It is well known that forests are the lungs of the planet , they release part of the oxygen we breathe and also fix atmospheric carbon , contributing to our fight against the effects of climate change. However, this is not all, a group of ecologists from the University of Utrecht, has discovered that forests also help prevent desertification.
As published in the journal Global Change Biology , forests around the world help control rain cycles. Everything is related, the water released by a specific forest area, in the form of condensation clouds, can travel thousands of kilometers and stabilize the rain cycles of distant forests.
“It was already known that large rainforests, such as the Amazon and the Congo, maintain stable rain cycles locally because they pump evaporated water throughout the year. The question was whether this same process also occurred at a global level, ” says Maria João Santos, co-author of the study.
To test this, the researchers used climate models based on patterns known as atmospheric pressure and wind , in which they tracked the movement of water particles through the atmosphere. They also divided the world into squared cells and estimated the chances of rain in each of them.
The results were surprising, since they showed that cells that received 50% or more of rainfall from forests had a 60% more stable rainfall regime than those that received particles from non-forest or ocean areas. Therefore, forests at a global level not only affect rainfall in remote areas, but also reduce variations in the frequency of rainfall, promoting much more stable biomes.
After comparing the different forest areas, they saw that this range was not unique to the tropics. “We show that, in general, all the world’s forests have this effect,” says Santos. “Even rainfall patterns in non-forest areas, such as grasslands and savannas, depend largely on condensed water molecules in remote forests” .
The Ph.D. John C. O’Connor, from the same university and the main author of the study, argues that now the next step is to calculate exactly how far the condensation reaches each of the forests. “It is a question of global politics, since the winds do not understand borders”, says the scientist. “Forests in northwestern Canada, for example, could hypothetically provide water that helps stabilize rain cycles on the east coast of the United States.” For this reason, in the face of the coming effects of climate change, which predict numerous droughts, now more than ever policies must be implemented to further protect forest ecosystems, which are largely responsible for regulating variations in rainfall at a global level.
References:
O’Connor, J. C., Dekker, S. C., Staal, A., Tuinenburg, O. A., Rebel, K. T., & Santos, M. J. (2021). Forests buffer against variations in precipitation. Global Change Biology, 27(19), 4686–4696. https://doi.org/10.1111/gcb.15763
