Preserving the Hemlock

March 4, 2008

As part of an ongoing effort to preserve the imperiled eastern hemlock tree species, researchers from North Carolina State University have successfully located the most genetically diverse populations of the species in the southern portion of its range. They hope that by collecting the seeds from these trees the species–which is suffering both from insect infestation and prolonged drought conditions–can be saved from extinction.

Dr. Kevin Potter, research assistant professor in the Department of Forestry and Environmental Resources at NC State, and colleagues from Camcore, the largest international tree conservation partnership in the world, surveyed 20 separate populations of eastern hemlock in the southeastern United States to determine which ones contained the most genetic diversity. Their findings appear in the March edition of the journal New Forests.

Eastern hemlock (Tsuga canadensis) is an aesthetically and ecologically important species of tree found from eastern Canada to the Great Lakes states and south along the entire Appalachian mountain range. Since the hemlock tends to grow alongside streams, it plays an important role in regulating water temperature, and its loss could affect the many species of fish and insect life that inhabit mountain streams.

The tree is threatened by the prolific spread of an exotic insect known as the hemlock wooly adelgid (Adelges tsugae), which kills the trees in as few as four years. In the past decade, the hemlock wooly adelgid has infested more than 50 percent of the eastern portion of the hemlock's range, and the number is expected to grow because the adelgid, an introduced species from Asia, has no natural predators in North America.

Some researchers believe the best hope for the tree's salvation lies in "ex situ," or "off-site," preservation efforts, like those spearheaded by Camcore. Ex situ preservation involves collecting seeds from a species and planting them in preservation areas in other countries, with the hope that the species can one day be reintroduced.

Potter and his colleagues studied 20 populations of eastern hemlock scattered throughout the Southeast, an area believed to have served as a population refuge for the tree during the last ice age. They discovered the greatest genetic variation in isolated populations located on the eastern side of the Appalachian range, with a trend of decreased genetic diversity moving west into the Appalachians and to the opposite side of the mountain chain. The results will guide Camcore's collection efforts.

"You need as much genetic diversity as possible in your sample," says Potter, who conducted the research while a post-doctoral fellow with Camcore. "When a species goes through this sort of a 'genetic bottleneck' event, where its numbers really decline, you may find that the survivors may express traits that are beneficial in terms of surviving insect infestation, but that they've lost traits that help them survive other events, like drought. For preservation to be successful, you need trees with the largest possible variety of beneficial traits."

Source: NC State University, by Tracey Peake


Rank 5 /5 (5 votes)
Tags

Relevant PhysicsForums posts
  • Do some geologists actually act a lot like Randy Marsh?
    createdFeb 11, 2012
  • Discrepancy between oxygen and carbon-dioxide levels
    createdFeb 09, 2012
  • where gems are found in the world
    createdFeb 09, 2012
  • Wind Waves in Reservoir ~ Wind run-up and Wind set-up
    createdFeb 08, 2012
  • Balance of oxygen in the atmosphere
    createdFeb 01, 2012
  • The case for a methanol-based economy
    createdJan 30, 2012
  • More from Physics Forums - Earth

More news stories

Latin America mining boom clashes with conservation

Latin America is experiencing a mining boom as prices rise fuelled by a hike in global demand, but the region is also being hit by a wave of violent protests, strikes and rallies by environmentalists.

Space & Earth / Environment

created 10 hours ago | popularity 5 / 5 (1) | comments 1

Salvage workers begin pumping fuel from Italian shipwreck

Salvage workers Sunday began pumping fuel from the shipwrecked Italian cruise liner Costa Concordia, a day ahead of schedule, officials said.

Space & Earth / Environment

created 2 hours ago | popularity not rated yet | comments 0

Political leaders play key role in how worried Americans are by climate change: study

More than extreme weather events and the work of scientists, it is national political leaders who influence how much Americans worry about the threat of climate change, new research finds.

Space & Earth / Environment

created Feb 06, 2012 | popularity 5 / 5 (6) | comments 73

NASA budget will axe Mars deal with Europe: scientists

US President Barack Obama's budget proposal to be submitted next week for 2013 will cut NASA's budget by 20 percent and eliminate a major partnership with Europe on Mars exploration, scientists said Thursday.

Space & Earth / Space Exploration

created Feb 10, 2012 | popularity 5 / 5 (3) | comments 58

Humans may have helped the decline of African rainforests 3000 years ago

(PhysOrg.com) -- Large areas of rainforests in Central Africa mysteriously disappeared over three thousand years ago, to be replaced by savannas. The prevailing theory has been that the cause was a change ...

Space & Earth / Environment

created Feb 10, 2012 | popularity 4.1 / 5 (14) | comments 20 | with audio podcast report


Scientists discover molecular secrets of 2,000-year-old Chinese herbal remedy

For roughly two thousand years, Chinese herbalists have treated Malaria using a root extract, commonly known as Chang Shan, from a type of hydrangea that grows in Tibet and Nepal. More recent studies suggest that halofuginone, ...

New method to examine batteries -- MRI from the inside

There is an ever-increasing need for advanced batteries for portable electronics, such as phones, cameras, and music players, but also to power electric vehicles and to facilitate the distribution and storage of energy derived ...

Google might launch Drive for cloud storage soon

(PhysOrg.com) -- Google's next big move, according to the Wall Street Journal, is a cloud storage service called Drive. Hardly first to the plate, Google is simply catching up to introducing its cloud reposi ...

Lab study raises questions over nano-particle impact

Tests involving chickens have raised questions about the impact on health from engineered nano-particles, the ultra-fine grains commonly used in drugs and processed foods, scientists said on Sunday.

A mitosis mystery solved: How chromosomes align perfectly in a dividing cell

Although the process of mitotic cell division has been studied intensely for more than 50 years, Whitehead Institute researchers have only now solved the mystery of how cells correctly align their chromosomes during symmetric ...

Starve a virus, feed a cure? Findings show how some cells protect themselves against HIV

A protein that protects some of our immune cells from the most common and virulent form of HIV works by starving the virus of the molecular building blocks that it needs to replicate, according to research published online ...