Cactus Smugglers Threatening Desert Ecosystems
for National Geographic News
|April 21, 2003|
The turkey vulture is not the only opportunist circling in the roasting
sun of the Chihuahuan desert for valuable quarry. A new report reveals
cactus smugglers are threatening many of the 345 cacti species found in
the 250,000 square miles (647,500 square kilometers) of the desert. This
area sprawls across the southwest United States from Texas to Arizona,
and includes much of northern Mexico.
The report was recently released by TRAFFIC, the wildlife trade monitoring network of the World Wildlife Fund (WWF) and the World Conservation Union (IUCN).
According to the report, 200 cacti speciesincluding the living rock, eagle claw, Texas barrel, hedgehog, and prickly pear cacticould be at risk if measures aren't taken to regulate harvesting in and near protected areas.
"If we don't reduce the demand we run the risk of destabilizing populations and losing species," said report co-author Christopher S. Robbins, of Biota Consulting in Portland, Oregon. "Desert dwellers from humming birds to mountain lions rely on desert plants for food or shelterremoving the cactus can be as disruptive to the ecosystem as clearcutting a forest," he said. Robbins is an advisor to TRAFFIC North America at the World Wildlife Fund in Washington D.C.
Environmentally sensitive landscaping in arid zonesxeriscapingadvocates the use of cacti and succulents to conserve scarce water resources. Xeriscaping occurs in dry cities like Phoenix, Arizona and Las Vegas, Nevada. Shipment of ornamental cacti to consumers elsewhere also contributes to the wild cacti decline.
The Chihuahuan desert is one of the world's most biologically diverse and threatened arid regions, supporting 23 percent of the world's known 1,500 cactus species. Cacti and related succulent plants evolved exclusively in the Americas, and occupy a wide range of arid and moderately humid habitats from Canada to Patagonia.
The Chihuahuan Desert is home to more mammals than Yellowstone National Park, including bison, antelope, bats, mountain lions and prairie dogs. Africa's Namib Karoo and Australia's Great Sandy Desert closely rival the Chihuahuan desert in terms of species variety.
Birds, insects and small mammals depend on cacti and succulents as a source of food. For example, the Ocotillo plant provides essential nectar for migrating hummingbirds travelling from Mexico to North America during spring.
Despite their importance in the ecosystem, "[Cacti] have been commercially harvested from this region at least since the 1940s," said A. Michael Powell, a biologist at Sul Ross State University in Alpine, Texas. The demand for cacti has increased in recent years, along with other large desert-adapted plants such as yuccas, which have been "harvested by the thousands," he said.
The most serious threats to cacti are the habitat loss of land used for grazing and plant collection for both domestic and international trade. A growing body of cactus loversknown as catophilescreate a multi-million dollar industry, states the report. They demand cacti species that are rare or new to science. Stores and private collectors in the United States absorb the majority of harvested cacti.
Europe and Japan have recently become common destinations for smuggled plants and seeds. Top destinations include the United Kingdom, Germany, and Sweden. In 1998, Mexican authorities impounded more than 800 cactus specimens from travelers entering the United States from Mexico, according to the report.
The problem of commercial collection is different in the United States and Mexican parts of the desert, said Robbins. "Mexico is home to many more rare, endemic and endangered species than the United States. These face a greater threat from over-zealous collectors from Europe and Asia who have been known to remove dozens, even hundreds, of specimens at a time," he said.
Harvesting can severely deplete wild populations that are already hampered by restricted ranges, harsh environments and low levels of seed production.
Trade in the United States may involve fewer cacti species than in Mexico, but a much greater mass of vegetation is destined for the Southwestern states' bustling Xeriscaping market.
Xeriscaping is the practice of landscaping with native plants in dry environments to conserve scant water resources.
However, this practice could in fact be mitigating one environmental condition at the expense of another. "City officials are encouraging homeowners and businesses to xeriscape," said Robbins. "Residents are heeding this conservation message a little too well by purchasing fully-grown plants collected from nearby deserts, in numbers that may exceed sustainable limits," he said.
The report cites evidence that nearly 100,000 succulents, with an estimated value of $3 million, were harvested from the wild cactus population in Texas between 1998 and 2001. These plants were mostly destined for xeriscaping in Arizona.
Although commercial cultivation is well established in Arizona and California, the market is now large enough to absorb specimens from other sources, said Robbins. Plants culled from the wild also increase profit margins for traders, as they don't require time-consuming and expensive greenhouse cultivation.
"The landscape trade is relatively new, and covers not just cacti, but many other succulents, such as yuccas, agaves, and ocotillos," said Jackie Poole, a botanist with the Texas Parks and Wildlife Department in Austin. "While landscaping with Chihuahuan Desert plants has not really caught on in Texas most of our plants are shipped to Arizona," she said.
However, commercial collection isn't as great a threat as it once was, said Poole. She has photographs that depict "millions" of small cacti piled up in the small town of Lajitas, Texas, waiting to be potted up and sent to supermarkets and variety stores. Now, much of the trade has been taken over by commercial nurseries growing cacti from seed.
While trade in Chihuahuan Desert cacti species is a major challenge, habitat destruction, especially around cities, is also a problem, added Poole. "And putting the species back into a sea of concrete and asphalt really doesn't solve the problem," she said.
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