The Limited Times

Now you can see non-English news...

The point of no return for tropical forests

2020-10-12T13:18:46.062Z


40% of the Amazon can become a savanna due to climate change and deforestation Less rain, more fires, little jungle; little jungle, more fires, less rain. This is the vicious circle that threatens the stability and conservation of the Amazon. 40% of the world's largest rainforest may become savanna much earlier than previously thought due to climate change and deforestation, research published in Nature Communications revealed . The research, carried out by the Stockholm Re


Less rain, more fires, little jungle;

little jungle, more fires, less rain.

This is the vicious circle that threatens the stability and conservation of the Amazon.

40% of the world's largest rainforest may become savanna much earlier than previously thought due to climate change and deforestation, research published in

Nature Communications

revealed

.

The research, carried out by the Stockholm Resilience Center, an institute specialized in the environment, warns that there are vast areas of the Amazon biome that have rainfall levels so low that they correspond to those of a savanna-type ecosystem, with dry soils, many grasslands and fewer trees than in a tropical forest.

Arie Staal, lead author of the study, states by mail that while these changes will not happen immediately, once they start they will be very difficult to stop.

“There are reasons enough to be concerned.

If the rainforests change to a degraded state and become savannas, then the original species are lost, less carbon dioxide is stored and less precipitation occurs, ”says Staal.

Rodrigo Botero, director of the Conservation and Development Foundation, an entity that has been studying and protecting the Colombian Amazon for decades, agrees with Staal on the seriousness of the savannah process of the jungle.

"If a significant part of the Amazon is sabanized, hundreds of thousands of hectares of forests will be lost, which are helping in regional climate regulation."

"If a significant part of the Amazon is sabanized, hundreds of thousands of hectares of forests will be lost, which are helping in regional climate regulation"

Botero has been investigating deforestation in the Amazon for more than 30 years and insists that without these forests, there will be less moisture retention capacity in the soils, and the flow of rivers will lose the capacity to contain avalanches or floods in winter.

The research led by Staal was carried out with computer simulation models of rainfall and also analyzed the future behavior of tropical forests in Africa, Asia and Oceania.

The paper shows that forest areas where climate change causes dryness and decreases rainfall may soon cross a point of no return.

"These results highlight that, especially in the southern Amazon and in the Congo, fires can help trigger tipping points that are difficult to reverse," the research reads.

In contrast, in Australasia, in western Oceania, the forests will remain stable.

Staal explains that the work was based on the concept of hysteresis or path dependence, understood as a process in which the past conditions the present and the future.

"In this case the hysteresis means that there may be a large tropical forest like the Amazon, but if all its trees are removed, what will regenerate later will be a smaller forest than it was in the beginning."

"In short," insists Staal, "the history of the ecosystem is decisive for its future."

Specifically, what the researchers studied was how rainforests produce their own rainfall and how this process is being altered by climate change and deforestation.

“Trees release water from their leaves and this water can rain over and over again in forests.

There is more rain in rainforests than there would be if there were no trees, ”says Staal.

The consequence of this dependency process is that if there is little rain, the region will be drier, there will be more fires and fewer trees.

And vice versa.

The larger the rainforest, the more trees there will be that can recycle water into the atmosphere.

The final consequence of this hysteresis process is that if the savannah of the tropical forest is not acted soon, it will be imminent and irreversible.

"The elimination of the forest not only affects the forest itself, but, for example, also the rains that are needed for agriculture in other regions of the planet"

Staal says that the effects of deforestation are not only local, but can affect rainfall hundreds and sometimes thousands of kilometers away.

"Therefore, the elimination of the forest not only affects the forest itself, but, for example, also the rains that are needed for agriculture in other regions of the planet," says the scientist.

Raúl Sánchez Salguero, a forestry researcher at the Pablo de Olavide University in Seville, states that the simulation of rains carried out by the researchers would be interesting to add other factors that are accelerating changes in tropical forests.

“It is not only the water cycle that causes the jungle to turn into a savanna.

In this equation we cannot forget soil degradation, human-caused forest fires and, above all, changes in land use ”.

Sánchez warns that in the last 20 years the Amazon rainforest has degraded much more than it has degraded in a century.

"Burning for agriculture or livestock radically changes soil cycles, and alters the regeneration of species," says Sánchez.

The latest NASA data reveal that 29,307 fires were registered in the Brazilian Amazon in August this year alone, the worst figure in the last ten years.

Deforestation in this region between January and July of this year was 3,000 square kilometers, almost five times the size of the city of Madrid.

Once the rainforest has crossed the threshold and becomes a mix of wood and open savanna-like grasslands, it's unlikely it will naturally return to its former state, Staal says.

The Amazon basin has already lost 20% of its surface to deforestation in the last 6 decades and the temperature has risen by one degree.

Ingo Fetzer, co-author of the paper and researcher at the Stockholm Resilience Center, said in an interview to

The Guardian

that the study shows that rainforests on all continents are very sensitive to global climate change and can rapidly lose their ability to adapt.

"Once they are gone, it will take many decades for their recovery to return to their original state. And since rainforests are home to most of all the world's species, all of this will be lost forever," concluded Fetzer.

But, how to escape from this vicious circle that has one of the most important ecosystems for the planet's conservation in danger?

Rodrigo Botero explains that to stop and transform this trend, it is urgent to stop deforestation, change land use, and create more protected areas, safeguards and areas of sustainable and responsible forest use.

"We have to start restoring areas that have been affected by deforestation, and that show signs of sabanization," says Botero. And he adds: "It is now or never. The point of no return is near, and as a society we must demand the absolute suspension of the exploitation of the Amazon. Neither mineral exports, or oil extraction, or livestock or soy and palm crops will be able to compensate for a planetary imbalance like the one that would be generated if 40% of the Amazon is sabanized. "

You can follow

MATERIA

on

Facebook

,

Twitter

,

Instagram

or subscribe here to our

newsletter

.

Source: elparis

All news articles on 2020-10-12

You may like

Life/Entertain 2024-02-12T12:04:50.088Z
News/Politics 2024-02-16T15:42:17.814Z
Tech/Game 2024-03-29T11:35:08.828Z
News/Politics 2024-02-15T16:09:30.008Z

Trends 24h

Latest

© Communities 2019 - Privacy

The information on this site is from external sources that are not under our control.
The inclusion of any links does not necessarily imply a recommendation or endorse the views expressed within them.