Wiping out an entire forest can have significant effects on global climate patterns and alter vegetation on the other side of the world, according to a study led by the University of Washington and published Nov. 16 in PLOS ONE.
"When trees die in one place, it can be good or bad for plants elsewhere, because it causes changes in one place that can ricochet to shift climate in another place," said lead author Elizabeth Garcia, a UW postdoctoral researcher in atmospheric sciences.
These local effects of deforestation are well known.
But the new study shows major forest losses can alter global climate by shifting the path of large-scale atmospheric waves or altering precipitation paths.
"People have thought about how forest loss matters for an ecosystem, and maybe for local temperatures, but they haven’t thought about how that interacts with the global climate," said co-author Abigail Swann, a UW assistant professor of atmospheric sciences and of biology.
Results show that removing trees in western North America causes cooling in Siberia, which slows forest growth there.
Losing Amazon forest had a significant positive impact on the neighboring forests in eastern South America, mostly by increasing the precipitation there during the Southern Hemisphere summer.
The study shows that when it comes to forests, one plus one does not always equal two.
"The broader idea is that we must understand and include the effects of forest loss when modeling global climate and trying to predict how climate will change in the future," said Swann.
Swann’s previous research looked at how a hypothetical massive tree planting in the Northern Hemisphere to slow global warming could have the unintended effect of changing tropical rainfall.