By Michelle Werts

The old adage that April showers bring May flowers may be in danger.

Red maple flower
New research estimates that by 2100, the red maple (pictured) will be budding eight to 40 days earlier than it does now. Credit: Wendy VanDyk Evans,

In a new paper published in Geophysical Research Letters, a team of researchers from Princeton University reveal how a new model they’ve developed has projected that the timing of trees’ budburst will be shifting over the next century.

What is budburst exactly? It refers to when leaves, flowers and such bud on a plant or tree at the beginning of each growing season. The Princeton study looked specifically at the spring budburst of deciduous trees and what they found is that expected warmer temperatures could cause budburst to shift as much as 40 days by 2100 for certain species and climate zones. The team also discovered that budburst shifts weren’t isolated to specific types of species, such as early vs. late-budding trees, although late-budding trees will likely shift more and narrow the window between early and late buds.

Princeton’s researchers posit that these budburst shifts could lead to an alteration in forest compositions, as earlier-budding deciduous trees may begin to grow faster than evergreens. And it could affect springtime weather. As explained in Princeton’s blog on the research, “Budburst causes an abrupt change in how quickly energy, water and pollutants are exchanged between the land and the atmosphere. Once the leaves come out, energy from the sun is increasingly used to evaporate water from the leaves rather than to heat up the surface. This can lead to changes in daily temperature ranges, surface humidity, stream flow and even nutrient loss from ecosystems.”

Who knew such a seemingly little thing like a bud and its bursting time could have such big consequences?