In a new study conducted by scientists from Boston University, Harvard University, and the University of Wisconsin, they found that flowers are blooming earlier than any point recorded in history of more than 160 years.
Researchers compared records of two iconic American naturalists, Henry David Thoreau and Aldo Leopold historical data with the recent record setting high temperatures in Massachusetts and Wisconsin during 2010 and 2012.
By using these records of Thoreau and Leopold, scientists have come to the conclusion that springtime bloomers have appeared as much as a month earlier in response to the warming climate.
“Record warm temperatures (in 2010 and 2012) have resulted in record early flowering times,” said study researcher Elizabeth Ellwood of Boston University.
Thoreau began observing bloom times in Massachusetts in 1852, and Leopold got started in Wisconsin in 1935.
“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,” added Ellwood.
“We’re seeing plants that are now flowering on average over three weeks earlier than when they were first observed – and some species are flowering as much as six weeks earlier,” said senior author Charles Davis, a Harvard Professor of Organismic and Evolutionary Biology. “Spring is arriving much earlier today than it has in the past.”
Compared to spring flowering time in Thoreau’s years, the researchers found that native Massachusetts plants such as serviceberry and nodding trillium are blooming on average 11 days earlier. The change for native Wisconsin plants stood out even more, with plants blooming as much as a month earlier than they did 67 years ago when Leopold was recording springtime blooming.
Early blooming also “has tremendous implications for the environment as a whole,” Ellwood said.
Since plants soak up and evaporate water, as well as take in carbon dioxide during photosynthesis, they can influence our planet’s water cycle and atmosphere. For instance, more evaporation may mean more cloud cover, which in turn could affect rainfall, reported National Geographic.
So if you take “one plant times a million plants, you could see how atmosphere or water cycle could be affected by plants flowering earlier,” said Ellwood.
Climate scientist at the University of Bern in Switzerland, This Rutishauser notes that many scientists just observe sping and the study would have more of an impact if they included winter.
The study was published in the journal PLoS ONE on January 16.