<http://schema.org/alternativeHeadline>
"The production of maple syrup requires long stretches of springtime cold nights and warm days. Global warming is disrupting that pattern and could knock it out for good."^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.mnn.com/earth-matters/climate-weather/blogs/maple-syrup-global-warming-casualty>