- ALLERGY, RESPIRATORY
- Asthmatics Who Quit Smoking May Reverse Lung Damage
- Obesity May Raise Kids' Allergy Risk
- Traffic, Dust Linked to Asthma in Kids
- ALTERNATIVE MEDICINE
- Grapefruit Compound Inhibits Hepatitis C Virus
- Licorice May Block Absorption of Organ Transplant Drug
- Imaging Sheds Light on How Acupuncture Works
- ANIMAL CARE
- Beware of Dog Bites
- Animals Respond to Acupuncture's Healing Touch
- 'Comfort Dogs' Come to Emotional Rescue
- BONES & JOINTS
- In Elderly Women, Hip Fractures Often Follow Arm Breaks
- Tai Chi May Help Ward Off Knee Pain in Seniors
- Vitamin C Protects Some Elderly Men From Bone Loss
- CANCER
- Sharing Cancer Info May Be Empowering
- Smoking Ups Risk of Second Breast Cancer
- Supplement Hampers Thyroid Cancer Treatment
- CAREGIVING
- MRSA Infections Spreading to Kids in Community
- Study Links Pesticides to Birth Defects
- Mild Flu Season Coming to a Close
- CIRCULATORY SYSTEM
- Secondhand Smoke Quickly Affects Blood Vessels
- Laughter Can Boost Heart Health
- Bad Marriages Harder on Women's Health
- COSMETIC
- Study Evaluates Laser Therapies for Hair Removal
- With Psoriasis, the Internet May Offer Hope
- Health Tip: After Liposuction
- DENTAL, ORAL
- A Sweet Way to Shield Baby's Teeth
- Gum Disease Treatment Doesn't Cut Preterm Birth Risk
- Health Tip: At Risk for Gingivitis
- DIABETES
- Strict Blood Sugar Lowering Won't Ease Diabetes Heart Risk
- Poor Blood Sugar Control After Heart Surgery Impacts Outcomes
- 'Standard' Glucose Test May Be Wrong One for Obese Children
- DIET, NUTRITION
- Holiday Eating Without the Guilt -- or the Pounds
- Eating Nuts May Help Cholesterol Levels
- Polyunsaturated Fats Really May Lower Heart Risk
- DISABILITIES
- Review Finds Marijuana May Help MS Patients
- Could Your Cell Phone Help Shield You From Alzheimer's?
- ENVIRONMENTAL HEALTH
- Flame-Retardant Chemical Linked to Conception Problems
- Accumulated Lead May Affect Older Women's Brains
- Household Chemicals May Affect Cholesterol Levels
- EYE CARE, VISION
- Kids Who Spend More Time Outdoors Have Better Vision
- Eye Problems, Hearing Loss May Be Linked
- FDA Goes After Unapproved Eye Washes, Skin Ointments
- FITNESS
- Occupational Therapy Plus Exercise Benefits Osteoarthritis
- Seniors Who Exercise Help Their Health
- Higher Fitness Levels Tied to Lower Heart, Death Risks
- GASTROINTESTINAL PROBLEMS
- New Yogurt May Ease Stomach Ulcers
- Peppermint Oil, Fiber Can Fight Irritable Bowel
- New Guidelines Issued for Management of IBS
- GENERAL HEALTH
- Bacterial Infections May Succumb to Honey
- Adults Need To Get Thier Food Facts Straight
- Winter's Bitter Cold Poses Health Dangers
- HEAD & NECK
- Zen May Thicken Brain, Thwart Pain
- Ski Helmets Encouraged for All
- Many Children Will Outgrow Headaches
- HEALTH & TECHNOLOGY
- Study Suggests Link Between Cell Phones and Brain Tumors
- Save Your Aging Brain, Try Surfing The Web
- Imaging Sheds Light on How Acupuncture Works
- HEART & CARDIOVASCULAR
- Irregular Heartbeat Tied to Alzheimer's Disease
- Coffee Is Generally Heart-Friendly
- B-Vitamins Help Protect Against Stroke, Heart Disease
- INFECTIOUS DISEASE
- Older Adults May Have Some Immunity to Swine Flu
- Swine Flu Closes Three Schools in NYC
- Chinese 'Devil Dung' Plant Could Be a Swine Flu Fighter
- KID'S HEALTH
- Working Intensely Early on May Help Autistic Kids
- Treat Kids to a Safe Halloween
- Decline of Underweight Children in U.S. Continue to Fall
- MEN'S HEALTH
- Could Chinese Herb Be a Natural Viagra?
