Featured Research

from universities, journals, and other organizations

Rhododendron Expansion May Increase The Chance Of Landslides On Southern Appalachian Slopes

Date:
September 24, 2009
Source:
Southern Research Station - USDA Forest Service
Summary:
Research suggests that the expansion of rosebay rhododendron (Rhododendron maximum) in Southern Appalachian mountain hollows may increase the likelihood of landslides during and after intense rain events.

Results from a recent study suggest that rhododendron may be a key species affecting landslide initiation in the Southern Appalachians.
Credit: Erica Chapman

Research by U.S. Forest Service Southern Research Station (SRS) scientists and partners suggests that the expansion of rosebay rhododendron (Rhododendron maximum) in Southern Appalachian mountain hollows may increase the likelihood of landslides during and after intense rain events.

Related Articles


In an article recently published online in JGR-Earth Surface, SRS researchers Chelcy Ford and Jim Vose, along with T.C. Hales and Larry Band (University of North Carolina at Chapel Hill), examine how the interaction between topography and the species of tree or shrub present affects the ability of soil to hold together.

"We found that rhododendron had the shallowest, weakest roots suggesting that the recent expansion of this species may have lowered the cohesive strength of soil in some hollows," says Vose, research ecologist and project leader of the SRS Coweeta Hydrologic Laboratory located near Otto, NC. "Since debris flows usually start in the hollows, those dominated by rhododendron could represent a heightened hazard for landslides."

Landslides present a significant danger in the steep landscapes of the Southern Appalachians. Most of the recorded high rainfall events in the area occur in the fall and have been associated with tropical storms. In 1940, 1969, and 2004, intense rain from hurricanes caused landslides that together resulted in over 190 human casualties and $140 million in damage.

In 2004, rains from Hurricanes Frances and Ivan caused a large landslide at Peeks Creek in Macon County, NC, where 15 homes were destroyed, two people injured, and five people killed. With accelerating land use change and more frequent storms predicted for the area under climate change scenarios, concern about landslides has grown.

"Roots of trees and shrubs can represent up to 100 percent of what's holding soil together and keeping mountain slopes from sliding," says Vose, "For this study, we measured the root distribution and tensile strength—roughly, the force required to pull a root to the point where it breaks apart—of 15 southern Appalachian species in relation to topography and position on slopes."

The researchers dug pits down slope from 15 individual trees on the Coweeta site. The locations of trees varied from noses—convex topographic positions—to hollows. The trees included native species of oak, eastern hemlock, birch, tulip poplar, hickory, and other species. The researchers tested one woody shrub, Rhododendron maximum, a native species which has come to dominate the forest understory in some areas of the Southern Appalachians.

"We found that root strength was similar among tree species, and root strength of trees was consistently greater than that of the native shrub rhododendron," says Vose. "Tree roots in nose positions were stronger compared to those in hollows, coincident with greater root cellulose content."

Although the study was not designed to firmly establish cause and effect, the results suggest that rhododendron may be a key species affecting landslide initiation in the southern Appalachians. "Landslide events during 2004 commonly started in rhododendron thickets, including the only landslide to occur in the Coweeta drainage basin," says Vose. "The largest landslide from 2004 at Peeks Creek also formed in a rhododendron thicket."

The full text of the article can be found online at http://www.srs.fs.usda.gov/pubs/33547


Story Source:

The above story is based on materials provided by Southern Research Station - USDA Forest Service. Note: Materials may be edited for content and length.


Cite This Page:

Southern Research Station - USDA Forest Service. "Rhododendron Expansion May Increase The Chance Of Landslides On Southern Appalachian Slopes." ScienceDaily. ScienceDaily, 24 September 2009. <www.sciencedaily.com/releases/2009/08/090831213002.htm>.
Southern Research Station - USDA Forest Service. (2009, September 24). Rhododendron Expansion May Increase The Chance Of Landslides On Southern Appalachian Slopes. ScienceDaily. Retrieved February 28, 2015 from www.sciencedaily.com/releases/2009/08/090831213002.htm
Southern Research Station - USDA Forest Service. "Rhododendron Expansion May Increase The Chance Of Landslides On Southern Appalachian Slopes." ScienceDaily. www.sciencedaily.com/releases/2009/08/090831213002.htm (accessed February 28, 2015).

Share This


More From ScienceDaily



More Plants & Animals News

Saturday, February 28, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

The Best Drinks for Your Health

The Best Drinks for Your Health

Buzz60 (Feb. 27, 2015) When it comes to health and fitness, there&apos;s lots of talk about what foods to eat, but there are a few liquids that can promote good nutrition. Krystin Goodwin (@krystingoodwin) has the healthiest drinks to boost your health! Video provided by Buzz60
Powered by NewsLook.com
Cherries, Snap Peas and More Tasty Spring Produce

Cherries, Snap Peas and More Tasty Spring Produce

Buzz60 (Feb. 27, 2015) From sweet cherries to sugar snap peas, spring is the peak season for some of the tastiest and healthiest produce. Krystin Goodwin (@Krystingoodwin) has the best seasonal fruits and veggies to spring in to good health! Video provided by Buzz60
Powered by NewsLook.com
The Best Foods to Battle Stress

The Best Foods to Battle Stress

Buzz60 (Feb. 26, 2015) If you&apos;re dealing with anxiety, there are a few foods that can help. Krystin Goodwin (@krystingoodwin) has the best foods to tame stress. Video provided by Buzz60
Powered by NewsLook.com
The Amazon Keeps Its Green Thanks To The Sahara Desert

The Amazon Keeps Its Green Thanks To The Sahara Desert

Newsy (Feb. 25, 2015) Satellite data shows the Amazon rainforest supports its lush flora with a little help from Sahara Desert dust. Video provided by Newsy
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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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