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Section 8.2: How We Use Land PowerPoint Presentation
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Section 8.2: How We Use Land

Section 8.2: How We Use Land

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Section 8.2: How We Use Land

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  1. Section 8.2: How We Use Land • Vocabulary • Deforestation: clearing trees from an area without replacing them (pg.205) • Clear Cutting: method of harvesting trees in which all of the trees are removed from a land area, as opposed to selective cutting (pg.205) • Selective Cutting: method of harvesting only middle-aged or mature trees individually or in small groups (pg. 206 • Reforestation: process of replacing trees that have died or been cut down (pg.206) • Overgrazing Mineral: damage to grassland caused by too many animals eating in a limited area; often so harmful that the grass cannot recover (pg. 208) • Mineral Resources: minerals that have economic value and are useful to humans in some way (pg. 210) • Open-pit Mining: method of mining in which large holes is dug in the ground to remove materials such as ore, sand, gravel, and building stone (pg. 210) • Strip Mine: method of mining in which huge machines clear away large strips of the Earth’s surface, as in phosphate mining (pg.210) A fairly successful Reforestation effort.

  2. Section 8.2: How We Use Land (cont.) • Most of the resources needed in urban areas come from the world’s non-urban and rural areas. • Non-urban lands include forests, rich grasslands, and mining sites. • Unfortunately, many of these non-urban lands are destroyed or damaged because of overuse. • We harvest trees to make paper and furniture, and the average person uses enough of these to add up to a thirty meter tall tree. • Firewood is needed by many people; in fact 1.5 billion people in developing countries depend on firewood as fuel. • In other countries, the trees are disregarded and cut down, because the people want to use the fertile soil and land to harvest and farm. Also to make roads and businesses. • Deforestation is clearing trees from an area without replacing them, and is a big problem. Rain Forests are being cut down and the ground is used only for a short time, because the soil is not fertile enough for permanent farming. • When people harvest trees, the majority clear-cut, which means remove all the trees from a certain areas. Not only does this destroy the trees and land but it kills wildlife. • Another and preferred method of cutting down trees is called Selective Cutting, which results in only chopping down a specific type of tree or trees in an area, leaving others alone. Deforestation is a global environmental issue.

  3. Section 8.2: How We Use Land (cont.) • Selective Cutting allows the trees to grow back naturally. • Reforestation is the process of replacing already chopped down trees, but can only be done with trees cut down from Selective Cutting. • 90% of the world’s lumber comes from forests not monitored by the government. • Many governments are working to protect the forests, creating different programs and laws. • Rangelands consist of shrubs and grasses, and are home to many livestock that are important to the world’s food. • The dangers of the rangelands include their susceptibility to grass-fires and droughts. However, this is only a danger to humans because these plants can keep growing right throw the hard times. • Even though the grasses are adaptable, overgrazing is one thing that can instantly limit their amounts. • As the grasses die, their roots decay, and this process leads to desertification, which converts rangeland to wasteland. • The Public Rangelands Improvement Act of 1978 has helped manage rangelands, but still rangelands find themselves victim to overuse and overgrazing. A Timber Forest after Selective Cutting.

  4. Section 8.2: How We Use Land (cont.) • A very large amount of land is used for mining minerals, which can be formed into many of the different materials we have today. • There are two types of methods of mining: open-pit mining and strip mining. • In open-pit mining, machines dig large holds into the ground and remove the ore and other minerals. • In strip mining, huge bulldozers and other machines clear away large strips of the Earth’s surface. Many raw materials are found this way. • Mining leaves long-lasting effects on Earth, and causes environmental damage. While habitats are cleared away for a mining spot, the mines leave behind a lot of waste and the area’s ecosystem is ruined. • Every year the amount of waste increases because the miners have to dig deeper and deeper to find the right resources. • In an effort to maintain the damages caused by mining, a system called reclamation has been developed. After the land has been used for the mining and work needed, the mining company must fill the hole back up and replace the earth, while planting trees and plants again. • Another way to reduce mining is to limit the need for more minerals. This can be achieved through recycling and reusing. An example of an open-pit mine.