Alternative Strategy:
Middle and Senior School Potential
Alternative Strategy:
Middle and Senior School Potential
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Following are two readings taken from the Internet case study of deforestation in one area of the world, the Amazon region of Brazil. Reproduce the articles and distribute to students. The goal of the lesson is to try to help students understand the relationship between the effects of deforestation in one area, with the larger issues of global implications. A basic chart form designating LOCAL IMPACT and GLOBAL IMPACT might be organized around the major scientific and economic findings. Discuss the Amazonian example, clearly using geographic location, scientific information, and human interactions as keys to helping students to understand the basic notion of deforestation. Then, using the reading concerning ALTERNATIVES, have students weigh the theoretical and practical aspects of the alternatives, from the points of view of the various interested parties in Brazil, as well as those from other areas of the world concerned about the broader global implications.
Reading I Amazon Deforestation and Global Environmental Phenomena Over half of the world's tropical rain forests have already been destroyed, most of which are in Brazil, and they are continuing to be destroyed today (Domroes, 1991). When the topic of tropical rain forest destruction is raised it usually brings to mind issues of biodiversity and hidden cures for cancer, both of which are important reasons to end deforestation. However, one issue which is often left out is the tropical rain forests' part in global climate and the greenhouse effect. This is an issue which surpasses regional boundaries, that effects the atmosphere as well the biosphere. Causes of Deforestation Tropical forests are destroyed for several reasons, each of which have both similar and differing ecological consequences, none of which are beneficial. There is an ever increasing demand for both farm and grazing land which results in the burning and clearing of rain forests for agriculture production. Another cause of deforestation is the continued urbanization of the world and thus the need for construction of roads and industrialization. The need for fuel and timber for construction is another major factor leading to the destruction of the rain forest (Domries, 1991 and Salati, 1991). Effects of Deforestation The actual extent of the role that the rain forest and its subsequent deforestation play in global climate and its changes is difficult to gauge. This is one reason why there has been a lack of media coverage about the subject outside of the scientific community. There are numerous variables involved in changing weather patterns such as global warming and only recently have we begun to develop sufficient computer simulation models, such as those used in Shukla's article done at the Center for Ocean-Land-Atmosphere Interactions at the University of Maryland, to accurately predict what affect one regions climate will have on another region's. Another problem is that each model and each scientist is set towards a different agenda which can often lead to different results. These differing statistics lend themselves to a great deal of debate about numbers rather than issues, slowing down the scientists and communities ability to act. Despite this, there are certain truths which cannot be ignored, whether the figures are varied or not. Carbon dioxide accounts for at least one half of the greenhouse effect, in which atmospheric gases, mostly produced by human activities, trap the sun's heat, slowly warming the Earth (Myers,1991). Deforestation by burning accounts for up to 25% of the annual global CO 2 emissions (Salati, 1991). Trees are half carbon and by burning them we release all of that carbon into the atmosphere. At least three-quarters of deforestation in the tropics is due to burning, which releases about 2.4 billion tons of CO 2 into the atmosphere each year (Myers, 1991). The greenhouse effect will have several affects on global ecology, one of which is rising sea levels due to things such as the melting of several large glaciers. This could affect coastal communities through more frequent flooding and increased soil salinity (IUCC, 1993). As well, there could be implications for the organisms which live in the sea, especially if the warming of the atmosphere leads to a subsequent warming of ocean temperatures. According to the Information Unit on Climate Change, a change in climate caused by greenhouse gases would have great affects on future agriculture as well. (1993) The other affects of deforestation on climate are more regional but no less important. Several different models and studies indicate that deforestation will lead to a reduction in average rainfall and increased surface temperature (Hastenrath, 1991 and Shukla, 1990). Because the top soil in rain forests is so thin, it lends itself to rapid soil erosion. Without the trees there to act as a buffer between the soil and the rain, erosion is practically inevitable. Soil erosion then leads to greater amounts of run off and increased sedimentation in the rivers and streams. The combination of these factors leads to flooding and increased salinity of the soil (Domries,1991 and Hastenroth,1991). Solutions and Conclusions While rain forest destruction has been slowed during the last decade it still continues at an alarming rate and needs to be discontinued entirely. Scientists have begun to show that reforestation can actually decrease the patterns of global warming by fixing the carbon dioxide in the atmosphere (Myers,1991). A great deal of research still needs to be done on these aspects of deforestation as well as the interaction of the varying regions on global climate but preliminary studies such as those done by Shukla and Myers show that it should be one of our major concerns today and that we need to research feasible solutions to these problems. Source:
