Dead Arizona trees mystify experts

The mysterious deaths of hundreds of trees along Arizona's Santa Cruz River has prompted an investigation by environmentalists and scientists.

The experts want to determine if drought, disease, insects or some other factor is killing the trees, the Arizona Daily Star reported Thursday.

The dead trees, which might number in the thousands, are barren or covered only partially with leaves, the newspaper said. The mystery is compounded by the fact that stands of dead trees alternate with live stands.

"It's not one or two types of trees that are dying, it's every type that occurs in a riparian habitat," John Hays, flood plain coordinator for Santa Cruz County, told the Daily Star. "There's cottonwood, willow, hackberry, elderberry and mesquite. I've even seen a few salt cedars that are distressed."

"It's drought," said Jack Kelly, a commercial horticulture agent with the Pima County Cooperative Extension Service. "It's typically dieback -- the crown or top of the trees thins out."

But Ben Lomeli, a professional hydrologist, told the newspaper it's important not to jump to conclusions or dismiss any possibilities.

"It is a call for help. It's a strange case," he said.

Copyright 2005 by United Press International

Related stories:

New Orleans regroups after dodging Gustav bullet
Emergency workers hustled on Tuesday to revive a hurricane-battered New Orleans area nearly devoid of power and people, as evacuees waiting in far-away shelters clamored to return home.
Border Patrol also guards against foreign bugs
(AP) -- Alishia Beckham is on the front lines defending the United States from foreign invaders - armed with weapons that include a hand mirror and a flashlight.
Death toll climbs as Gustav barrels through Caribbean
Tropical Storm Gustav battered Jamaica on Friday, dumping rain and ripping roofs off homes and threatened to grow into a hurricane after leaving 59 people dead in Haiti and the Dominican Republic.
Novel fungus helps beetles to digest hard wood
A little known fungus tucked away in the gut of Asian longhorned beetles helps the insect munch through the hardest of woods according to a team of entomologists and biochemists. Researchers say the discovery could lead to innovative methods of controlling the invasive pest, and potentially offer more efficient ways of breaking down plant biomass for generating biofuels.
'Fay' expected to become hurricane over Cuba
Tropical storm Fay dumped heavy rains on the Dominican Republic and Haiti on Saturday, leaving two people dead and four missing, as US weather experts forecast the system will strengthen to hurricane force as it approaches Cuba.
Old growth giants limited by water-pulling ability
The Douglas-fir, state tree of Oregon, towering king of old-growth forests and one of the tallest tree species on Earth, finally stops growing taller because it just can't pull water any higher, a new study concludes.
Landscape study may offer solutions for fire managers
A fire is currently burning through a study area where projections were made about fire behavior about 2 years ago. Managers used data and analysis from the Gotchen Late-Successional Reserve (LSR) study in the planning, analysis, and implementation of treatments near where the Cold Springs fire is now active.
Exotic Chameleon Spends Most of its Life as an Egg
(PhysOrg.com) -- Scientists have discovered a chameleon species that spends a good two-thirds of its life inside an egg: Furcifer labordi lives about 8-9 months as an embryo, and has a post-hatching lifespan of just 4-5 months. As far as the scientists know, this strange life history is unique among all land vertebrates, and may help researchers better understand how certain ecological and hormonal factors influence life history evolution.

News discussion:

allopolyploidy and dead trees in Arizona in Space & Earth science news