- Whole Grains, Bran May Fight Hypertension in Men
- Low Vitamin D Levels May Boost Men's Heart Attack Risk
- MENTAL HEALTH
- The Unmedicated Mind
- Vitamin C Protects Some Elderly Men From Bone Loss
- Keeping a Healthy Holiday Balance
- PREGNANCY
- Before Conceiving, Take Folic Acid for One Full Year
- Sugary Colas Tied to Gestational Diabetes
- Music of Mozart Soothes the Preemie Baby
- SENIORS
- Friends, Not Grandkids, Key to Happy Retirement
- Tai Chi May Help Ward Off Knee Pain in Seniors
- Any Old Cane Won't Do
Old-Growth Forests Dying Off in U.S. West
By eHolistic.com Published: 01/22/2009
By Steven Reinberg
HealthDay Reporter
THURSDAY, Jan. 22 (HealthDay News) -- Trees in old-growth forests in the Western United States are dying at twice the rate they were a few decades ago, and experts suspect regional warming is to blame.
The report, led by the U.S. Geological Survey (USGS), found that the increase in tree deaths has included trees in a variety of forests, elevations and sizes. Species have included pine, fir, hemlock and other coniferous trees. In addition, the rate of new tree growth has not changed, according to the report in the Jan. 23 issue of Science.
"If current trends continue, forests will become sparser over time, and average tree ages will decrease by half," study co-author Phillip van Mantgem, a USGS research ecologist, said during a teleconference Wednesday.
In the future, forests will store less carbon than they do now, van Mantgem said. "It introduces the possibility that Western forests could become net sources of carbon dioxide, further speeding up the pace of global warming," he explained.
In addition, fewer trees could result in a loss of habitat for animals that depend on old-growth forests, van Mantgem said, and there might also be an increased risk of forest fires, with increasing drought and more fallen trees.
To determine the causes of increased tree death, the researchers considered problems in the forest themselves, such as overcrowding. "Every way we cut the data and examined it, it looks like internal dynamics are not a significant source of the increase in mortality rates," Nathan Stephenson, a USGS research ecologist and co-author of the study, said during the teleconference.
The researchers also looked at external causes, such as air pollution. However, they concluded that these were unlikely causes of the troubling trend, Stephenson said.
"What we were left with was temperature," he said. "Increasing temperature was correlated with the increase in mortality rates."
Rising temperatures in the Western United States have changed weather patterns, Stephenson said. Summers are getting longer, increasing drought conditions. "It is possible that trees are under more drought stress," he said.
Moreover, warmer temperatures favor an increase in insects and other organisms that feed on trees, he said.
"Projections for the future are for continued warming, and even an accelerated rate of warming," Stephenson said. "It's very likely that mortality rates will continue to rise."
Thomas Veblen, a professor of geography at the University of Colorado at Boulder and another co-author of the study, noted during the teleconference that the findings are consistent with other ecological changes brought on by global warming.
"These include increased wildfire activity across the Western U.S., as well as bark beetle outbreaks that are occurring at unprecedented levels across Western North America," Veblen said.
He noted that these changes in climate necessitate a reevaluation of policies on how forests are managed, including new ways of dealing with wildfires and limiting development.
One critic of the concept of global warming, Steven Milloy, publisher of JunkScience.com, does not think that tree deaths have an effect on climate change.
"If they are trying to add on to climate alarmism, their paper is way short of that," Milloy said. "To say tree death is going to contribute to global warming is extremely debatable. It's all kind of silly to me."
However, two papers in the Jan. 22 issue of Nature describe other changes occurring as the earth's temperature rises.
Seasons now arrive two days earlier than they used to, one study from scientists at the University of California, Berkeley, and Harvard University concluded. Not only have average worldwide temperatures been rising for the last 50 years, according to the report, but the hottest day of the year has shifted to almost two days earlier.
And the other study found that temperatures in Antarctica have increased about half a degree in the past 50 years. The warming of Antarctica is related to changes in atmospheric circulation and declines in sea ice in the pacific region of the southern polar ocean, the University of Washington researchers concluded.
More information
For more information on climate change, visit the U.S. Environmental Protection Agency .
SOURCES: Jan. 21, 2009, teleconference with: Phillip van Mantgem, Ph.D., U.S. Geological Survey (USGS) research ecologist, Arcata, Calif.; Nathan Stephenson, Ph.D., USGS research ecologist, Three Rivers, Calif.; and Thomas Veblen, Ph.D., professor, geography, University of Colorado at Boulder; Steven Milloy, publisher, JunkScience.com; Jan. 23, 2009, Science; Jan. 22, 2009, Nature
Last Updated: Jan. 22, 2009
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