Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Loss of Eastern Hemlock Affects Peak Flows after Extreme Storm Events

13.08.2014

The loss of eastern hemlock could affect water yield and storm flow from forest watersheds in the southern Appalachians, according to a new study by U.S. Forest Service scientists at the Coweeta Hydrologic Laboratory (Coweeta) located in Otto, North Carolina. The article was just published online in the journal Ecohydrology.

“Eastern hemlock trees have died throughout much of their range due to the hemlock woolly adelgid, an exotic invasive insect,” said Steven Brantley, a post-doctoral researcher at Coweeta and lead author of the paper.

“Though this insect has decimated whole stands of eastern hemlock along streams in the southern Appalachians, few studies have addressed the effects of this insect outbreak on landscape-level watershed processes such as stream flow.”

Because of its dense evergreen foliage, eastern hemlock plays an important role in the water cycle of southern Appalachian forests, regulating stream flow year round. Although eastern hemlock rarely dominates the region’s forests, the tree is considered a foundation species in the streamside areas called riparian zones.

Previous research by the Coweeta scientists led them to suspect that the loss of eastern hemlock would cause stream flow to increase over the short-term, especially in the dormant fall/winter season, then decrease over the longer term, with small effects annually. They also thought that peak flows after storms would increase, especially in the dormant season.

For this study, Coweeta researchers used a paired watershed approach—one watershed with a major hemlock component in the riparian forest area, the other reference watershed with very little—to determine the effects of hemlock mortality on stream flow and peak flow following storms.

Since hemlock woolly adelgid was first detected in 2003, all the eastern hemlock trees in both watersheds died, resulting in a loss of 26 percent of forest basal area (that area occupied by tree trunks and stems) in the riparian area of the first watershed compared to a 4 percent loss in the reference watershed riparian forest.

“Instead of finding that stream flow increased after hemlock mortality, we found no real change in any year after infestation,” said Brantley. “We did find, however, that peak stream flow after the largest storm events increased by more than 20 percent.”

“The fact that hemlock loss didn’t increase water yield in the short-term was due to the rapid growth response of co-occurring trees and shrubs in the riparian forests; and peak flows were likely higher after hemlock loss due to lower interception by the evergreen canopy in the riparian zone,” said Brantley.

“This latter finding suggests that riparian trees may play a disproportionally important role in regulating watershed processes than trees that aren’t adjacent to the riparian zone.”

“It also has implications for the more extreme rain events predicted under climate change,” he added. “Losing foundation species in forested riparian zones could amplify the effects of altered precipitation regimes.”

The study was conducted at the U.S. Forest Service Coweeta Hydrologic Laboratory, in the Nantahala Mountains of western North Carolina. Coweeta is one of the oldest continuous environmental studies in North America. Since 1934, precipitation, temperature, and stream flow have been continuously recorded at Coweeta, a U.S. Forest Service Southern Research Station facility. 

Access the full text of the article at www.treesearch.fs.fed.us/pubs/46230.

For more information, email Chelcy Miniat at cfminiat@fs.fed.us.

Science Contact
Chelcy Ford Miniat
828-524-2128 Ext. 118
crford@fs.fed.us

News Release Contact
Zoë Hoyle
828-257-4388
zhoyle@fs.fed.us

Chelcy Miniat | Eurek Alert!
Further information:
http://www.srs.fs.usda.gov/news/573

Further reports about: Insect outbreaks USDA forests hemlock trees insect precipitation regulating short-term species storms

More articles from Earth Sciences:

nachricht Global study of world's beaches shows threat to protected areas
19.07.2018 | NASA/Goddard Space Flight Center

nachricht NSF-supported researchers to present new results on hurricanes and other extreme events
19.07.2018 | National Science Foundation

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>