PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Loss of eastern hemlock will affect forest water use

2013-05-09
(Press-News.org) The loss of eastern hemlock from forests in the Southern Appalachian region of the United States could permanently change the area's hydrologic cycle, reports a new study by U.S. Forest Service scientists at the Coweeta Hydrologic Laboratory (Coweeta) located in Otto, North Carolina, published online in the journal Ecological Applications and available now in preprint format.

"The hemlock woolly adelgid, an exotic invasive insect, has caused widespread hemlock mortality," says Steven Brantley, a post-doctoral researcher at Coweeta and lead author of the paper. "Hemlock decline is expected to have a major impact on forest processes, including transpiration."

Transpiration describes the loss of water from plant leaves or needles. Coweeta researchers estimated changes in transpiration at the forest-level since hemlock woolly adelgid infestation by monitoring tree water use and changes in forest composition from 2004 to 2011.

The four studied stands were once dominated by eastern hemlock trees, and are located in the Coweeta watersheds. Because of its dense evergreen foliage and dominance in riparian and cove habitats, eastern hemlock plays an important role in the area's water cycle, regulating stream flow year round.

The loss of hemlock from southern Appalachian forests can be compared to the loss of American chestnut from eastern forests, which became functionally extinct after the introduction of an exotic fungus in the early 20th century. Changes in local forest hydrology from the loss of eastern hemlock will largely depend on which species replace it.

Rhododendron, a woody evergreen shrub common in southern Appalachian forests, is one of the species replacing eastern hemlock trees. Although rhododendron is evergreen, it has lower leaf area than hemlock, and thus transpiration in rhododendron-dominated forest stands is lower than in previously-healthy hemlock forests. Most of the other species replacing eastern hemlock trees are deciduous, such as sweet birch, which unlike the evergreen rhododendron and eastern hemlock, do not transpire during the winter. Sweet birch trees also have a much higher transpiration rate than eastern hemlock trees during the growing season.

"The cumulative effect of these species changes will probably mean permanent changes in seasonal transpiration patterns," says Brantley. "In the growing season, transpiration rates will likely rise, leading to lower stream flow in the summer. However, transpiration rates in the winter will be reduced, which could cause increased winter stream discharge."

Whatever species eventually replace eastern hemlock, there will be important long-term implications for riparian habitats beyond stream discharge. Without the shade provided by eastern hemlock, stream temperatures could rise, threatening aquatic animals like eastern brook trout that require cold water for survival. The loss of eastern hemlock will not only affect the animal and plant communities in riparian habitats, but ecosystem function throughout these areas.

### 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.

Full text of the article: http://www.esajournals.org/doi/abs/10.1890/12-0616.1 Headquartered in Asheville, NC, the Southern Research Station comprises more than 120 scientists and several hundred support staff who conduct natural resource research in 20 locations across 13 southern states (Virginia to Texas). The Station's mission is "…to create the science and technology needed to sustain and enhance southern forest ecosystems and the benefits they provide." Learn more about the Southern Research Station at: http://www.srs.fs.usda.gov/.


ELSE PRESS RELEASES FROM THIS DATE:

Elevated cadmium levels linked to disease

2013-05-09
People with higher levels of cadmium in their urine — evidence of chronic exposure to the heavy metal found in industrial emissions and tobacco smoke — appear to be nearly 3.5 times more likely to die of liver disease than those with lower levels, according to a study by Johns Hopkins scientists. The research findings do not show that cadmium directly causes liver disease, the scientists caution, but do suggest an association that needs more investigation. Reviewing information from a large population-based survey, the Johns Hopkins investigators say the cadmium-liver ...

New advance in biofuel production

2013-05-09
Advanced biofuels – liquid fuels synthesized from the sugars in cellulosic biomass – offer a clean, green and renewable alternative to gasoline, diesel and jet fuels. Bringing the costs of producing these advanced biofuels down to competitive levels with petrofuels, however, is a major challenge. Researchers at the U.S. Department of Energy (DOE)'s Joint BioEnergy Institute (JBEI), a bioenergy research center led by Berkeley Lab, have taken another step towards meeting this challenge with the development of a new technique for pre-treating cellulosic biomass with ionic ...

Salk researchers chart epigenomics of stem cells that mimic early human development

2013-05-09
LA JOLLA, CA – Scientists have long known that control mechanisms known collectively as "epigenetics" play a critical role in human development, but they did not know precisely how alterations in this extra layer of biochemical instructions in DNA contribute to development. Now, in the first comprehensive analysis of epigenetic changes that occur during development, a multi-institutional group of scientists, including several from the Salk Institute for Biological Studies, has discovered how modifications in key epigenetic markers influence human embryonic stem cells ...

Study finds that bacteria organize according to 'rich-get-richer' principle

2013-05-09
Bacteria on a surface wander around and often organize into highly resilient communities known as biofilms. It turns out that they organize in a rich-get-richer pattern similar to many economies, according to a new study by researchers at UCLA, Northwestern University and the University of Washington. The study, published online May 8 in the journal Nature, is the first to identify the strategy by which bacteria form the micro-colonies that become biofilms, which can cause lethal infections. The research may have significant implications for battling stubborn bacterial ...

