According to a study conducted by researchers at UC Santa Barbara's National Center for Ecological Analysis and Synthesis, however, what has proved to be a boon for the economy has also been shown to have devastating effects on the environment.
High densities of the hemlock woolly adelgid, an insect native to East Asia that feeds by sucking sap from hemlock trees. In North America, it poses a major threat to eastern and Carolina hemlocks.
Balsam woolly adelgids, small wingless insects that infest and kill firs, especially Balsam Fir and Fraser Fir, were introduced from Europe around 1900. They have destroyed roughly 95 percent of the Fraser firs in the Great Smoky Mountains National Park, and have had a significant impact on forests in the Pacific Northwest.
The multidisciplinary working group found that almost 70 percent of the most damaging non-native forest insects and diseases currently afflicting U.S. forests arrived via imported live plants. The group's findings appear in the current issue of the journal Frontiers in Ecology and the Environment.
The study, led by Andrew Liebhold, a Forest Service researcher with the U.S. Department of Agriculture, shows that in the last 43 years, the quantity of plant imports to the U.S. has risen by more than 500 percent, peaking at 3.15 billion plants in 2007. Nearly half of the imported live plants entering the U.S. are destined for either California or Florida.
Once introduced, some of these imported insects and disease organisms become established, and a fraction of those become major economic pests. For example, Sudden Oak Death, which is caused by the plant pathogen Phytophthora ramorum, was introduced into the Bay Area and Big Sur regions of California via nursery plants. The disease has now spread through 14 counties in California, as well as southern Oregon, where it has caused large-scale die-off of tanoaks, live oaks, and black oaks.
The authors studied 82 high-impact invasive insects and diseases in detail. Of these, 95 percent of sap-feeding insects and 89 percent of foliage-feeding insects probably arrived on live plants. In contrast, roughly 85 percent of wood- and phloem-boring insects likely entered the country on wood packaging materials, logs, lumber, or other wood sources.
"The demand for live plants from outside the United States is not likely to diminish," said Liebhold. "As global trade expands, our knowledge of pest pathways must be improved to ensure trade is accomplished with minimal environmental degradation."
According to Liebhold, the working group's current research provides specific information that is critical to the development of policies to reduce the risk of pest species associated with the trade in live plants. Current policies are based on outdated assumptions about the size and number of shipments, and do not address the very large number of plants now grown abroad for direct resale in the U.S., he said.
The authors describe several possible means to increase bio-security, including intensified efforts at plant inspection stations; precautionary measures that restrict plants from entering the U.S. until they have been assessed as posing very little risk; expanding the post-entry quarantine currently applied mainly to some crop plants to include ornamental plants; developing better advance knowledge about pest insects and pathogens; and developing integrated systems approaches that depend on expanded partnerships between researchers and industry.
Andrea Estrada | EurekAlert!
Scientists on the road to discovering impact of urban road dust
18.01.2018 | University of Alberta
Gran Chaco: Biodiversity at High Risk
17.01.2018 | Humboldt-Universität zu Berlin
On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.
We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
19.01.2018 | Materials Sciences
19.01.2018 | Health and Medicine
19.01.2018 | Physics and Astronomy