Researchers with the Technische Universitaet Muenchen (TUM, for short) now say that, as average global temperatures continue to up thanks to climate change and global warming, trees in temperature zones of the planet are bound to get sleepier.More precisely, the specialists argue that, the hotter planet Earth gets, the more time it will take for trees in said regions to wake up from their winter slumber.
In a recent paper, the researchers detail that, according to previous investigations, trees wake up earlier from their seasonal sleep and start growing again in no time whenever winters are considerably cold.
By comparison, warm winters appear to delay this spring development phase for most forest trees in temperate zones, EurekAlert details.
“Contrary to previous assumptions, the increasing length of the day in spring plays no big role in the timing of budding. An ample 'cold sleep' is what plants need in order to wake up on time in the spring,” says researcher Julia Laube.
What researchers fear is that, once warm winters become a thing of the day, shrubs and tree species that are not native to temperate zones but that have somehow ended up growing in these areas will gain the upper hand and take over large patches of land.
It goes without saying that, should this happen, natural ecosystems in said part of the planet would sooner or later find themselves turned topsy-turvy.
“The differing growth patterns will affect the entire plant and animal world. The native tree species in our forests have only a limited ability to adapt themselves to climate change,” explains Professor Annette Menzel.
“Overall, however, a chaotic picture emerges. Through warmer winters, the usual sequence of leaf development can get completely mixed up,” the researcher goes on to argue.
To study how warmer winters will affect forests in temperate zones, the researchers looked into how 36 different tree and shrub species responded to various light and temperature conditions in so-called climate chambers.
This series of experiments confirmed the hypothesis that, unlike shrubs and invasive species, native tree species in temperature zones need exposure to very low temperatures during the wintertime to be able to get the rest that they need and spring into life without delay once the weather begins to warm.