FarmerJohn
Has No Life - Lives on TB
AUSTIN, Tex. (AP) —
There was a time when horned frogs were not confined to Texas Christian University.
The real-life version of the university’s mascot, actually a kind of lizard, roamed Texas by the thousands until imported red fire ants marauded through the state, displacing the ants that served as the lizard’s food.
Today, university researchers blame the fire ant invasion and pesticides for devastating the horned toad population.
The fate of the lizard is part of a larger story about invasive species — a rogues’ gallery of weeds, grasses, insects, fish and animals that are reshaping and in many cases destroying the natural order in Texas, and in many parts of the country.
Dealing with the collective threat from invasive, or exotic, species in Texas has become a leading priority among state wildlife officials and ecological groups because of the potential damage to agriculture, water sources, recreation, the environment and the landscape. Nationwide, the economic toll of invasive species has been estimated at about $137 billion a year.
“It’s a huge economic problem,” said Damon Waitt, a biologist at the Lady Bird Johnson Wildflower Center in Austin who is also president of the Texas Invasive Plant and Pest Council. The council was formed in June to pull together federal agencies, conservation organizations, academia and other groups for a unified fight against invasive species.
“We felt like we hadn’t organized sufficiently to address this issue,” Mr. Waitt said. “Texas was behind the curve.”
At Caddo Lake, a fisherman’s paradise that straddles East Texas and northwestern Louisiana, an aquatic fern native to South America, the giant salvinia, forms huge masses on the water that block sunlight, foul boat propellers and threaten habitat. The hydrilla, a South American plant brought to the United States to decorate aquariums, has caused similar problems at Joe Pool Lake and other area waterways.
Feral hogs, wild descendants of domestic farm animals, are roaming East Texas, destroying farmland and wresting food from other animals. In the desert reaches of West Texas, a menacing evergreen known as the saltcedar, so called because it oozes salt from its leaves, is altering soil salinity and drying up small streams and rivers.
And in Arlington, botanists this year discovered a parasitic weed called branched broomrape, which attaches itself to other plants and sucks them dry of water and nutrients. Native to Europe, it is believed to have migrated to North America by ship.
Staff members at the Sunset Advisory Commission, a legislative panel that monitors state agencies, cited invasive aquatic plants as a major challenge facing the Texas Parks and Wildlife Department.
“Many nonnative plants can reproduce so rapidly as to outcompete native species, reduce oxygen levels in water and render waterways impassible to boat traffic,” the staff stated in a November report.
Some spread with alarming speed. The Chinese tallow, a tree that notoriously drives out other species, has moved to 30,000 acres from 5 acres in Galveston County. In 2006, about 30 acres of giant salvinia was spotted on Caddo Lake; today, the Brazilian plant is spread across up to 8,000 acres, said Jack Canson of the Caddo Lake Institute.
“It’s a lake killer if you don’t get it under control,” Mr. Canson said.
In many cases, the invasion is decades old, often involving plants or animals that might have been brought into the country for commercial use and then ran wild, overwhelming indigenous habitats. The bilge water in cargo ships is a frequent source of aquatic plants. Hydrilla and giant salvinia often make their way from lake to lake in Texas, stuck on boat propellers or trailers.
Nutria, beaverlike rodents, were brought to the United States for the fur trade; but they have become one of the “worst of the worst” on the Union of Concerned Scientists’ list of unwanted species because of destructive burrowing that disrupts farming and contributes to flooding. In Texas, nutria have posed a danger to mosquito fish in Big Bend National Park.
Dean Williams, an assistant biology professor at Texas Christian in Fort Worth, has taken a close look at one of the most threatening invaders, the fire ant, through his research on horned toads.
Mr. Williams and Amanda Hale, another biology faculty member, have been studying the genetics of horned toads to investigate their decline and possible replenishment.
The research is financed by the Parks and Wildlife Department with money raised from the sale of specialty license plates emblazoned with an image of the horned toad. Mr. Williams said their studies indicated that the fire ant invasion was one of “the big reasons” for the decline because it decimated the harvester ant, the lizards’ chief diet, and effectively forced horned toads into exile.
The lizards now live in diminished numbers deep in the West Texas desert.
One of the biggest problems in North Texas in recent years is hydrilla.
Tom Hungerford, a biologist with the Parks and Wildlife Department in Fort Worth, said that while the problem did not seem as severe this year, hydrilla had been a persistent nuisance in Joe Pool Lake and other area waterways, forming huge mats of vegetation that can stretch to 14 feet, to the lake bottom. “It’s like a carpet, almost,” Mr. Hungerford said.
State agencies and environmental groups are fighting back and in many cases are making progress with weapons like herbicides or exotic insects brought in to attack a particular plant. A public education campaign may also be making a difference, said Tom Harvey, a spokesman for the Parks and Wildlife Department in Austin.
“You could say the exotics have been winning the war so far,” Mr. Harvey said, “but I see a backlash where people are going to get education and take action and do something about it.”
http://www.nytimes.com/2008/12/07/s...p=1&adxnnlx=1228675883-DfE5ky1cxJIKn2ilST2Qng
There was a time when horned frogs were not confined to Texas Christian University.