Reading II Alternatives to Deforestation in the Amazon Basin The forest is one of the most complex and least understood ecosystems on our planet. The forests of the world are our greatest storehouse of biological diversity. They also regulate climate, protect the soil, act as watersheds for some of the worlds major aquatic systems, and provide habitat for an incredible variety of organisms ranging from fish to human beings. Several million acres of tropical forest are destroyed each year with great repercussions for all organisms within the complex forest web of life. Current deforestation practices, such as converting rainforests into pastures and fields, along with clear cutting for timber, yield higher net revenues than those that can be obtained by sustainable harvesting of natural forest products. Our current perception is that with the exception of a few specific goods, the rain forest has little economic value. The question is how to change this perception in order to promote sustainability and further development of the various organisms within the rainforest. In the following pages I will present several solutions that can help sustain biological diversity while yielding comparable or better revenues than that of current deforestation practices. Rainforest trees are hosts to produce, fruits, spices, edible oils, medicines, and fibers. They also produce a wide assortment of industrial compounds such as latex, rubber, dyes, and resins. Only a few rain forest products are traded on the international market, products like Brazil nuts, rubber, rattan, and illie oil (an important ingredient in cocoa butter and cosmetics). Most of these products are harvested for sustainability and trade in local markets. These products should be introduced to international markets with the other products that are already traded internationally. "Based on an assumption of sustainable harvest and annual fruit and latex collections, we estimate that the combined financial worth of the tree resources growing in one hectare of rain forest at Mishana is almost $7000. Surprisingly, this result is more than three times the net recent value of a fully stocked cattle pasture in the amazon and almost twice that of an intensely managed timber plantation. Far from being a worthless tangle of vegetation that must be eliminated to yield profit, sustainable forest exploitation at Mishana would actually generate higher net revenues than almost any other type of land use (Peters, 1990)." Many local people in Amazonia depend on agriculture for their livelihood, but most of them practice unsustainable agriculture. If there is to be any restoration of the biological diversity of a watershed area we must incorporate more productive and sustainable agricultural systems that benefit both villagers and other organisms that share the ecosystem. Examples of more productive agricultural systems: Contour Farming/Alley-cropping where slash and burn farming permitted one or two harvests every eight years, contour planting of "Alley-Crops" between hedgerows of trees permits continuous farming of the land, with much higher annual yields. The farmer gets this productivity sustainability, without additional expense for commercial fertilizer or other chemicals. One acre produces eight times as much per year as before. Confinement Rearing where open grazing supported one cow on eight acres of fragile hillsides, confinement rearing that includes forage trees allows one acre to support as many as twenty cattle, increasing the growth rates of the animals three times! The animals themselves are kept of the land so that desertification is avoided. Family Woodlots where "looping" of trees for firewood and forage required an average of fifty working hours per household per week and rapidly destroyed the forests, fast growing fuel wood trees allow a continuous harvest of firewood sufficient for family needs, on a small area of untillable land at the family homesite. Watershed Improvement where upland springs failed as the forest were cleared, planting wood lots above the springs permits a return of wildlife and native tree species and, within two years, can bring a spring back to life. (New Forest Project, 1989) These alternative systems can help preserve the aquatic systems and land organisms of the rain forest, by reducing pressure on the land caused by human consumption. After these practices are implemented the natural forces of mother nature can take over. After all no one can plant trees better than mother nature, especially if she has a little help. Source:
Limited Bibliography Colonization in the Amazon Basin _____.(1994). Amazonia por la Vida: Una Guia ambiental para la Defensa del Territorio Amaznico Amenazado. Quito-Ecuador, Accion Ecolgica. Almeida, Anna Luiza Ozorio de (1992). The Colonization of the Amazon. Austin, University of Texas Press. Bittencourt, Ricardo de (1994). Environment-Brazil: Water, Today" Greatest Challenge. Interpress Service, via Lexis/Nexis/Medis. Downing, Theodore E. et al. (1992). Development or Destruction. Boulder, CO, Westview Press. Kimmerling, Judith(1994). Crudo Amaznico. Quito-Ecuador, Ediciones ABYA-YALA. Lama, Abraham (1995). Peru-Environment: Deforestation a One-Way Street? Interpress Service, via Lexis/Nexis/Medis.Rainforest Action Network<http://www.igc.apc.org/ran> (1995). Shumatoff, Alex (1990). The World is Burning. Boston, Little, Brown & Co. Skole, D.L. et al (1994). Physical and Human Dimensions of Deforestation in Amazonia. Bioscience Magazine, May 1994. American Institute of Biological Sciences via Lexis/Nexis/Medis. Turner, Monica G. (1995). Ecological Dynamics at Broad Scales: Ecosystems and Landscapes. Bioscience, June 1995, via Lexis/Nexis/Medis.
Amazon Deforestation and Global Environmental Phenomena Domroes, M. (1991). "The Tropical Forest Ecosystem: Reviewing the Effects of Deforestation on Climate and Environment." The Global Environment. Ed. K. Takeuchi and M Yoshino. Berlin: Springer- Verlag. 70-80. Hastenrath, Stefan (1991). Climate Dynamics of the Tropics. Boston: Kluwer Academic Publishers. Information Unit on Climate Change (1993). "An Introduction to man-made climate change." World Scientists’ Warning Briefing Book. Ed. Union of Concerned Scientists. Cambridge: Union of Concerned Scientists. 17-18. ____. (1993). "The Impact of climate change on agriculture." World Scientists Waring Briefing Book. Ed. Union of Concerned Scientists. Cambridge: Union of Concerned Scientists. 19-20. Myers, Norman. (1991). "Trees by the Billions: A Blueprint for Ecology." International Wildlife. 21.5: 12-15. Salati, E. et al. (1991). "Forests: Their Role in Global Change, with Special Reference to the Brazilian Amazon." Climate Change: Science, Impacts, and Policy. Proc. of the 2nd World Climate Conference. Ed. J. Jagar and H.L. Ferguson. New York: Cambridge Univ. Press. 391-394. Shukla, J., C. Nobre, and P. Sellers (1990). "Amazon Deforestation and Climate Change." Science 247: 1322-1325.
Alternatives to Deforestation Edward O. Wilson (1989). Managing Planet Earth, "Threats to Biodiversity." Readings from Scientific American Magazine. W. H.. Freeman And Company New York. Charles M. Peters (1990). Global Resources Opposing Viewpoints, "Alternative Agriculture Will Achieve Sustainability." Greenhaven Press Inc. National Research Council (1989). Global Resources Opposing Viewpoints, "Alternative Agriculture Will Achieve Sustainability." Greenhaven Press Inc. Source: |
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