What would happen if the Amazon rainforest dried out? This decades-long experiment has some answers
Cxioiana National Forest, Brazil (AP) – a short distance from the thick Amazon umbrella, suddenly opens the forest. Fallen records rot, trees grow scattered and the temperature rises in places that hit the sun’s rays. This is what 24 years of extreme dehydration in the world’s largest rainforest.
But this correction of the deteriorating forests, about the size of the football field, is a scientific experience. It was launched by Brazilian and British scientists in 2000, escaflor – The abbreviation of the “Drought Study Forest” project in Portuguese – in simulating a future climate that can exhaust Amazon rains. It is the longest project of its kind in the world, and it has become a source of dozens of academic articles in areas ranging from meteorological to the environment and physiology.
Understanding how drought can affect the Amazon, which is the area of twice the size of India that crosses to many South American countries, has traces outside the region. The rainforest stores a huge amount of carbon dioxide, a greenhouse gas that represents the main engine for climate change. according to One studyThe Amazon stores the equivalent of two years of global carbon emissions, which mainly come from burning coal, oil and gasoline. When the trees are cut, or withered and die from dryness, they are released into the carbon atmosphere that was storing, which speeds up global warming.
Creating drought conditions and monitoring results
To imitate stress from dehydration, the project is in Kxyiana National ForestAbout 6000 transparent plastic rectangular panels across one hectare (2.5 acres), and about 50 % of rainfall from the forest floor. It was set 1 meter above the ground (3.3 feet) on the sides to 4 meters (13.1 feet) above the ground in the center. The water is converted to the gutters and directed through the engraved trenches around the perimeter of the plot.
Next to him, she left a identical plot without being controlled. In both fields, the tools were connected to trees, placed on the ground and buried to measure soil moisture, air temperature, tree growth, sap and root development, from other data. Two metal towers sit on each piece.
In each tower, NASA radars measure the amount of water in plants, helping researchers to understand the comprehensive stress of forests. The data is sent to the California Space Agency’s jet laboratory, where it is processed.
“The forest was initially resistant to drought,” said Lucy Roland, a professor of environmental science at Exeter.
This started to change about 8 years. “We have really seen a significant decrease in the vital mass, large losses and mortality in the largest trees,” said Roland.
This led to the loss of about 40 % of the weight of the vegetation and carbon stored inside it from the plot. The main results were detailed in study Posted in May in Nature Ecology & Evolution. It indicates that during the years of losing vegetation, rainforests from the carbon basin, that is, a carbon dioxide store, turned into carbon emitter, before stabilizing at the end.
There was one part of the good news: the drought, which lasted for decades of time, did not turn the rain forests to Savanna, or a big herbal plain, as expected studies based on models.
The following steps include measuring forest recovery
In November, most of the 6000 transparent plastic covers were removed, and now scientists are watching how the forests change. There is currently the end date of the project.
“The forest has already been adapted. Now we want to understand what is happening after that,” said meteorological specialist Joao de Attz, Esecaflor, a professor at the Federal University of Paragraph and co -author of nature. “The idea is to know if the forest can renew and return to the basic line when we started the project.”
During a visit in April, Athaydes directed journalists in Associated Press through the site, which had many researchers. The region was so far away that most researchers had borne a full -day boat trip from Pleim, which will host the following annual climate talks at the United Nations later this year. During the days in this field, scientists remained at the Ferrera Pina’s scientific base for the Emilia Jeeldi Museum, a few hundred meters away (meters) of conspiracies.
Four teams were at work. The soil samples collected to measure the growth of the root in the top layer were collected. Weather data collected and track soil and humidity. A third of the moisture is measured by vegetation and a sacking flow. Fourth focused on vegetarian physiology.
“We do not know a little about how drought affects soil operations,” said environment scientist Rachel Salman, a researcher at Edinburgh University and one of the authors participating in the study of nature.
Essaflor dehydration simulator draws some similarities with the past two years, when many Amazon rainforests, under the influence of nino and the effect of climate change, have their cruel dry, recorded tolls. The devastating consequences ranged between the death of dozens of dolphins in the river due to warming and water decreased to vast forest fires in old developing areas.
Roland explained that the last nino has brought severe effects on the Amazon, not only through low precipitation, but also with a high temperature in temperature and steam pressure deficit, which is a measure of the extent of air drying. On the other hand, the Esecaflor experience only focused on treating soil moisture to study the effects of long -term transformations in rain.
She said, “But in both cases, we see a loss in the ability of the forest to absorb carbon.” “Instead, the carbon is fired again in the air, along with the loss of the forest cover.”
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