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Amazon Rainforest Fires / Origin, causes, consequences

October 19, 2019

The Amazon is an extensive tropical forest, the largest on the planet, which almost always burns in the middle of each year. Fires in that immense mass are almost inevitable.

But at times, wildfires become uncontrollable.

Over time, the rate of forest fires has increased, generally measured by the number of fire points and by the area covered by fires in the region, estimated thanks to satellite images.

Some things we should know:


1 . The difference between a fire and a fire.

Fire is the resulting action of three components: fuel, oxygen, and heat or activation energy.

That action can be controlled or not. It is controllable when certain prevention regulations are respected that take into account knowledge of climatology and the physical and chemical principles of fire.

Fire occurs when the fire becomes uncontrolled.

It can be accidental or intentionally caused, causing damage to people, animals, vegetation, infrastructure, objects in general.

When large areas of forest burn, it is called a forest fire, as is the case in the Amazon.

2. The difference between a primary forest and a secondary forest.

The primary forest, native forest or virgin forest is a natural forest that has not been exploited, fragmented or altered by human action.

Primary forests always undergo changes, but not caused by human intervention. Environmental changes are compensated by the forest ecosystem itself, which tends towards homeostasis.

Homeostasis is a natural balance that minimizes disturbances, thanks to an adequate interaction of the living organisms that make up and inhabit the forest, by competition (which implies the suppression of one of the organisms involved), commensalism (which implies a benefit mutual for organisms) and mutualism (interaction that benefits more than one organism).

It is a forest that maintains a high degree of resilience, to overcome alterations. In the Amazon there are extensive areas of primary forest.

The secondary forest is a forest that is no longer primary, because it was intervened by man, especially by logging and burning, with the purpose of colonizing the space and taking advantage of its resources.

It is a forest that regenerates over time, but has lost the balance of its ecosystems, and will no longer be able to fully recover its original state. In other words, their resilience capacity has been weakened. A forest that has been burned offers, according to experts, less and less resistance to new fires.

The primary forest is a natural “construction” of thousands of years, in which a complex interaction and evolution of the components of its ecosystems was established. Their destructive intervention causes an enormous loss for biodiversity on the planet, in short, for life. A loss that can never be recovered.

In the current Amazon there are primary forests, which still constitute the majority, and secondary forests, and deforested areas, without forest, dedicated to economic activity.

3. The difference between a natural fire and an arson fire.

Natural fires can occur in forests, such as when lightning strikes, not followed by heavy rain, and sets part of the forest on fire.

But this damage is compensated by mechanisms typical of the forest, such as rain and environmental humidity or by the formation of vegetation layers.

In the Amazon jungle it can happen, but this type of accident is not common, because they are humid tropical forests, with a lot of rainfall stimulated by the forest itself.

In the Amazon, most of the fires are provoked, intentional, which mainly pursue profit purposes, the expansion of the agricultural frontier, to establish cattle farms or plantations.

Another part, also important, is caused by native communities or settlers, who establish themselves in the forest, and clear areas for settlement and to develop farms or conucos for polycultures.

After several years of cultivation, less than ten, the soils are exhausted and they leave the farm, converted into purma, where a secondary forest slowly begins to establish itself.

4. The difference between canopy fire and understory fire.

Every forest is made up of different strata in their composition, characteristics and functions. In the forest profile, or vertical line, two areas stand out: the canopy and the undergrowth.

The canopy, or tree canopy, is the layer of branches and leaves formed by the crowns of neighboring trees , covering large areas. There, in these areas, more than 60% of the life present in the forest is found. In the Amazon it can reach an average height of about 30 meters.

Birds , small cats , sloths, monkeys , lizards, frogs, etc. live there.

A fire in the canopy ends all that life in the place.

In the canopy, the air temperature is drier and hotter, and the wind, when it is strong, becomes an element that promotes the fire, which becomes uncontrollable.

When a large tree, more than twenty meters high, for example, burns, when it dies, it falls and spreads the fire in a large space, by scattering combustible material, leaving a huge empty space in the forest.

Rain helps to moisten the cover and reduce the impact of the fire. In the Amazon forest there is a plant canopy of tall trees.

The understory is the area of forest that grows below the canopy, and that is closest to the ground.

It is a space where the temperature is less hot, because it is under the canopy cover.

