Early spring not so sweet for sugar maples

פורסם: 7 במאי 2012, 6:40 על ידי: Sustainability Org   [ עודכן 7 במאי 2012, 6:40 ]

04/12/2012 //  , Science and Solutions Director

© 2009 Flickr/cotinis CC BY-NC-SA 2.0

What do bowling pins, pancakes and leaf peepers have in common? The sugar maple – a species so iconic that it’s the official tree of four U.S. states and the inspiration for the Canadian flag. Sugar maples, which are found across the eastern U.S. and Canada from northern Georgia to New Brunswick, give us timber, maple syrup and amazing fall foliage. They’re also important habitat for wildlife.

Last month was the hottest March on record and the warm spring has caused problems all over the country. Now, new research from U.S. and Canadian scientists suggests that frost in the middle of a warm spring can be damaging to sugar maples.

© Flickr/Asela Jayarathne 2011 CC by 2.0

Early 2010 (like this year!) was unusually warm across the Northeast U.S., and the sugar maple leaves emerged 10-14 days earlier than normal. But then, in early May, temperatures plunged to an average low of 28 degrees Fahrenheit. In some locations, the fragile young leaves didn’t have a chance. Nearly 3,400 square miles of forest were damaged by the late frost. And because of that damage, the trees were able to take less carbon out of the atmosphere – up to 1.3 million metric tons less.

Will warm springs and late frosts mean the end of sugar maples? No. But the scientists also found that yellow birch and American beech trees – which are slower to leaf out than sugar maples, even when temperatures are high – aren’t as sensitive to frost. Meaning that as spring comes earlier in the year because of climate change, birch and beech may replace sugar maples in some locations.