It seems like an odd moment to be writing about spring and summer wildflowers, what with Old Man Winter hovering on the horizon. But scientists from Harvard and Boston Universities have unsettling news about the impact of climate change on plant life in the New England woods. The researchers have drawn on Henry David Thoreau's detailed records from 150 years ago on the flora around his beloved Walden Pond in Concord, Massachusetts. And they report that some species now flower as much as three weeks earlier than in Thoreau's day because of a 4.3 degree Fahrenheit increase in the mean annual temperature in the Concord area. The bad news is that whole groups of plants have had difficulty adapting to warmer times. Some 27 percent of the species that Thoreau recorded in the mid-19th century are now locally extinct while another 36 percent are so scarce that extinction may be imminent.
Trilliums like the wake robin are vanishing from Walden (By Les Line)
The winners? Mostly weedy plants like mustards and knotweeds and a host of non-native species. The losers? In the scientists' words, "Some of the most charismatic wildflower species in New England." They include anemonies and buttercups, lilies and trilliums, violets, saxifrages, orchids, mints, Indian pipe, bluets, roses, dogwoods, rhododenrons, Indian paintbrush, asters and goldenrods. One explanation for their decline, according to Charles Davis, a plant evolutionary biologist at Harvard, is that pollinating birds and insects have adapted to global warming and now arrive in the Concord woods well before those wildflowers blossom. "Climate change is throwing off the synchronicity of nature," Davis told the Boston Globe. If Thoreau were alive today, he said, he would write a book called Walden Lost.