Bloom times are adjusting to climate change.
Thoreau’s Walden Pond may hold the secrets to global warming, according to a team of climate scientists.
Using historical data collected by famous naturalists and authors Henry David Thoreau and Aldo Leopold, a team of scientists say that the effects of global warming are now clearly evident, in part, by earlier flower blooms.
The study, published in the journal PLoS ONE, is the latest example of localized effects related to climate change. According to study researcher Elizabeth Ellwood of Boston University, using 161-year-old data on flowering times from Henry David Thoreau’s notebooks allowed researchers to graph the change in flower bloom times. The meticulous phenological records of the two iconic American naturalists, when combined with current records, shows a drastic change in bloom times.
According to researchers, local plants — such as serviceberry and nodding trillium — are blooming upwards of one week earlier. Nearly a thousand miles away in Wisconsin, where Leopold lived, the changes in bloom times are even more staggering. According to researchers, wild geranium and marsh marigold were found to have bloom times in excess of one month. In 2012, the warmest spring on record for Wisconsin, plants bloomed on average nearly a month earlier than they did 67 years ago.
“We were amazed that wildflowers in Concord flowered almost a month earlier in 2012 than they did in Thoreau’s time or any other recent year, and it turns out the same phenomenon was happening in Wisconsin where Aldo Leopold was recording flowering times. Our data shows that plants keep shifting their flowering times ever earlier as the climate continues to warm,” said Ellwood.
While the study is not the first to detail the correlation between climate change and flower bloom times, it is the first to suggest that flowers found within their natural environment are adapting in ways only seen in controlled studies. The study’s results provide scientists with an additional peek into the subtleties of ecological change in response to climate change, the latest such insight that seems to support the theory.
The study comes as number of recent studies seem to further confirm the onset of global warming. A report, co-authored by scientists at NASA and NOAA, found that 2012 was among the warmest years on record.
The new study was published online in the Public Library of Science One(PLOS ONE) by a team of researchers from Boston and Harvard Universities and the University of Wisconsin-Madison.