Causes of Deforestation

Can You Spot the Cause?
Look at these pictures. Before reading on, can you identify the cause of deforestation?

One Cause: Forest Conversion to Agriculture
The forests on steep mountainsides shown in the pictures above were cut down for homes and fields. Such steep slopes are not good for growing corn and other food crops; the native vegetation cover is forest. However, increasing human demands for land pushes people and their crops higher and higher on the mountainsides.

"Corn is not worth cultivating."
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"This is the size of the corn, so you can see it's not worth cultivating," says Jose Luis Alvaez, pointing to a stubby ear of corn only 3 inches long.

Jose Luis is the Director of the Michoacan Reforestation Project (MRP). He explained that farmers are fighting a losing battle when they convert forest to agriculture. The expensive fertilizers needed on the poor soil make corn more expensive to produce that it’s worth. MRP encourages reforestation of these lands.

"70% of the natural land cover is forest in Michoacan."
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"Seventy percent of the natural land cover is forest in Michoacan. So that means that if you plant forests, you have no need for using insecticides, fertilizers or watering it because we have a perfect rainy season for forests."

Deforestation causes erosion, which muddies the water supply

Deforestation is also causing severe erosion. During the dry season it isn’t obvious how deforestation affects the water supply, but MRP’s Ed Rashin explains. "The water in this stream is running very clear right now, but if you were here during the rainy season what you’d see is a torrent of mud and water coming down from the eroded hillsides. That’s another reason why we need reforested land."

It is not only the monarchs who need the forests! "Local inhabitants, especially women, consider water scarcity their main environmental problem," say Monica Misserie and Lincoln Brower. "Water shortages during the dry months are becoming more and more critical."

In next week’s update, we’ll show how Journey North students are helping MRP's deforestation efforts in the monarch region.

Alternare Workshops Teach Soil and Water Conservation

The Mexican conservation organization "Alternare" works with the Monarch Reserve communities to help make farming methods more efficient and sustainable. Better farming practices in the valleys can reduce the need to grow crops on the mountainsides. This "before and after" photo shows the improvements made using organic fertilizer. The soil fertility increased and, at the same time, the use of chemical fertilizers was eliminated. The corn on the right was grown with organic fertilizer. One farmer was so happy with the results he said he wanted to "leave the chemicals and stop burning the earth," according to Alternare’s project evaluator.

National Science Education Standards

Life Science
Humans depend on their natural and constructed environments. Humans change environments in ways that can be either beneficial or detrimental for themselves and other organisms. (K-4)

Earth Science
Soils have properties of color and texture, capacity to retain water, and ability to support the growth of many kinds of plants, including those in our food supply. (K-4)

Science in Personal and Social Perspectives
Resources are things we get from living and nonliving environment to meet the needs and wants of a population. (K-4)

Some resources are basic materials, such as air, water, and soil; some are produced from basic resources, such as food, fuel, and building materials; and some resources are nonmaterial, such as quiet places, beauty, security, and safety. (K-4)

Changes in environments can be natural or influenced by humans. Some changes are good, some are bad, and some are neither. (K-4)

Human activities also can induce hazards through resource acquisition, urban growth, land-use decisions, and waste disposal. Such activities can accelerate many natural changes. (5-8)

National Geography Standards

Places and Regions
The physical and human characteristics of places.

Environment and Society
How human actions modify the physical environment.