Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Increase in Hemlock Forest Offsetting the Effect of Invasive Hemlock Woolly Adelgid -- at Least for Now

23.01.2014
Despite the accumulating destruction of a non-native invasive insect called the hemlock woolly adelgid, hemlock forests in the eastern United States appear to have held their own for now, according to new research by the U.S. Forest Service.

The key word is “appear,” said Talbot Trotter, the study’s lead author and a research ecologist with the U.S. Forest Service’s Northern Research Station.

In many regions, particularly in the southern Appalachians, the loss of hemlock to hemlock woolly adgid has been devastating. However, when Forest Service scientists used regional Forest Inventory & Analysis (FIA) data to get a big picture view of the status of hemlock in the eastern U.S., the results surprised them. “In analyzing FIA data from the 1950s through 2007, we expected to see a more pronounced impact on hemlock stands,” according to Trotter.

The data suggests that increasing tree density associated with the past century of reforestation and succession in the eastern U.S. may have offset the negative impacts of the adelgid at the regional scale.

The study, “Changes in the regional abundance of hemlock associated with the invasion of hemlock woolly adelgid,” was recently published in the journal Biological Invasions and is available at: http://www.nrs.fs.fed.us/pubs/45316

A native of Japan, the hemlock woolly adelgid was first detected in Virginia in the 1950s and for decades remained a primarily urban pest. That had changed by 1980, when the effects of infestation began to be evident in forestland within the tree’s native range. Hemlock’s native range forms a triangle from northern Georgia and South Carolina through the Appalachian Mountains into Pennsylvania, Canada and Minnesota.

Hemlock trees in the United States do not have natural defenses against hemlock woolly adelgid, which coupled with a lack of natural predators has resulted in high levels of tree mortality in the 18 states where it is known to have spread, particularly in southern states. Trotter believes that this study, which is based on forest data through 2007, may have caught hemlock at a tipping point in the balance between losses from hemlock woolly adelgid and increases due to forest regrowth.

“Repeating this analysis as new FIA data becomes available may show if we are beyond a tipping point and are now losing hemlock,” Trotter said.

Even if there were continued increases in hemlock abundance in northern climates, where cold temperatures slow damages from hemlock woolly adelgid, the loss of trees in the south is a loss to the species, Trotter said. “Losing trees in the South results in less genetic variation for hemlock,” he said.

“Non-native forest insects like the hemlock woolly adelgid are devastating on many levels because trees are so important to a region’s culture and economy,” said Michael T. Rains, Director of the U.S. Forest Service’s Northern Research Station and the Forest Products Lab. “Forest Service research is working hard to more aggressively control non-native insects and make our forests healthier and more resistant to these disturbances."

Co-authors on the study included Randall Morin, a research forester with the Northern Research Station, Sonya Oswalt, a forester with the Forest Service’s Southern Research Station, and research entomologist Andrew Liebhold with the Northern Research Station.

The study included data from 432 counties in 21 states: Alabama, Connecticut, Delaware, Georgia, Kentucky, Maine, Maryland, Massachusetts, Michigan, New Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, South Carolina, Tennessee, Vermont, Virginia, West Virginia, and Wisconsin.

The mission of the U.S. Forest Service is to sustain the health, diversity, and productivity of the nation’s forests and grasslands to meet the needs of present and future generations. The agency has either a direct or indirect role in stewardship of about 80 percent of our nation’s forests, amounting to 850 million acres including 100 million acres of urban forests gracing the nation’s cities, where 80 percent of Americans live. The mission of the Forest Service’s Northern Research Station is to improve people’s lives and help sustain the natural resources in the Northeast and Midwest through leading-edge science and effective information delivery.

Jane Hodgins | EurekAlert!
Further information:
http://www.fs.fed.us

More articles from Agricultural and Forestry Science:

nachricht Greater-than-additive management effects key in reducing corn yield gaps
18.03.2015 | University of Illinois College of Agricultural, Consumer and Environmental Sciences

nachricht Understanding plants' immune systems could lead to better tomatoes, roses, rice
12.03.2015 | University of Missouri-Columbia

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Experiment Provides the Best Look Yet at 'Warm Dense Matter' at Cores of Giant Planets

In an experiment at the Department of Energy's SLAC National Accelerator Laboratory, scientists precisely measured the temperature and structure of aluminum as...

Im Focus: Energy-autonomous and wireless monitoring protects marine gearboxes

The IPH presents a solution at HANNOVER MESSE 2015 to make ship traffic more reliable while decreasing the maintenance costs at the same time. In cooperation with project partners, the research institute from Hannover, Germany, has developed a sensor system which continuously monitors the condition of the marine gearbox, thus preventing breakdowns. Special feature: the monitoring system works wirelessly and energy-autonomously. The required electrical power is generated where it is needed – directly at the sensor.

As well as cars need to be certified regularly (in Germany by the TÜV – Technical Inspection Association), ships need to be inspected – if the powertrain stops...

Im Focus: 3-D satellite, GPS earthquake maps isolate impacts in real time

Method produced by UI researcher could improve reaction time to deadly, expensive quakes

When an earthquake hits, the faster first responders can get to an impacted area, the more likely infrastructure--and lives--can be saved.

Im Focus: Atlantic Ocean overturning found to slow down already today

The Atlantic overturning is one of Earth’s most important heat transport systems, pumping warm water northwards and cold water southwards. Also known as the Gulf Stream system, it is responsible for the mild climate in northwestern Europe. 

Scientists now found evidence for a slowdown of the overturning – multiple lines of observation suggest that in recent decades, the current system has been...

Im Focus: Robot inspects concrete garage floors and bridge roadways for damage

Because they are regularly subjected to heavy vehicle traffic, emissions, moisture and salt, above- and underground parking garages, as well as bridges, frequently experience large areas of corrosion. Most inspection systems to date have only been capable of inspecting smaller surface areas.

From April 13 to April 17 at the Hannover Messe (hall 2, exhibit booth C16), engineers from the Fraunhofer Institute for Nondestructive Testing IZFP will be...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

World Conference On Regenerative Medicine 2015: Registration And Abstract Submission Now Open

25.03.2015 | Event News

University presidents from all over the world meet in Hamburg

19.03.2015 | Event News

10. CeBiTec Symposium zum Big Data-Problem

17.03.2015 | Event News

 
Latest News

Surface-modified nanoparticles endow coatings with combined properties

26.03.2015 | Trade Fair News

Novel sensor system provides continuous smart monitoring of machinery and plant equipment

26.03.2015 | Trade Fair News

Common bacteria on verge of becoming antibiotic-resistant superbugs

26.03.2015 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>