Researchers Use Thoreau’s Journals To Find Climate Change’s Impact On Wildflowers

Feb 8, 2019

As the planet warms, regional wildflowers are in danger of declining.

Researchers at several universities and the Carnegie Museum of Natural History have found climate change is causing spring wildflowers to bloom one week earlier than they did 160 years ago. Trees are producing leaves, or "leafing out," two weeks earlier than they used to.

The research team found this change by studying the journal entries of writer and naturalist Henry David Thoreau, who painstakingly tracked plant life near Walden Pond in Massachusetts in the mid-1800s. 

Mason Heberling, assistant curator of botany at the Museum, said the time between wildflowers blooming and the trees above them growing leaves is a critical period for the flowers. Most of their energy for the season is gathered from the sun in that time span.

"So, if the trees are leafing out earlier and ealier, that could have some pretty substantial consequences," Heberling said. "In the long term this could lead to the decline of many of these wildflower species that we love."

Heberling said the time between wildflowers blooming and trees producing leaves currently ranges from about three to seven weeks, depending on the species. Heberling said the team plans to continue their research to find out what happens when wildflowers bloom in increasingly shaded environments. 

Photo courtesy of Nicholas A. Tonelli on Flickr.