In the 1930s, soil used as ballast to weigh down cargo ships from South America to Mobile, Alabama introduced the red imported fire ant to the southern United States. Since then, the ants have been found as far north as Maryland and as far west as California, shorting out streetlights and eating through crops and native plants in the process.
Plant pests like the fire ant cost the U.S. an estimated $37.1 billion per year in agricultural and forest ecosystem losses. And since these pests primarily enter the country through international hubs like Mobile and then spread to nearby ecosystems, the early detection of exotic pests should start at the most vulnerable urban areas.
At least that is the approach Manuel Colunga-Garcia from Michigan State University and colleagues propose in the March issue of Ecological Applications. The researchers suggest that, by establishing specific risk zones and using the information to focus resources, officials can take additional measures to prevent an influx of exotic pests while gaining knowledge about invasions.
"We can learn from cases like the fire ant that the first line of defense against exotic pests is inspections at U.S. ports," says Colunga-Garcia. "But, it doesn't stop there. With the sheer volume of imports that enter the U.S. on a daily basis—only about two percent of the imports are actually inspected—new measures have to be implemented. Our risk-zone analyses, based on recent pest invasions across an urban gradient, can help prioritize surveillance efforts."
The urban gradient framework the researchers describe starts at forests and farms in areas with the densest population and spreads outward to rural areas. The researchers base their framework on two basic assumptions: 1. The threat of introduction is greatest in urban areas receiving large quantities of imported products and their associated wood packaging, like pallets and crating that are known to harbor exotic pests, and 2. Plant ecosystems located closest to these urban areas have the greatest risk of invasion.
To identify the most threatened areas, Colunga-Garcia and colleagues selected 39 invasive plant pests reported by the North American Plant Protection Organization or the Cooperative Agriculture Plant Survey as being of U.S. economic importance. They then compiled a list of all U.S. county occurrences for each selected group of pests through July 2009. They found one or more of the 39 selected pests in 504 counties in 36 out of 48 states; 357 counties harbored just one pest, and 147 counties had two or more. Additionally, the coastal states seemed to be at greatest risk for invasion with at least one pest occurring in each.
"Major coastal urban areas, for instance, should be carefully monitored since they hold a double threat of invasion: a populous area receiving large volumes of potentially infested imports," says Colunga-Garcia. "These characteristics can lead to the rapid spread of plant pests, starting in the urban end of the gradient and moving outward to rural areas as people transport infested materials for development or recreation."
Humans are a driving factor in the spread of exotic plant pests, not just from importing plants and their associated hitchhikers directly to the ports, but likely dispersing pests inadvertently into exurban areas as well, say the researchers. Exurban development and recreational activities, such as camping, have the potential to bring infested material, like firewood, directly into sensitive ecosystems. The researchers claim the key to early detection is through careful monitoring of human activity in coastal states and other vulnerable urban areas.
"A challenge for detecting invasive pests in urban and nearby ecosystems is the fragmentation of the landscape and the many ownerships involved" says Colunga-Garcia. "Public participation in monitoring efforts will perhaps be the most economic and efficient solution for the early detection of exotic pests."
The Ecological Society of America is the world's largest professional organization of ecologists, representing 10,000 scientists in the United States and around the globe. Since its founding in 1915, ESA has promoted the responsible application of ecological principles to the solution of environmental problems through ESA reports, journals, research, and expert testimony to Congress. ESA publishes four journals and convenes an annual scientific conference.
Katie Kline | EurekAlert!
Dispersal of Fish Eggs by Water Birds – Just a Myth?
19.02.2018 | Universität Basel
Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | International Institute for Applied Systems Analysis (IIASA)
In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.
In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
19.03.2018 | Event News
16.03.2018 | Event News
13.03.2018 | Event News
21.03.2018 | Physics and Astronomy
21.03.2018 | Materials Sciences
21.03.2018 | Life Sciences