Korean Flowering Data Show Dramatic Impact of Climate Change

 By Richard B. Primack

“I think that we may detect that some sort of preparation and faint expectation preceded every discovery we have made.”Henry David Thoreau in his Journal.

Since 1921, the Korean Meteorological Agency has been recording the flowering times of trees and shrubs in experimental gardens located at 74 weather stations across the country. This century-long record of plant activity, unequalled in all of Asia, has provided important fuel for climate change research. 

Figure 1: Sites of weather stations in South Korea.

Figure 2: Researchers at the Seoul weather station posing in front of flowering forsythia shrubs. Co-author Sangdon Lee is in the middle.

In a recently published article, we report that plants at these weather stations, including cherry trees and forsythia, are responding to record high temperatures with unprecedented earlier flowering times. There is no evidence that this advance toward ever earlier springs is stopping, as record high temperatures continue. In addition, these changes were surprisingly consistent and predictable given the magnitude and pace of change. 

Figure 3: For seven woody species, plants flower earlier in the spring in a consistent manner with warming spring temperatures. 

Why do these results matter? They show that the timing of spring is earlier now than at any point in the past 100 years. This will impact a range of natural processes and segments of society and the economy, such as agriculture and tourism, that depend on the timing of spring. It’s important to note that the changes in timing might be predictable, at least in the short term, providing an opportunity for people to anticipate and prepare for them.

Figure 4: Co-authors Sangdon Lee and Richard Primack discussing the project under a flowering cherry tree at one of the weather stations. 

As the planet continues to warm, the Korean data and this study can play a crucial role in identifying limits to nature’s response to climate change which can help guide us in minimizing the harmful impacts.

Figure 5: Planting of woody plants for monitoring at one of the weather stations.

The research team published this work in New Phytologist:   

Consistent, linear phenological shifts across a century of observations in South Korea by authors William Pearse, Michael Stemkovski, Benjamin Lee, Richard Primack, and Sangdon Lee.

Here is a link to the article: LINK