In this zone, the fire is easier to control manually, and the conditions for its control are more bearable for the controllers.

There is little or no wind, and plant materials ignite more slowly, although the fire can continue for weeks before dying out. And even regrow at any time.

Experts give their opinion on the fires in the Amazon

One of them is Daniel Nepstad, doctor in forest ecology, from Yale University, interviewed by BBC/News/World, on 04. 09. 2019.

Nepstad points out that the most dangerous fires are those that affect the virgin forest, the primary forest, the one that has never been intervened.

Many animals live there, some endemic, which are very vulnerable and cannot escape, such as many species of insects , sloths and snakes. Of the trees, those that are most affected are those with thin bark.

When a fire breaks out in the Amazon, large trees die, crashing to the ground, dragging many other smaller trees, opening large gaps in the ground, and dispersing the fire that spreads to other trees. The virgin forest is exposed.

Nepstad says the exact magnitude of the fires is unknown. But it is known that if the dry season intensifies and lengthens, the effects on the forest can be very severe.

Many of these fires also occur in areas that have been previously set on fire, or where fires are set to burn part of the forest that has already been cut down.

Between 12,000 and 13,000 km2 of forest have been felled this year in Brazil, and will be burned in order to condition them for production and population settlement.

In this case there is a direct relationship between deforestation , slash and burn, and the advance of the agricultural frontier.

This process has been aggravated for some years, when deforestation has been high (from 2002 to 2004) and exceptional drought (2005, 2010).

That means that the disturbing intervention advances, and already about 18 to 20% of the forest has been deforested.

The human being must repopulate the forest

Nepstad believes that it is necessary to repopulate the Amazon forest in the most affected parts.

Its reforestation is very expensive, but possible. In Ethiopia, for example, 350 million trees were planted, but the magnitudes required by the Amazon are much larger. An effort so great that it cannot be fulfilled by local governments (of the Amazonian states) nor by the national governments (of the Amazonian countries ), but by concerted action within the framework of an “international status”, in a general agreement supported for all the countries of the basin.

For now, there is no other solution than to depend on the natural regeneration of the forest after decades, promote conservation economic activities with forest species and establish massive plans for forest protection, such as the one carried out by Brazil until 2012, which greatly reduced the rate annual deforestation.

But at the end of the program, the damage increased and even worsened.

There are more and more fires

Stefania Gozzey, in BBC/ News/ Mundo, pointed out on August 22, 2019 that the rate of fires had increased in the Brazilian Amazon by 84% compared to the same period in 2018.

One of the most severe periods of fires since 2013, when the fires officially began to be counted. This year, in the period between January and August, 74,155 fire points were registered.

Experts point out that, however, the Amazon forest presents, in a certain way, a natural barrier against the spread of fire. One of them is the canopy, that layer of the tallest trees that traps moisture in the lower part or undergrowth, making it difficult for the flames to catch or spread.

What is endangered when the Amazon catches fire?

Everyone knows that the Amazon basin, with a little less than 7 million km 2, is the largest region of humid tropical forests in the world, which is home to about 25% of terrestrial biodiversity, containing 15 to 20% of the planet’s fresh water.

These are figures that illustrate the enormous natural, biological, geographical, ecological, economic and political value of the basin . And also social.

The Amazon basin is home to more than thirty million people, including native indigenous people, mestizos, and white settlers.

The indigenous population, close to one million people, is grouped into some 380 indigenous communities, which speak 86 languages and 650 dialects, according to the United Nations Environment Program in 2016.

But the Amazon forest continues to be deforested and burned and, in practice, few concrete measures are taken to deal with the problem of forest fires, which are concentrated on deforestation to intervene in the forest and colonize it, to give land and solve problems of urban overpopulation, urged by political immediacy, fueled by a discourse often tinged with irresponsible populism.

The Amazon forest is, basically, a great climate regulator.

That immense forest controls the regional hydrological cycle. It is responsible for generating rain over the Amazon itself, southern Brazil and, to a large extent, the countries of the Río de la Plata basin.

The Amazon forest is a great regulator of the carbon cycle and the energy cycle. Forest fires reduce the function of the forest to absorb carbon.

And rather it releases it into the atmosphere, producing an environmental disaster that locally affects the forest, the population, the water, the soil.