Doctor's choice of words may influence family's decision to permit CPR in critically ill

2013-05-09
PITTSBURGH, May 9, 2013 – A physician's choice of words when talking with family members about whether or not to try cardiopulmonary resuscitation (CPR) if a critically ill patient's heart stops may influence the decision, according to a study by University of Pittsburgh researchers in the June edition of Critical Care Medicine and now available online. "It's long been known that the way a choice is framed can influence people's decisions," noted Amber E. Barnato, M.D., M.P.H., M.S., lead author of the study and associate professor of clinical and translational science ...

Laughter perception networks in brain different for mocking, joyful or ticklish laughter

2013-05-09
A laugh may signal mockery, humor, joy or simply be a response to tickling, but each kind of laughter conveys a wealth of auditory and social information. These different kinds of laughter also spark different connections within the "laughter perception network" in the human brain depending on their context, according to research published May 8 in the open access journal PLOS ONE by Dirk Wildgruber and colleagues from the University of Tuebingen, Germany. Laughter in animals is a form of social bonding based on a primordial reflex to tickling, but human laughter has ...

Brain, not eye mechanisms keep color vision constant across lifespan

2013-05-09
Cone receptors in the human eye lose their color sensitivity with age, but our subjective experience of color remains largely unchanged over the years. This ability to compensate for age-related changes in color perception rests in higher levels of the visual system, according to research published May 8 in the open access journal PLOS ONE by Sophie Wuerger from the University of Liverpool, UK. The study included 185 participants aged 18 to 75 years with normal color vision, and revealed that the appearance of color remains largely unaffected by known age-related changes ...

In ancient China, sago palms were major plant food prior to rice cultivation

2013-05-09
Before rice cultivation became prevalent, ancient populations on the southern coast of China likely relied on sago palms as staple plant foods, according to research published May 8 in the open access journal PLOS ONE by Xiaoyan Yang and colleagues from the Chinese Academy of Sciences in Beijing, China. Little is known about prehistoric diets of those who lived in southern subtropical China, as the acidic soils and humid climate of the region cause poor preservation of plant remains. Though literature and archaeological discoveries have suggested that roots and tubers ...

Astronomers discover surprising clutch of hydrogen clouds lurking among our galactic neighbors

2013-05-09
In a dark, starless patch of intergalactic space, astronomers have discovered a never-before-seen cluster of hydrogen clouds strewn between two nearby galaxies, Andromeda (M31) and Triangulum (M33). The researchers speculate that these rarefied blobs of gas -- each about as massive as a dwarf galaxy -- condensed out of a vast and as-yet undetected reservoir of hot, ionized gas, which could have accompanied an otherwise invisible band of dark matter. The astronomers detected these objects using the National Science Foundation's Green Bank Telescope (GBT) at the National ...

Immune cells that suppress genital herpes infections identified

2013-05-09
SEATTLE – Fred Hutchinson Cancer Research Center and University of Washington scientists have identified a class of immune cells that reside long-term in the genital skin and mucosa and are believed to be responsible for suppressing recurring outbreaks of genital herpes. These immune cells also play a role in suppressing symptoms of genital herpes, which is why most sufferers of the disease are asymptomatic when viral reactivations occur. The discovery of this subtype of immune cells, called CD8αα+ T cells, opens a new avenue of research to develop a vaccine ...

LAST 30 PRESS RELEASES:

Climate crisis could force wild vanilla plants and pollinating insects apart, threatening global supply

Teens report spending 21% of each driving trip looking at their phone

Study explores the ‘social norms’ of distracted driving among teens

Diver-operated microscope brings hidden coral biology into focus

Enhancing the “feel-good” factor of urban vegetation using AI and street view images

A single genetic mutation may have made humans more vulnerable to cancer than chimpanzees

Innovative nanocomposite hydrogel shows promise for cartilage regeneration in osteoarthritis treatment

2025 Guangci Laboratory Medicine Innovation and Development Conference

LabMed Discovery is included in the ICI World Journals database

LabMed Discovery is included in the China Open Access Journal (COAJ) database

Vaccination support program reduces pneumonia-related mortality by 25 percent among the elderly

Over decades, a healthy lifestyle outperforms metformin in preventing onset of Type 2 diabetes

Mental health disorders, malaria, and heart disease most affected by covid pandemic

Green transition will boost UK productivity

Billions voted in 2024, but major new report exposes cracks in global democracy

Researchers find “forever chemicals” impact the developing male brain

Quantum leap in precision sensing across technologies

Upgrading biocrude oil into sustainable aviation fuel using zeolite-supported iron-molybdenum carbide nanocatalysts

For effective science communication, ‘just the facts’ isn’t good enough

RT-EZ: A golden gate assembly toolkit for streamlined genetic engineering of rhodotorula toruloides

Stem Cell Reports announces five new early career editors

Support networks may be the missing link for college students who seek help for excessive drinking

The New England Journal of Medicine shines spotlight on forensic pathology

Scientists discover protein that helps lung cancer spread to the brain

Perceived social status tied to cardiovascular risks in women but not in men

Brain tumor growth patterns may help inform patient care management

This might be America's first campus tree inventory

Emoji use may impact relationship outcomes

Individual merit, not solidarity, prioritized by early childhood education policies

Preclinical study unlocks a mystery of rapid mouth healing

[Press-News.org] Loss of eastern hemlock will affect forest water use