July 3 (UPI) -- Scientists were able to analyze the impacts of climate change on trees in Belgium by studying archival footage of the Tour of Flanders, an annual cycling race.
Researchers plotted the leaf and flower production on trees and shrubs near landmarks along the race course, as revealed by television footage recorded by Flemish broadcaster VRT between 1981 and 2016.
After comparing their observations to climate data, scientists confirmed the time of leafing and flowering has shifted over time. Warmer temperatures have triggered earlier and earlier springs.
In footage from the 1980s, few leaves or flowers can be seen during the early stages of the race. The Tour of Flanders begins in early April. Fast forward a few decades and magnolia, hawthorn, hornbeam and birch trees can be seen with leaves and flower buds.
Since 1980, Belgium's early April temperatures have increased by an average of 1.5 degrees Celsius.
"Early-leafing trees can be good news for some species as they grow faster and produce more wood," Pieter De Frenne, a professor at Ghent University, said in a news release. "However, their leaves also cast shadows. When trees flush earlier in the year, they shadow for a longer period of time, affecting other animals and plants, and even whole ecosystems."
If flowers arrive too early, some may fail to receive adequate sunlight. As a result, insect species may struggle to find sufficient amounts of nectar.
Scientists believe archival footage of cycling races and other annual events could be used more often to study phenology, the timing of annual natural phenomena like leafing and flowering.
"Our method could also be used to collect data on other aspects important for ecological or evolutionary research, such as tree health, water levels in rivers and lakes, and the spread of invasive species," De Frenne said. "Only by compiling data from the past will we be able to predict the future effects of climate change on species and ecosystems."
De Frenne and his colleagues detailed their work in a paper published this week in the journal Methods in Ecology and Evolution.