Image of the Day: Walnut Trees Can’t Stand the Heat

A closeup shot of a ripe walnut on a tree. Credit: Wikimedia Commons

According to research from Purdue University, hotter, drier conditions and increased odds of extreme weather events associated with climate change may prove fatal for walnut trees, bringing economic consequences to areas across the nation.

Take California, for example, which sold more than 500,000 tons of walnuts in 2010 for more than $1 billion dollars. Or Indiana, which brings in $11 million per year in walnut lumber. 

The researchers explain that walnut trees are uniquely sensitive to the cold. So they have evolved to sprout their leaves later on compared to other trees. But an extreme weather event such as a late-spring frost could be fatal. As could a drought, another climate event with possible ties to global warming, as drier conditions restrict their ability to survive without irrigation.