Here's an easy question for you: how do people use the natural environment?
In west-central Mexico, the Purhepecha people of the Patzcuaro Lake Basin adapted their culture to their environment. Traditionally, they used wood from the local forests for fuel and to make crafts. Also, they used the lake to get fish (check out the picture on the 50 peso bill). The Purhepecha adapted their agriculture to their environment, too. When they would plant crops on hillsides, the Purhepecha would build terraces to prevent erosion. Besides that, they would plant a combination of corn, beans, and vegetables that would keep the soil healthy. (Beans add the nitrogen to the soil that the other crops take out when they grow.)
A woodcarving in Tzintzuntzan, a village along Lake Patzcuaro and the capital of the ancient Purhepecha civilization.
A fisherman using a traditional butterfly net on Lake Patzcuaro. This picture is on the back of the 50 peso bill.
How do people change the natural environment?
People can change the natural environment in many ways. We can build schools, make bike trails, and plant crops, also we can clear-cut forests, pollute streams, and throw trash out of car windows.
During the 16th century, the Spanish missionary Vasco de Quiroga changed the natural landscape of the Patzcuaro Lake Basin by building hospitals, schools, and churches for the local Purhepecha Indians. This didn't have a huge environmental impact, but the towns and haciendas build by the Spanish did.
In 1886, the railroad arrived in the basin. After that, people started intensively logging the forests around Lake Patzcuaro. They used the lumber to make railroad ties. Also, they sent lumber to cities by train to be used for construction.
Logging has changed the environment around Lake Patzcuaro in two main ways. Obviously, there aren't as many trees around anymore (only 34% of what there used to be). But, besides that, logging is causing Lake Patzcuaro to fill up with silt. Normally, plants and trees hold the soil in place. Without the trees, though, the soil washes down into the lake during the yearly rainy season.
People on farms and in cities have changed the Patzcuaro Lake Basin's environment, too. In fact, these people are unintentionally working together to kill the fish in the lake. Today, farmers use chemical fertilizers to increase their crop production. But, when it rains, these chemicals get washed down to the lake and cause algae and other aquatic plants to grow. Chemical and organic wastes from open garbage dumps get washed down to the lake, too. With all of these available nutrients, large amounts of algae and other aquatic plants are growing on the bottom of the lake. Unfortunately, that is bad news for the fish. As bacteria decompose these plants, the bacteria use up the oxygen that the fish need to live. With the oxygen used up at the bottom of the lake, fish have less space to live in. Plus, every so often, the lake water turns over, and the oxygen-deprived water from the bottom of the lake moves up to the top and kills large amounts of fish.
A statue of Vasco
de Quiroga in Tzintzuntzan.
He changed the landscape by building
hospitals, schools, and churches.
A polluted stream in Patzcuaro. Chemical and organic wastes that wash down to the lake can cause algae and other plants to grow.
Environmentalists
say that evaporation, extraction of water, erosion, and chemical runoff
are causing Lake Patzcuaro to shrink.
Map provided by Center for Social and Ecological Studies,
Patzcuaro
Farmland that used to be covered by Lake Patzcuaro.
How does environmental change affect people?
Everybody is affected when the environment changes. Around Lake Patzcuaro, the fishermen can't fish as much because of changes made to the lake. Farmers are affected by environmental change too. The more they use chemical fertilizers to increase crop production, the more the soil gets worn out. This is because the soil isn't getting the organic material that it uses to hold water and to keep a good structure and that microscopic organisms break down to produce nutrients. As soil quality goes down, so do crop yields (unless they buy even more chemical fertilizers for their land). When people can't make money fishing or farming around Lake Patzcuaro, they move to cities, the United States, or Canada to find jobs. Even the people that don't move or lose their ways of life are affected by environmental change because their friends and family members are constantly leaving.
Janitzio Island in Lake Patzcuaro. As people leave to find work, some villages in the Lake Patzcuaro Basin only have half the number of men that they did ten years ago.
What can people do about environmental change?
People can do a lot of things to prevent and stop negative environmental changes.
In the Patzcuaro Lake Basin, people are combating deforestation by planting more trees. Also, they are fighting erosion by building filtering dams that stop the soil from being carried down to the lake during the rainy season. Besides that, two landfills and two sewage treatment centers have been built to stop the pollution of the lake. Finally, environmental groups are working to educate people about the consequences of their actions. They are encouraging people to recycle more, to use less, and to work together so that some people don't make environmental decisions that will hurt others.
Just like in the Patzcuaro Lake Basin, we need to work together to make our world one worth living in.
A group of hikers on a filtering dam. Money earned from eco-tours like this one and from a Spanish language school in Patzcuaro go towards environmental and community organizing work in the region.
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References:
Barrett, Elinore. 1980. Indian Community Hospitals in Colonial Michoacan. In Historical Geography of Latin America, eds. W.V. Davidson and J.J. Parsons, pp. 63-73. Baton Rouge: School of GeoScience, Louisiana State University.
Bradshaw, Michael and Ruth Weaver. 1993. Physical Geography: An Introduction to Earth Environments. St. Louis, Missouri: Moby-Year Book.
Burton, Tony. 1997. Can Mexico's Largest Lake be Saved?, http://mexconnect.com/mex_/travel/tonysarticles/tblagunasaded.html, accessed 8/6/2002.
Burton, Tony. 2000. Can Mexico's Largest Lake be Saved?A Year 2000 Update: The State of the Lake, http://mexconnect.com /mex_/travel/tonysarticles/ tblagunasaded2.html, accessed 8/6/2002.
Burton, Tony. 2001. Can Mexico's Largest Lake be Saved? A Year 2001 Update: The Future of Lake Chapala: Suggestions for Discussion, http://mexconnect.com/ mex_/travel/tonysarticles/tblagunasaded.html, accessed 8/6/2002.
Davenport, Merle. 1998. Eastern Africa: An Interdisciplinary Unit. Grand Rapids, Michigan: Instructional Fair-TS Denison.
Esteva, Joaquin. 1995. The Restoration of a Lake Basin in Mexico and the Regional Social Participatory Process: The Case of ORCA. Morelia, Mexico: Center for the Social and Ecological Studies.
Herrera, Raul. 2001. Personal Communication. Center for Languages and Ecotours of Patzcuaro. Patzcuaro, Mexico.
Magner, James A. 1968. Men of Mexico. New York: Books for Libraries Press.
Sams, Clint. 2002. Personal Communication. Agriculture Program, Othello High School. Othello, Washington.
Sarre, Philip and John Blunden. 1996. Environment, Population and Development. Frome, Somerset, UK: Hodder & Stoughton.
Toledo, Victor M. 1996. Plan Patzcuaro 2000: Presentacion, Objectivos, Propuestas. Morelia, Mexico: SEMARNAP.
Toledo, Victor M. Todos Podemos Salvar El Lago de Patzcuaro. Programa de Naciones Unidas para el Desarrollo.