Chapter 14 - The ecology of human population growth, disease, and food supply

Question 2

What is Aquaculture?

Answer 2

The farming of fish, shellfish, and other aquatic organisms in controlled environments.

Question 3

What is Biomagnification?

Answer 3

The increasing concentration of a substance, such as a toxic chemical, in organisms at successively higher levels in a food chain.

Question 4

What are Biofuels?

Answer 4

Energy sources developed from biomass derived from agriculture or natural ecosystems, such as ethanol or biodiesel.

Question 5

What is Carrying Capacity?

Answer 5

The maximum population size of a species that the environment can sustain indefinitely, given the available resources.

Question 6

What is Classical (Importation) Biological Control?

Answer 6

A form of biological control that involves importing a known natural enemy from another geographic area to control a pest species.

Question 7

What is Conservation Biological Control?

Answer 7

A form of biological control that aims to increase the effectiveness of natural enemies already native to the region where a pest occurs.

Question 8

What is Cultural Eutrophication?

Answer 8

The process by which excess inorganic nutrients, primarily from agricultural runoff and human sewage, lead to the excessive growth of algae and other aquatic plants, often resulting in oxygen depletion (dead zones).

Question 9

What is Demographic Transition?

Answer 9

The process of change in a society’s population from a condition of high birth and death rates to a condition of low birth and death rates.

Question 10

What is Desertification?

Answer 10

The process by which arid or semiarid land becomes desert, often due to unsustainable land use practices and climate change.

Question 11

What is Dieldrin?

Answer 11

A persistent organic pollutant insecticide mentioned as having significant negative impacts on wildlife and livestock.

Question 12

What was the Dust Bowl?

Answer 12

A period in the 1930s in the Great Plains region of the United States characterized by severe dust storms caused by drought and unsustainable agricultural practices.

Question 13

What is an Ecological Footprint?

Answer 13

A measure of the amount of land and water area a human population requires to produce the resources it consumes and to absorb its wastes.

Question 14

What is Economic Injury Level (EIL)?

Answer 14

The pest population density at which the cost of artificial control measures is equal to the value of the crop losses that would occur if the pest population were not controlled.

Question 15

What is Fixed Effort?

Answer 15

A fisheries management approach where the amount of fishing effort (e.g., number of boats or fishing time) is limited.

Question 16

What is Fixed Quota?

Answer 16

A fisheries management approach where a predetermined amount of fish is allowed to be caught each year.

Question 17

What is Guano?

Answer 17

The accumulated feces and urine of birds or bats, a rich source of nitrogen and historically used as fertilizer.

Question 18

What is the Haber-Bosch Process?

Answer 18

An industrial process that synthesizes ammonia from nitrogen gas and hydrogen gas, a key method for producing synthetic nitrogen fertilizer.

Question 19

What are Herbicides?

Answer 19

Pesticides used to control unwanted plants (weeds).

Question 20

What is a Hypoxic ‘Dead Zone’?

Answer 20

An area in a body of water where oxygen levels are too low to support most aquatic life, often caused by nutrient pollution.

Question 21

What are Insecticides?

Answer 21

Pesticides used to control insects.

Question 22

What is Integrated Pest Management (IPM)?

Answer 22

A pest control strategy that combines various methods, including biological, cultural, physical, and chemical controls, in a way that minimizes economic, health, and environmental risks.

Question 23

What are Leguminous Plants?

Answer 23

Plants, such as beans, peas, and clover, that have symbiotic bacteria in their roots that can fix atmospheric nitrogen, enriching the soil.

Question 24

What is Maximum Sustainable Yield (MSY)?

Answer 24

The largest yield that can be taken from a species’ stock over an indefinite period.

Question 25

What is Monoculture?

Answer 25

The cultivation of a single crop over a large area.

Question 26

What are Nitrification Inhibitors?

Answer 26

Substances that slow down or prevent the conversion of ammonium to nitrate in the soil.

Question 27

What is Nitrous Oxide?

Answer 27

A greenhouse gas and ozone-depleting substance, the atmospheric concentration of which has increased due to the acceleration of the global nitrogen cycle by human activities.

Question 28

What is Overexploitation?

Answer 28

Harvesting a renewable resource at a rate that exceeds its ability to replenish itself, leading to population decline.

Question 29

What is Panama Disease?

Answer 29

A fungal disease that caused the collapse of the Gros Michel banana industry.

Question 30

What is a Pest?

Answer 30

A species that humans consider undesirable, often because it damages crops, livestock, or property.

Question 31

What are Pesticides?

Answer 31

Substances used to kill or control pests.

Question 32

What are Potential Pests?

Answer 32

Species that are typically kept below their economic injury level by natural enemies but can become pests if those enemies are removed.

Question 33

What is the Precautionary Principle?

Answer 33

The principle that calls for caution in taking any action when the results are uncertain but the potential dangers are highly serious.

Question 34

What is Salinization?

Answer 34

The process of salt accumulation in the topsoil, often in irrigated arid and semiarid regions, making land difficult to use for agriculture.

Question 35

What are Secondary Pests?

Answer 35

Species that become pests after the application of a pesticide eliminates their natural enemies.

Question 36

What is Slash and Burn Agriculture?

Answer 36

A method of agriculture in which forests are cleared by cutting and burning, which enriches the soil with nutrients for a short period.

Question 37

What is Target Pest Resurgence?

Answer 37

The rapid increase in the population of a target pest after pesticide application, often due to the elimination of the pest's natural enemies.

Question 38

What are Tropical Nights?

Answer 38

Nights when the temperature remains above 20°C, a metric used to track warming trends.

Question 39

What is Urbanization?

Answer 39

The increasing proportion of a population that lives in cities and towns.

Question 40

What is a Winter Cover Crop?

Answer 40

A secondary crop planted in the fall and harvested in the spring, used to protect soil and assimilate nutrients during the non-growing season for the primary crop.

Question 41

What are the major components of terrestrial mammal biomass on Earth today?

Answer 41

The major components of terrestrial mammal biomass are humans, livestock, and wild animals. Wild animals constitute a very small proportion (less than 3%) compared to the large biomass of humans and livestock.

Question 42

What is the demographic transition?

Answer 42

The demographic transition describes the shift in population growth patterns as a country develops, moving from high birth and death rates to low birth and death rates, often resulting in a period of significant population increase.

Question 43

How does increased affluence in developing countries impact protein consumption?

Answer 43

Increased affluence often leads to increased consumption of animal products. This can lead to the intensification of animal agriculture, which causes significant environmental damage, particularly through increased nitrogen pollution.

Question 44

What are two agricultural practices that contribute to downstream nitrogen pollution?

Answer 44

Two other agricultural practices contributing to nitrogen pollution are planting winter cover crops to assimilate soil nitrate and treating soils with nitrification inhibitors to prevent ammonium from converting to readily leached nitrate.

Question 45

Why are agricultural monocultures particularly susceptible to pest outbreaks?

Answer 45

Agricultural monocultures encourage pests because they provide a large, concentrated, and predictable food source for a specific pest species, allowing their populations to grow unchecked without the diversity of natural enemies found in more varied ecosystems.

Question 46

What is biomagnification and why is it a concern regarding pesticide use?

Answer 46

Biomagnification is the increasing concentration of a compound in the tissues of organisms as it passes up the food chain. This is a concern with pesticides because toxins can accumulate to harmful levels in organisms at higher trophic levels, including humans who consume contaminated fish or meat.

Question 47

What is target pest resurgence?

Answer 47

Target pest resurgence occurs when a pesticide kills a large number of both the pest and its natural enemies. With fewer natural enemies, the surviving pests have abundant food and little predation, leading to a rapid increase in their population.

Question 48

What is Integrated Pest Management (IPM)?

Answer 48

IPM is a strategy that uses a combination of methods to control pests, including monitoring, biological control, cultural controls, and chemical applications, but only when absolutely necessary and guided by decision flowcharts. It aims to minimize economic, health, and environmental risks compared to reliance on chemical pesticides alone.

Question 49

What are two major land-use constraints that limit the intensification of agriculture globally?

Answer 49

Two major land-use constraints are the limited availability of new land suitable for agriculture and the widespread degradation of existing agricultural soils due to practices like erosion, salinization, and nutrient depletion.

Question 50

How does the use of fixed quotas for fisheries management pose a risk of stock collapse?

Answer 50

Fixed quotas at the estimated maximum sustainable yield (MSY) are risky because they don't account for natural environmental fluctuations that can reduce population recruitment. If recruitment falls below the fixed quota, the population size will decline, potentially leading to extinction if the quota is maintained.