Tuesday, December 11, 2012

World's biggest, oldest trees dying at faster pace

The world's largest and oldest trees are dying at an alarmingly fast pace, researchers have found. Their study, to be published in the journal Science on Friday, warns that more research to understand and slow the loss of these trees in "urgently needed," Jim Robbins of The New York Times reports. Australian National University professor and lead author David Lindemayer said the tree deaths appear to be happening in all types of forests at all latitudes. (Reuters photo: diseased ash tree in center)

Researchers said the cause is a combination of factors, including a hotter, drier climate, logging, clear-cutting, changes in forest fire prevention and management, invasive insect attacks and diseases. These 100- to 300-year old trees sustain biodiversity "to a greater degree than many other components of the forest," making their die-offs very concerning, researchers say. "Big, old trees are not just enlarged young trees," University of Washington professor and study co-author Jerry Franklin said. "Old trees have idiosyncratic features – a different canopy, different branch systems, a lot of cavities, thicker bark and more heartwood. They provide a lot more habitat and niches."

Big trees also provide food supplies to numerous animal species, and store large amounts of carbon, recycle soil nutrients and contribute to the flow of water and climate within an ecosystem, Robbins reports. "It is a very, very disturbing trend," James Cook University professor and co-author Bill Laurance said. "We are talking about the loss of the biggest living organisms that play a key role in regulating and enriching our world." (Read more)

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