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Green Glossary: Old Growth Forests

Mickey Z.

By Mickey Z.
Mon Jan 12, 2009 15:39

old growth forest photo

George Diebold/Getty

An old-growth forest is "a forest stand usually at least 180-220 years old with moderate to high canopy closure; a multilayered, multispecies canopy dominated by large overstory trees; high incidence of large trees, some with broken tops and other indications of old and decaying wood (decadence); numerous large snags; and heavy accumulations of wood, including large logs on the ground."

"Rare is the forest untouched by man," writes David Biello in Scientific American. "Whether logging or clearing land for agriculture, the bulk of the world's forests have fallen to crops, cattle or younger trees. According to some estimates, less than 10 percent of forests worldwide can be considered old growth, or undisturbed for more than a century. And that is not just a tragedy for the plants and animals that require mature forests—it is also a tragedy for the world's climate."

This is because old-growth forests are usually "carbon sinks," meaning "they continue to absorb carbon dioxide from the atmosphere and mitigate climate change for centuries." Unfortunately, "we are destroying the world's precious ancient forests at an unprecedented rate. An area of natural forest the size of a soccer pitch is cut down every two seconds."

Check out the top ten ancient forests in the US.

Related Posts:

Amazing Really Old Trees

Green Glossary: Tree Sitting

 
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