ALLERGY, RESPIRATORY
Climate Change Could Sting Allergy, Asthma Sufferers
Know Your Asthma Triggers
Overweight Moms More Likely to Have Asthmatic Kids
ALTERNATIVE MEDICINE
The Zen Way to Pain Relief
Grapefruit Compound Inhibits Hepatitis C Virus
Soybean Chemicals May Reduce Effects of Menopause
ANIMAL CARE
Beware of Dog Bites
'Comfort Dogs' Come to Emotional Rescue
Safe Toys for Dogs
BONES & JOINTS
Alcohol Abuse Can Damage Bones
Gene Therapy May Ease Rheumatoid Arthritis
Heart Failure Raises Risk of Fractures
CANCER
Some Spices Cut Cancer Risk That Comes With Grilled Burgers
No Verdict Yet on Grape Seed Extract vs. Breast Cancer
Study Suggests Link Between Cell Phones and Brain Tumors
CAREGIVING
For Dialysis Patients, More Pills = Lower Quality of Life
Health Tip: Benefitting From Adult Day Care
Babies Born in High Pollen Months at Wheezing Risk
CIRCULATORY SYSTEM
Night Shift Work Hard on the Heart
Health Tip: Are You Anemic?
An Apple a Day May Help Keep Heart Disease Away
COSMETIC
With Psoriasis, the Internet May Offer Hope
Health Tip: After Liposuction
Gum Chewing May Cut Craving for Snacks
DENTAL, ORAL
A Sweet Way to Shield Baby's Teeth
Gum Disease May Reactivate AIDS Virus
Most Insured Adults Worry About Health Care Costs: Poll
DIABETES
Older Diabetics With Depression Face Higher Death Rate
Coffee, Tea Might Stave Off Diabetes
Insulin Resistance Tied to Peripheral Artery Disease
DIET, NUTRITION
'Soda Tax' Wins Health Experts' Support
Mediterranean Diet Plus Exercise Lowers Alzheimer's Risk
Meat Additives May Be Dangerous for Kidney Patients
DISABILITIES
Review Finds Marijuana May Help MS Patients
Could Your Cell Phone Help Shield You From Alzheimer's?
ENVIRONMENTAL HEALTH
Chemical in Plastics May Cause Fertility Problems
Gene Mutation May Cause Some Cases of Seasonal Affective Disorder
Seasons Arriving 2 Days Earlier, Study Says
EYE CARE, VISION
Kids Who Spend More Time Outdoors Have Better Vision
It's a Whole New Outlook for Cataract Patients
Gene-Transfer Proves Safe for Vision Problem
FITNESS
Vigorous Exercise Can Cut Breast Cancer Risk
Fliers Can Keep Blood Clots at Bay
Simple Steps Get Walkers Moving
GASTROINTESTINAL PROBLEMS
New Yogurt May Ease Stomach Ulcers
Traditional Nonsurgical GERD Treatments Not Impressive
Peppermint Oil, Fiber Can Fight Irritable Bowel
GENERAL HEALTH
Mind Exercise Might Help Stroke Patients
Afternoon Nap Might Make You Smarter
Vinegar Might Help Keep Off Pounds
HEAD & NECK
Ski Helmets Encouraged for All
Zen May Thicken Brain, Thwart Pain
Many Children Will Outgrow Headaches
HEALTH & TECHNOLOGY
Airport Full Body Scanners Pose No Health Threat: Experts
Using Light Therapy to Silence Harmful Brain Activity
E-Mailing Your Way to Healthier Habits
HEARING
Noise Hurts Men's Hearing More, Study Shows
Summer Sounds Can Lead to Hearing Loss
HEART & CARDIOVASCULAR
Research Shows Genetic Activity of Antioxidants
Omega-3, Some Omega-6 Fatty Acids Boost Cardiovascular Health
Vitamin B3 May Help Repair Brain After a Stroke
INFECTIOUS DISEASE
Older Adults May Have Some Immunity to Swine Flu
Swine Flu Closes Three Schools in NYC
Dry Weather Boosts Odds of Flu Outbreaks
INFERTILITY
Obesity May Affect Fertility in Young Womene
KID'S HEALTH
School Phys. Ed. Injuries Up 150 Percent
Breast-Feeding May Protect a Woman's Heart
Traffic Seems to Make Kids' Asthma Worse
MEN'S HEALTH
Drinking Green Tea May Slow Prostate Cancer
Exercise May Prevent Prostate Cancer: Study Shows
The Dark Side of Vegetarianism
MENTAL HEALTH
Bullying Seems to Affect Kids Years Later
Shop 'Til You Drop: You May Feel Better
Drink Away Dementia?
PAIN
Alleviating Rheumatoid Arthritis
Are We Exercising Pain Away? Not So Much.
Acupuncture, Real or Fake, Eases Back Pain
PHYSICAL THERAPY
PREGNANCY
Calcium Supplements Cut Blood Lead Levels During Pregnancy
Woman in America Are Delaying Motherhood, Study Says
Music of Mozart Soothes the Preemie Baby
SENIORS
Eating Well And Keeping Active As You Grow Old Will Help You Stay Sharp
Boost In Elderly Population Will Be Felt Worldwide
Save Your Aging Brain, Try Surfing The Web
SEXUAL HEALTH
SLEEP DISORDERS
Moderate Aerobics May Ease Insomnia Symptoms
Daylight Savings: Not a Bright Time for All
Pay Attention to Signs That Say You're Too Fatigued to Drive
WOMEN'S HEALTH
Woman in America Are Delaying Motherhood, Study Says
Rheumatoid Arthritis Rising Among U.S. Women
Sleeping Could Help Women Lose The Baby Fat
Add your Article

Old-Growth Forests Dying Off in U.S. West

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

Copyright 2009 ScoutNews, LLC. All rights reserved.

More articles at www.eholistic.com