Some corrective measures for the problem of Amazonian fires

Some programs have been established that have allowed certain improvements.

Amazon without Fire

One of them is the Amazon without Fire Program, applied in Bolivia, in 2012-2015, and in Ecuador, in 2014-2019.

The purpose of this program was to train for integrated fire management and alternative techniques to the use of fire in agricultural activities. With this program, 32 community control brigades made up of 1,235 members were formed, and 10,000 people were trained in comprehensive fire management.

Its execution allowed the reduction by 80% of the points of fire in the two Amazonian countries.

Comprehensive fire management

Another program was the regional strengthening of capacities for integrated fire management in the Amazon, which was applied in Brazil, Ecuador and Bolivia, which sought to reduce the incidence of forest fires in those countries by applying the Comprehensive Fire Management criteria. (MY F).

Bolivian program to prevent and control fires in the Amazon.

A third regional program is the sustainable management of the Amazonian landscape, which was applied in Bolivia, to increase and improve forest services, land use planning with forest management, the increase of restored systems and the coordination of efforts between the actions of the sectors public and private.

The problem of dry seasons

In the rainy season it is easier to control the fire, but this is not the case in the dry season.

When the air temperature increases and the relative humidity decreases, and it does not rain, and the dry season extends its duration, huge uncontrollable forest fires take place that devastate extensive areas of vegetation in a few weeks. And, of course, with all the living species that the forest houses.

When the temperature exceeds 30° C, and the relative humidity of the air is less than 30%, serious problems arise to control and manage the fire point.

However, when the environment cools down, between the hours of sunset and the first hours of the morning, the fire activity decreases and control and combat tasks become more efficient and safer.

Emissions resulting from forest fires

Fire not only leaves behind burned earth and bare soil, which is more prone to erosion.

Different kinds of emissions are reproduced that spread, by the wind, contaminating the burned region and the neighboring ones.

There are three types of emissions: carbon monoxide, aerosols and suspended particles.

Carbon monoxide is a highly toxic gas that aggravates respiratory diseases and causes suffocation.

That gas expands through the atmosphere for a month, and can travel thousands of kilometers carried by the wind.

The fires in the northwestern Amazon spread their effects throughout South America, from the Atlantic Ocean to the Pacific.

Aerosols are liquid or solid particles suspended in the atmosphere, such as dust, ash, and smoke.

The smoke is sometimes so dense that it affects people’s health, air traffic, and even impedes visibility from the air.

Sao Paulo, one of the most populous cities in Brazil, located about 2,500 km away from the main sources of forest fires in the Brazilian Amazon, went dark about two hours before sunset on some days in August 2019 because of the thick smoke.

Suspended particles, extrafine, hinder the quality of the air and bring with them serious respiratory problems for people.

The number of children hospitalized in the Brazilian states of Pará, Rondônia, Maranhao and Mato Grosso doubled in the two months from May to June 2019, compared to the same period in 2018, reaching 2,500 more hospitalizations than expected.

The same happened with children hospitalized for the effects of burns.

Deforestation: the great responsible

All studies on the causes of forest fires in the Amazon conclude that the main culprit is the deforestation of the forest.

Dr. Jos Barlow, Professor of Conservation Science, at the English University of Lancaster, in the vicinity of a beautiful national park in the North West of England, maintains that the great culprit of the devastation of the Amazon is deforestation.

The burning of the forest that follows deforestation makes it more flammable, even regenerating. It becomes increasingly vulnerable to new fires. This situation of vulnerability becomes extremely dramatic during prolonged droughts.

Climate change, Barlow points out, is causing temperatures to rise in the Amazon, making the forest more flammable, especially during the dry season.

With each passing decade, the regional temperature rises. The largest fire outbreaks begin in the southern zone. Then it passes to the central and eastern zones of the Amazon, complicating the scenario when the El Niño phenomenon arrives, as it happened in the 2015-2016 period.

Massive logging and burning, without control and indiscriminate, makes the forest more and more flammable, because deforestation reduces rainfall at the local level, and increases the edge areas of the forest, which are drier areas and with very individuals.

Behind the deforestation carried out by the landless peasants are the landowners, who use the poor peasant as the spearhead of a process of growing expansion of the agricultural frontier in large areas of the Amazon.

This post is also available in: Español (Spanish)