A peculiar phenomenon is taking place because of climate change. Many ecosystems move north from the equator or choose higher altitudes in search for friendlier climatic conditions. However, forests in eastern U.S. shift more towards west and not towards north. The detailed analysis of the phenomenon was published in the journal Science Advances.
More trees moved westward than northward
Dr. Songlin Fei and his team of researchers from Purdue University looked at the locations of 86 species of trees for a period of 30 years. They noticed that 62 percent of the species moved 12 miles north per decade, on average. However, something interesting caught their attention.
Seventy-three percent of trees belonging to the same sample moved west at a more rapid pace than the northward movement. Angiosperms (flowering, broad-leaved trees) were more likely to move west, while gymnosperms (non-flowering trees, conifers) moved mostly north. Also, the bigger percentage of trees shifting position was observed among saplings.
Changes in rainfall influenced these shifts
During the 30-year period, researchers noticed how temperatures increased in the east of U.S. increased by 0.29 degrees Fahrenheit. Besides, the entire country suffered major changes in rainfall. The center of U.S. witnessed an increase of more than 6 inches per year, while the south-eastern region suffered massive drops.
“Our results indicate that changes in moisture availability have stronger near-term impacts on vegetation dynamics than changes in temperature.”
Such a westward movement faces difficulties. First of all, the tree shift might run into obstacles, either natural or man-made. Also, species do not react similarly to climate change. If some trees shift their position, but other species they depend on do not, this might endanger both ecosystems.
Geological proof shows that the U.S. forests have shifted their position before, too. However, the changes were more gradual and did not occur so quickly. Nowadays, global warming acquired a rapid pace which visibly affects the environment.
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