The real-life version of the university’s mascot, actually a kind of lizard, roamed Texas by the thousands until imported red fire ants marauded through the state, displacing the ants that served as the lizard’s food.
Today, university researchers blame the fire ant invasion and pesticides for devastating the horned toad population.
The fate of the lizard is part of a larger story about invasive species — a rogues’ gallery of weeds, grasses, insects, fish and animals that are reshaping and in many cases destroying the natural order in Texas, and in many parts of the country.
Dealing with the collective threat from invasive, or exotic, species in Texas has become a leading priority among state wildlife officials and ecological groups because of the potential damage to agriculture, water sources, recreation, the environment and the landscape. Nationwide, the economic toll of invasive species has been estimated at about $137 billion a year.
“It’s a huge economic problem,” said Damon Waitt, a biologist at the Lady Bird Johnson Wildflower Center in Austin who is also president of the Texas Invasive Plant and Pest Council. The council was formed in June to pull together federal agencies, conservation organizations, academia and other groups for a unified fight against invasive species.
“We felt like we hadn’t organized sufficiently to address this issue,” Mr. Waitt said. “Texas was behind the curve.”
At Caddo Lake, a fisherman’s paradise that straddles East Texas and northwestern Louisiana, an aquatic fern native to South America, the giant salvinia, forms huge masses on the water that block sunlight, foul boat propellers and threaten habitat. The hydrilla, a South American plant brought to the United States to decorate aquariums, has caused similar problems at Joe Pool Lake and other area waterways.
Feral hogs, wild descendants of domestic farm animals, are roaming East Texas, destroying farmland and wresting food from other animals. In the desert reaches of West Texas, a menacing evergreen known as the saltcedar, so called because it oozes salt from its leaves, is altering soil salinity and drying up small streams and rivers.
And in Arlington, botanists this year discovered a parasitic weed called branched broomrape, which attaches itself to other plants and sucks them dry of water and nutrients. Native to Europe, it is believed to have migrated to North America by ship.
Staff members at the Sunset Advisory Commission, a legislative panel that monitors state agencies, cited invasive aquatic plants as a major challenge facing the Texas Parks and Wildlife Department.
“Many nonnative plants can reproduce so rapidly as to outcompete native species, reduce oxygen levels in water and render waterways impassible to boat traffic,” the staff stated in a November report.
Some spread with alarming speed. The Chinese tallow, a tree that notoriously drives out other species, has moved to 30,000 acres from 5 acres in Galveston County. In 2006, about 30 acres of giant salvinia was spotted on Caddo Lake; today, the Brazilian plant is spread across up to 8,000 acres, said Jack Canson of the Caddo Lake Institute.
“It’s a lake killer if you don’t get it under control,” Mr. Canson said.
In many cases, the invasion is decades old, often involving plants or animals that might have been brought into the country for commercial use and then ran wild, overwhelming indigenous habitats. The bilge water in cargo ships is a frequent source of aquatic plants. Hydrilla and giant salvinia often make their way from lake to lake in Texas, stuck on boat propellers or trailers.
Nutria, beaverlike rodents, were brought to the United States for the fur trade; but they have become one of the “worst of the worst” on the Union of Concerned Scientists’ list of unwanted species because of destructive burrowing that disrupts farming and contributes to flooding. In Texas, nutria have posed a danger to mosquito fish in Big Bend National Park.
Dean Williams, an assistant biology professor at Texas Christian in Fort Worth, has taken a close look at one of the most threatening invaders, the fire ant, through his research on horned toads.
Mr. Williams and Amanda Hale, another biology faculty member, have been studying the genetics of horned toads to investigate their decline and possible replenishment.
The research is financed by the Parks and Wildlife Department with money raised from the sale of specialty license plates emblazoned with an image of the horned toad. Mr. Williams said their studies indicated that the fire ant invasion was one of “the big reasons” for the decline because it decimated the harvester ant, the lizards’ chief diet, and effectively forced horned toads into exile.
The lizards now live in diminished numbers deep in the West Texas desert.
One of the biggest problems in North Texas in recent years is hydrilla.
Tom Hungerford, a biologist with the Parks and Wildlife Department in Fort Worth, said that while the problem did not seem as severe this year, hydrilla had been a persistent nuisance in Joe Pool Lake and other area waterways, forming huge mats of vegetation that can stretch to 14 feet, to the lake bottom. “It’s like a carpet, almost,” Mr. Hungerford said.
State agencies and environmental groups are fighting back and in many cases are making progress with weapons like herbicides or exotic insects brought in to attack a particular plant. A public education campaign may also be making a difference, said Tom Harvey, a spokesman for the Parks and Wildlife Department in Austin.
“You could say the exotics have been winning the war so far,” Mr. Harvey said, “but I see a backlash where people are going to get education and take action and do something about it.”
http://www.nytimes.com/2008/12/07/s...p=1&adxnnlx=1228675883-DfE5ky1cxJIKn2ilST2Qng
