Chapter 7: Review Questions

225

Question 1

1. Which of the following ecosystems is most likely to support the highest level of primary production?

  1. Tropical forest

  2. Temperate forest

  3. Hot desert

  4. Temperate grassland

Question 2

2. Which of the following soil horizons generally contains the lowest amount of organic matter?

  1. O horizon

  2. A horizon

  3. B horizon

  4. C horizon

Question 3

3. Why do tropical forest soils generally contain low amounts of organic matter?

  1. Low levels of primary production by tropical forests

  2. Lack of decomposition of organic matter in tropical forests

  3. High rates of decomposition of soil organic matter

  4. An absence of soil animals, such as ants, in tropical forests

Question 4

4. Which of the following is a major source of erosion in forests?

  1. Road building

  2. Wildfires

  3. Soil disturbance by heavy equipment

  4. All of the above

Question 5

5. In which of the following situations would irrigation most likely produce soil salinization?

  1. In soils with high rates of drainage and low levels of irrigation water inputs

  2. In soils with low rates of drainage and high levels of irrigation water inputs

  3. In soils with a low (deep) water table

  4. In sandy soils with high rates of leaching

Question 6

6. The individuals carrying genes for pesticide resistance are generally rare in a pest population prior to exposure to a pesticide. What does this suggest about the pesticide-resistant individuals in the population?

  1. Pesticide-resistant individuals are at a competitive disadvantage relative to other individuals in the population in the absence of the pesticide.

  2. Pesticide-resistant individuals are at a competitive advantage relative to other individuals in the population in the presence and absence of the pesticide.

  3. Pesticide-resistant individuals are at a competitive disadvantage relative to other individuals in the population in all environments.

  4. There are no differences in competitive ability between pesticide-resistant individuals and pesticide-sensitive individuals.

Question 7

7. What determines whether a genetically modified organism (GMO) is transgenic?

  1. It carries genes different from wild ancestors.

  2. It is more resistant to attacks by insects.

  3. It grows at faster rates than other varieties.

  4. It carries a gene from another species.

Question 8

8. Which of the following was not part of the Green Revolution?

  1. Use of pesticides

  2. Conventional tillage

  3. Genetically modified crops

  4. Intensive plant breeding programs

Question 9

9. Which of the following approaches to farming will generally have the lowest fuel costs?

  1. Conventional tillage farming

  2. Low-till farming

  3. No-till farming

  4. All approaches to farming have similar fuel costs.

Question 10

10. Which of the following is not part of IPM?

  1. Closely monitoring the size of pest populations

  2. A graded response to increasing pest populations, beginning with trapping

  3. Preventative measures such as planting pest-resistant crop varieties

  4. Eventually eradicating pest populations with chemical sprays

Critical Analysis

Question 1

1. Why do some environmental observers say that the impact of intensive agriculture is really a population problem rather than a problem with agriculture?

Question 2

2. At the height of the Dust Bowl (see Figure 7.12, page 199), U.S. President Franklin D. Roosevelt said, “The nation that destroys its soils destroys itself.” Explain his rationale.

Question 3

3. How are the concepts of evolutionary biology, community ecology, and ecosystem ecology increasingly informing today’s agriculture?

Question 4

4. Refer to Figure 4.3 (page 99), Figure 7.4 (page 193), and Figure 7.6 (page 195), summarizing the global distribution of biomes, climates, and soils. Discuss the influence that these factors may have had on the development of agriculture.

Question 5

5. Develop a detailed conceptual design for farming sustainably on land requiring irrigation for crop production.