Agriculture & Ranching | Deforestation | Logging | Mining | Pollution



Project Amazonia: Threats



  While the Amazon Rainforest remains the largest tropical rainforest in the world, deforestation from human activities threatens the continued existence of this astounding natural resource.  An estimated 5.4 million acres of tropical rainforest is being lost within Brazil each year2.  Unless measures are taken to slow the deforestation, it is questionable whether or not this resource will last beyond this generation.

            Outlined below are the key problems that deforestation causes to the Amazon Rainforest as well as the major causes of deforestation.  These causes and effects can be explored further by clicking on the links in the summaries below or by clicking on the navigation bar at the top of the page.

The Effects of Deforestation

            Because nutrients are absorbed so quickly by the flora in the Amazon, the soil in the Amazon retains very low amounts of nutrients.  As well, any decaying organic matter is quickly recycled into the ecosystem, leaving a very thin layer of organic material on the rainforest floor.  In fact, the primary nutrient layer of the soil in the Amazon is frequently only a few inches thick.

            When a portion of the forest is deforested, the root structure beneath the soil rapidly decays.  Without the support of the tree roots and the shelter of the canopy, the soil is left exposed to nature.  As a result, deforested lands have a far higher erosion rate than forested lands.  The little topsoil that had once supported the Amazonian flora is washed or blown away, leaving the remaining land even less fertile.

The Industrial Threat: Logging, Mining and Pollution

            Logging and mining, two common practices and means of employment in the Amazon, are also two of the most ecologically damaging activities within the rainforest.   Besides initiating the problems listed above, logging also causes the compaction of land and damming of streams, and encourages the creation of roads and immigration to surrounding areas.

            Mining also leads directly to the creation of transportation networks which in turn encourage increased immigration to the surrounding areas.  However, the procedures involved in mining also directly damage the land and surrounding wildlife.  Heavy machinery is used to clear an area for mining, and the act of mining tears a large hole in the earth.

            Once the rock reaches the refinery, the ore is separated from the host rock.  To achieve this separation, however, the refining process usually requires the use of cyanide and/or mercury.  These contaminants are known toxins, and many mining operations in the Amazon are improperly equipped to prevent the leakage of the toxins into the river.  As a result, surrounding flora and fauna are poisoned by the toxins leading to deformations, disease, and sometimes death.3

Brazilian Lifeblood: Infrastructure, Energy and the Amazon

            The creation of logging, mining and other industrial projects in the Amazon Rainforest ultimately requires the expansion of transportation networks within its depths.  However, the roads that are created to provide more facilitated access for industrial companies to work sites also provide easier access for immigrants to undisturbed depths of the Amazon.  As a result, road networks created from industrial projects typically leave a wake of deforestation surrounding the roads.

            Because the majority of Brazil's electricity is supplied by hydroelectric power plants within the Amazon Basin, infrastructure is required to ship the electricity to Brazil's urban centers.  This requires the setting up of enormous series of power lines and risks deforestation in the path of the power lines.

A Necessary Evil? - Food Production and Deforestation

            In an attempt to increase the fertility of the land, farmers in the Amazon frequently resort to slash-and-burn techniques, attempting to store the nutrients that were in the biomass of the forest within the soil.  However, the nutrients that are successfully pumped into the soil by this technique are rapidly eroded away by wind and rain and drain down into the clay layers beneath the topsoil.  The nutrients that remain in the soil are absorbed during harvests, leaving few nutrients to be returned the soil.  As a result, the land becomes virtually infertile after two or three crops and the farmers are required to move their operations to new lands, continuing the destructive cycle.

            Similarly, the preparation of Amazonian soil for ranching operations removes many of the nutrients from the system.  Remaining nutrients are used in the growing of grasses for the grazing cattle.  However, without a returning source of nutrients for the land, its viability decreases; overgrazing can be devastating to the fertility of the land.  The ranchers are forced to move and clear new land in order to maintain their ranching operations.


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1: No author. “The ARPA (Amazon Region Protected Areas) Project Overview: Report PID11197.”

2: National Remote Sensing Agency of Brazil (INPE); data provided in 1992 by Norbert Henninger, World Resources Institute, 1709 New York Avenue NW, Washington, D.C. 20006.

3: Lebel, Jean, “Mercury Poisoning in the Amazon: The tip of the Iceberg”, IDRC., Nov 26, 2002