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A new study suggests that by 2100 this spring "budburst" — when buds turn into leaves — could be up to five weeks earlier in the Northern areas of the U.S. and would come about a week earlier in the South. These changes would have huge, unpredictable impacts on forest
(The study focused on these biologically relevant dates that indicate spring, instead of the "official" start of spring, the equinox, March 20.)
The study was published in the journal Geophysical Research Letters. They used data from the USA National Phenology Network and simulated how climate change would impact the "budburst" date of forest trees in different areas.
Spring is already coming about three days earlier than it did between 1951 and 1980, on March 17 instead of March 20. Fall could even start coming later, as well, extending the summer and the growing season, though there will also be more frequent and more intense drought and heat waves.
It's not all daises and pollen, though. An earlier spring will most likely cause widespread problems. ClimateCentral.org sums it up nicely:
If spring comes earlier, some species will adapt more easily than others, throwing that balance off by, for example, disturbing the relationship between
What they can predict is that “the North is going to become more South-like,” [study author David] Medvigy said. “It could lead to a homogenizing of ecosystems,” in which regional ecosystems that now look very different would begin to look alike. That might, in turn, alter the migratory behavior [of] many species of birds and insects — a ripple effect that could lead to further changes in ecosystems.
All of these factors will impact how much carbon dioxide forests take up during the growing season and change the makeup of these forests in unpredictable ways.