Spring's Arriving Earlier in Europe

According to trees and flowers throughout Europe, spring has jumped ahead by one week in just three decades.

Bud bursting, flowering and leaf unfolding in wild plants and agricultural crops are getting an earlier start in response to climbing temperatures.

A massive investigation of over 100,000 records involving 542 plant species in 21 European countries finds that 78 percent of the records demonstrate plants reacted to rising mean temperatures between 1971 and 2000. The study includes nearly the entire continent, from Ireland and Russia to Spain and Greece.

Seasonal milestones for vegetation in spring and summer have moved forward up to 4.6 days for every 1 °C increase in mean temperature. The advancing of leafing, flowering and fruiting averaged 2.5 days per decade.

In spring, plants growing in warmer climes have shown the strongest response to climate change. The one exception is when black locust trees burst into flower.

The autumn pattern is less consistent and pronounced than that for spring and summer. The date when leaves start turning color has advanced and delayed in a nearly equal number of cases. Fall colors have begun appearing as much as 2.4 days later with every 1 °C rise in mean temperature, but have averaged a one-day delay per degree Celsius.

The plants are responding to local temperatures in the month of and two months before an event. Timings of leafing, flowering and fruiting correspond most strongly with mean temperature of the previous month.