Deforestation, or the loss of forests, continues to be a problem in many parts of the world. The Amazon rainforest is the site of the most egregious case of abusive cutting in many people’s mind – is that image still accurate?

Concerns

The Amazon Basin consists in over 2 million square miles of rainforest, the world’s largest. Only a small area of high elevation alpine fields in the Andes is not forested.

All that land eventually drains in the Amazon River, and then ultimately reaches the Atlantic Ocean. The Amazon forest contains an enormous amount of biodiversity including 40,000 plant species, over 14,000 mammals, and 3,000 species of fish. This diversity supports the livelihood of millions of people, including the members of 350 indigenous groups of which many have very little contact with the modern world. Large scale destruction of the rainforest threatens biodiversity and the people that rely on it.

Trends

Today, the Amazon forest represents about 80% of what it was back in 1970. The annual rate of deforestation reached a peak in the mid-1990s and again in the mid-2000s. Since then the rate of forest loss has slowed down. The lion share of the Amazon is located in Brazil, and for that country deforestation rates have been decreasing due to tightened environmental controls put in place by the government, environmental organizations, lenders, and large commercial clients. Among the other countries that share the rainforest in the Amazon River watershed, cutting rates have increased in Peru and Bolivia.

There has been a long history of forest loss in this region as part of a practice of slash and burn agriculture. Families would clear a plot out of the jungle to grow subsistence crops, and eventually the soil would be exhausted of its nutrients, secondary forest would grow back, and the farming activities would be pursued elsewhere. A major shift occurred in the 1970’s, when large commercial outfits cleared land to provide pastures for the beef and leather markets. Since then the major cause of Amazon rainforest loss has been this conversion to cattle pasture. The expansion of agricultural crops such as soy and sugar cane is also to blame. These agricultural commodities might not be grown on freshly cleared forests, but they usually are established on pasture lands, pushing cattle barons and their livestock deeper into the rainforest with more deforestation as a result.

Ironically, the copious amounts of rain that makes the area attractive for farming might soon cease to be so abundant. A recent study estimates that when air passes over Amazonian rainforest, it will released in the next few days twice as much water as it would if it passes over a clear cut area. Given the rate of deforestation in the Amazon, it is estimated that by 2050 rainfall there will decrease by 12% during the wet season, and 21% during the dry season.

Deforestation follows classic fragmentation patterns, starting with the incursions of roads into the forest, which is then followed by loggers, then land speculators, and cattle ranchers. The Trans-Amazonian Highway and BR-163 were particularly detrimental in that regard, adding thousands of miles of road access to interior forest. From these main roads secondary roads are built to reach logging areas, leading to a classic herringbone pattern visible in satellite imagery. In addition to logging, newly accessible areas are the subject of increased activity in mining and oil/gas development, especially in the western part of the watershed.

Conservation Efforts

Brazil is leading South America governments in terms of conservation efforts in the Amazon Basin. The Amazon Region Protected Areas (ARPA) program connects the Brazilian government, several nongovernmental organizations, and some large funders united around the goal to protect 150 million acres of rainforest. As of 2014, they were well on their way to that goal with 128 million acres now converted to conservation lands.

Sources

Spracklen et al. 2012. Observations of Increased Tropical Rainfall Preceded by Air Passage Over Forests. Nature, vol. 489.

Brazil’s Ministry of the Environment. Program ARPA.

 

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