Featured Research

from universities, journals, and other organizations

Ecologists call for screening imported plants to prevent a new wave of invasive species

Date:
January 5, 2012
Source:
University of Massachusetts at Amherst
Summary:
A recent analysis suggests that climate change predicted for the United States will boost demand for imported drought- and heat-tolerant landscaping plants from Africa and the Middle East. This greatly increases the risk that a new wave of invasives will overrun native ecosystems in the way kudzu, Oriental bittersweet and purple loosestrife have in the past, members of the international team say.

Proactive screening of invasion risk before new plants are introduced could prevent problems like oriental bittersweet, pictured here dominating a hedgerow, including large trees. Bittersweet vines were introduced as an ornamental for their attractive berries, but have expanded throughout New England, choking and shading native forest plants.
Credit: Image courtesy of University of Massachusetts at Amherst

A recent analysis led by ecologist Bethany Bradley at the University of Massachusetts Amherst suggests that climate change predicted for the United States will boost demand for imported drought- and heat-tolerant landscaping plants from Africa and the Middle East. This greatly increases the risk that a new wave of invasives will overrun native ecosystems in the way kudzu, Oriental bittersweet and purple loosestrife have in the past, members of the international team say.

The kudzu invasion of the past few decades saw whole forests overgrown in the Southeast, along with hedgerows, power lines and even houses. In wetlands across the nation, purple loosestrife is crowding out native marsh plants, and Oriental bittersweet, if left unchecked, shades and chokes out native trees, bushes and shrubs along streams, forest and field edges.

Bradley and colleagues recommend that U.S. authorities adopt proactive management practices, in particular pre-emptive screening of nursery stock before new plants are imported, to prevent such an explosion of new invasives. Their conclusions appear in an early online edition of the Feb. 1 issue of Frontiers in Ecology and the Environment.

As the UMass Amherst environmental conservationist and lead author explains, the U.S. Department of Agriculture (USDA) has proposed the Not Authorized Pending Pest Risk Analysis (NAPPRA) rule to regulate the industry. The rule would require importers to notify the USDA of proposed imports. USDA scientists would then conduct a timely risk assessment and issue a recommendation to allow or curtail the import.

"Our study identifies climate change as a risk, which combined with other factors is likely to increase demand for imported heat- and drought-tolerant plants, but this emerging threat is one that policy can effectively address," Bradley says. "The USDA has tools to reduce import risk and we advocate that now is the time put them in place. Pre-import screening has been tested in Australia for about 10 years now and it's not foolproof, but it seems to have done a good job of separating the really bad import ideas from more benign introductions."

Not all imported plants become invasive, but those that do can become a significant threat to native plants and we should not be complacent about the current situation, she says. About 60 percent of plants now considered invasive were introduced deliberately through the plant trade. The other 40 percent are human-related accidental introductions such as seeds stuck in cargo or shipping containers. Only a tiny fraction of non-native introductions are from natural causes such as blowing in with a hurricane, Bradley says.

She and colleagues point out that rising average temperatures in certain regions of the U.S. are already shifting plant hardiness zones northward and the trend is expected to continue globally. Their study suggests that with the earlier onset of spring, warmer winters, economic globalization and increased trade with emerging economies in Asia and Africa, we may face a significant new wave of invasive plant introductions.

For this analysis of the intersection of global trade and climate change, the ecologists used import values from 1989 to 2010 to identify emerging trade partners, because earlier studies had established a clear link between increased trade and the number of invasive species. They found 42 emerging trade partners poised to supply new nursery plant varieties including Thailand, Egypt, Saudi Arabia, Ecuador, Argentina and several in equatorial Africa.

The rate of introduction is steepest in the early stages of new trade relationships, the authors say. "Unfortunately, increasing the variety and availability of non-native, drought-tolerant species could also increase the probability of introducing species capable of invading dryland regions." Bradley adds, "In the desert Southwest this has already been happening with xeriscaping, which is becoming more and more popular." Xeriscaping refers to gardening with low or no need for watering.

Bradley and colleagues' work focuses on introduction, the first of three stages of invasion, because "stopping invasions before they start is the most effective way of preventing widespread ecological and economic impacts," she says. "Globalization has accelerated the rate of introduction from a few species at the first colonization of North America to now, when we probably see thousands of new species each year. All we need is another kudzu to have a big impact."

This work was supported by the National Science Foundation's National Center for Ecological Analysis and Synthesis.


Story Source:

The above story is based on materials provided by University of Massachusetts at Amherst. Note: Materials may be edited for content and length.


Journal Reference:

  1. Bethany A Bradley, Dana M Blumenthal, Regan Early, Edwin D Grosholz, Joshua J Lawler, Luke P Miller, Cascade JB Sorte, Carla M D'Antonio, Jeffrey M Diez, Jeffrey S Dukes, Ines Ibanez, Julian D Olden. Global change, global trade, and the next wave of plant invasions. Frontiers in Ecology and the Environment, 2011; 111202080547004 DOI: 10.1890/110145

Cite This Page:

University of Massachusetts at Amherst. "Ecologists call for screening imported plants to prevent a new wave of invasive species." ScienceDaily. ScienceDaily, 5 January 2012. <www.sciencedaily.com/releases/2012/01/120104153735.htm>.
University of Massachusetts at Amherst. (2012, January 5). Ecologists call for screening imported plants to prevent a new wave of invasive species. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2012/01/120104153735.htm
University of Massachusetts at Amherst. "Ecologists call for screening imported plants to prevent a new wave of invasive species." ScienceDaily. www.sciencedaily.com/releases/2012/01/120104153735.htm (accessed July 25, 2014).

Share This




More Earth & Climate News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Virginia Governor Tours Tornado Aftermath

Virginia Governor Tours Tornado Aftermath

AP (July 25, 2014) Virginia Gov. Terry McAuliffe toured the Cherrystone Family Camping and RV Resort on the Chesapeake Bay today, a day after it was hit by a tornado. The storm claimed two lives and injured dozens of others. (July 25) Video provided by AP
Powered by NewsLook.com
Europe's Highest Train Turns 80 in French Pyrenees

Europe's Highest Train Turns 80 in French Pyrenees

AFP (July 25, 2014) Europe's highest train, the little train of Artouste in the French Pyrenees, celebrates its 80th birthday. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
Goma Cheese Brings Whiff of New Hope to DRC

Goma Cheese Brings Whiff of New Hope to DRC

Reuters - Business Video Online (July 24, 2014) The eastern region of the Democratic Republic of Congo, mainly known for conflict and instability, is an unlikely place for the production of fine cheese. But a farm in the village of Masisi, in North Kivu is slowly transforming perceptions of the area. Known simply as Goma cheese, the Congolese version of Dutch gouda has gained popularity through out the region. Ciara Sutton reports. Video provided by Reuters
Powered by NewsLook.com
Bill Gates: Health, Agriculture Key to Africa's Development

Bill Gates: Health, Agriculture Key to Africa's Development

AFP (July 24, 2014) Health and agriculture development are key if African countries are to overcome poverty and grow, US software billionaire Bill Gates said Thursday, as he received an honourary degree in Ethiopia. Duration: 00:36 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins