Review of Main Concepts
These chapters focus on human populations, and the food and systems needed to
support people. Chapter 8 discusses the factors that lead to population change and the problems of overpopulation. Chapters 17 and 18 consider land and agriculture. They discuss the different was we use land and the different resources land provides. One of the most important uses of land is for food (agricultural) production.
Chapter 8: The Human Population
Populations grow when the number of individuals added (by birth or immigration) is greater than the number of individuals removed (by death or outmigration). Many factors affect the birth rates and death rates, including environmental resource availability and interactions with other species such as predators or prey.
Human populations go through several demographic stages as the society changes. Changes in social factors such as the type of economy (agricultural vs. industrial), health care, and education affect the birth and death rates, and, therefore, the overall dynamics of the population.
Be able to explain key features of the demographic transition graph (figure 8.14) such as: what are some of the reasons for the trend in birth and death rates in each of the stages? What is the relationship between the birth rates, death rates and size of the population in general, and at any given point?
Give examples of countries that might be in each of the stages.
How does socioeconomic status and women's rights affect population dynamics?
Human population size affects the amount of resources we consume globally. Extracting resources damages the environment, which reduces the Earth's carrying capacity, which is its ability to provide us with resources. Resource availability, in turn, affects population growth.
Global human population is currently growing at an exponential rate. Since exponential growth cannot be sustained forever, what are two possible scenarios for the population curve in the future as it approaches the earth's carrying capacity?
What would cause an ecosystem's carrying capacity to decrease?
Explain how a country with a smaller population could have a greater environmental impact than a country with a larger population.
Chapter 17: Land Resources
List the major types of land uses in the world.
What percent of the world's land area is used for cities?
What percent of the world's land area is used for agriculture (crops and pasture)?
Describe the role that forests play in the global water, carbon, and nutrient cycles.
Identify at least 3 other ecosystem services provided by forests.
Be able to explain the likely consequences of large-scale deforestation.
Describe current threats to coastal and freshwater wetlands.
Chapter 18: Food Resources: A Challenge for Agriculture
A growing population increases the global demand for food. The environment provides us with food resources through agriculture. However, agriculture activities also affect the environment by degrading water and soil resources. This degradation also affects human health.
What are the differences between the environmental impacts of industrialized agriculture versus subsistence agriculture?
How do pesticides and fertilizers affect environmental health?
What are some alternatives to the use of chemical pesticides and fertilizers? Why are they considered more environmentally friendly?
How do agricultural activities affect soil and water quality?
What are reasons for and against the use of hormones and antibiotics in agriculture?