
The land itself is the proof.
A century and a half ago, Central Texas was a mosaic of grasses, some patches of trees and some sizable forested acreage, maintained in approximate proportions by fires every five to seven years.
A visitor today sees a wooded terrain, with dense junipers covering many hillsides and homes tucked among the trees. Fire is seen now only as the enemy in those places – understandably, since a bad fire could be a disaster for people.
The absence of moderate wildfires has dramatically boosted the risks of catastrophic ones.
Junipers contain volatile oils that can make them virtually explode when ignited. Because the trees grow together, they form a continuous layer. A spark can start a crown fire that sprints through the treetops at the speed of the wind.
Firefighters have a term for such trees: gasoline on a stick.
“No firefighter on the ground with water is going to stop that,” said Roger Wittie, professor and head of agribusiness, agronomy, horticulture and range management at Tarleton State University in Stephenville.
Only water or flame retardant dropped from aircraft can work. However, the same wind that pushes the flames frequently keeps the planes grounded.
Flames from the juniper crown fires around Possum Kingdom Lake left scorch marks almost to the top of a 150-foot-tall water tower.
One firefighter recounted to Justice Jones, a wildfire expert with the Texas Forest Service, how he watched the fire creating its own weather.
Four times, the firefighter said, he saw huge columns of fire and smoke shoot skyward with the heat, forming mushroom clouds.
The air cooled as it rose, making the columns collapse. Falling flames hit the ground and spread out “like pouring water onto a table,” Jones said.
The fires west of Dallas-Fort Worth were worsened by development patterns. Urban residents escaping to the scenic hills for the weekend want shady lots and don’t view the dense juniper growths as threats, Wittie said.
In the process, he said, they have fragmented habitats and introduced more chances to start a fire, from an outdoor grill to a vehicle left idling over a patch of grass.
The same threat exists elsewhere, especially in the affluent developments in the hills overlooking the state capital.
“West Austin is going to go up one of these days,” said Britton, “and it’s not going to be pretty.”
Along with the warnings, however, the fires also left hope for a healthier, more diverse landscape.
Creacy coordinates controlled burns on Texas Parks and Wildlife Department land in his region. Controlled – that’s the way he prefers it.
“We pick the time; we pick the temperature,” he said. “It’s a long and detailed process.”
Possum Kingdom State Park was on a list for prescribed fire to reduce juniper domination and renew the habitat, but time and money hadn’t allowed it yet.
Nature did it anyway. The fire that burned 90 percent of the park was extreme and violent, but the results will be welcomed.
“We’ll see a very positive benefit to PK,” Creacy said. The junipers are fire-intolerant, as land managers say; in lay terms, many are obliterated.
More open grasslands will return soon, Creacy said. Perhaps some little bluestem, the classic Central Texas prairie grass, will recolonize areas where the shade of the juniper thicket had kept it away.
“In two or three weeks, the area will be very green,” Creacy said.
“By the end of summer, we’ll have lots of grasses and wildflowers.”
TEXAS FIRE THREAT
Two million acres of Texas have burned since December – but the stage was set long ago.
Relatively few landowners use the most effective tool against destructive wildfires: controlled burns, which hold back the growth of fire-prone trees and reduce undesirable fuel loads.
The Ashe junipers of Central Texas are very flammable. Intentional burning by Indians and settlers helped to confine them. The trees contain volatile oils that explode when ignited.
Texas has changed greatly, and dense junipers now cover many hillsides with homes tucked among the trees.
