Trees That Once Survived Fire Now Die, say scientists, reports Christopher Joyce atNPR. A nice little ground fire every few decades cleans house in the forest, burning the grass and brush, and maybe some smaller trees — the “ladder fuels” that might carry a fire up into the tree canopy. Those canopy fires are the worst kind — they kill forests. But scientists are discovering that some trees in the West that previously would survive and thrive with small fires are now losing their ability to do so. Although trees have historically adapted to heat and drought, over long periods of such climate they are weakened by it. With little water present, trees end up sucking up air bubbles, too, which then clog their tubes, preventing them from getting water. Weakened trees are then unable to survive even small fires. This fire vulnerability is being seen throughout the numerous national parks of the West. Ultimately, air temperature is driving the system: even with decent rainfall, a hot atmosphere can suck the water right out of the ground, before plants ever have a chance of getting it.
Join the swelling numbers of voters TELLING Congress they’ll vote for Clean Energy candidates here: http://signon.org/sign/we-are-the-clean-99?source=c.em.cp&r_by=487176 . This is an ongoing campaign (the next Congressional election is in 2 years!) so please, spread the word. It’s our way of telling Congress that a strong clean energy voting bloc is out there. This is how YOU can make a difference.
For more on Climate Change, check out my weekly column at the HuffingtonPost, Climate Change This Week : http://www.huffingtonpost.com/author/index.php?author=mary-ellen-harte
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