6.2 Using Resources Wisely
Why is soil important, and how do we protect it?- What are the primary sources of water pollution?
- What are the major forms of air pollution?
desertification
deforestation
pollutant
biological magnification
smog
acid rain
Concept Map As you read, create a concept map to organize the information in this lesson.
THINK ABOUT IT Our economy is built on the use of natural resources, so leaving those resources untouched is not an option. Humans need to eat, for example, so we can't just stop cultivating land for farming. But the goods and services provided by healthy ecosystems are essential to life. We can't grow anything in soil that has lost its nutrients due to overfarming. If we don't properly manage agriculture, then, we may one day lose the natural resource on which it depends. So how do we find a balance? How do we obtain what we need from local and global environments without destroying those environments?
Soil Resources
Why is soil important, and how do we protect it?
When you think of natural resources, soil may not be something that comes to mind. But many objects you come into contact with daily rely on soil—from the grain in your breakfast cereal, to the wood in your home, to the pages of this textbook. Healthy soil supports both agriculture and forestry. The mineral- and nutrient-rich portion of soil is called topsoil. Good topsoil absorbs and retains moisture yet allows water to drain. It is rich in organic matter and nutrients, but low in salts. Good topsoil is produced by long-term interactions between soil and the plants growing in it.
Topsoil can be a renewable resource if it is managed properly, but it can be damaged or lost if it is mismanaged. Healthy soil can take centuries to form but can be lost very quickly. And the loss of fertile soil can have dire consequences. Years of poorly managed farming in addition to severe drought in the 1930s badly eroded the once-fertile soil of the Great Plains. Thousands upon thousands of people lost their jobs and homes. The area essentially turned to desert, or, as it came to be known, a “dust bowl,” as seen in Figure 6–5. What causes soil erosion, and how can we prevent it?
FIGURE 6–5 The Dust Bowl A ranch in Boise City, Idaho, is about to be hit by a cloud of dry soil on April 15, 1935.
Table of Contents
- Formulas and Equations
- Applying Formulas and Equations
- Mean, Median, and Mode
- Estimation
- Using Measurements in Calculations
- Effects of Measurement Errors
- Accuracy
- Precision
- Comparing Accuracy and Precision
- Significant Figures
- Calculating With Significant Figures
- Scientific Notation
- Calculating With Scientific Notation
- Dimensional Analysis
- Applying Dimensional Analysis