Unit 5: Land and Water Use

Question 1

The tragedy of the commons suggests that

Answer 1

individuals will use shared resources in their own self interest rather than in keeping with the common good, thereby depleting the
resource.

Question 2

Clearcutting can be economically advantageous but leads

Answer 2

to soil erosion, increased soil

and water temperatures, and flooding.

Question 3

Forests contain trees that absorb

Answer 3

pollutants and store carbon dioxide.

Question 4

The cutting and burning of trees releases

Answer 4

carbon dioxide and contributes to climate change.

Question 5

The Green Revolution started a shift to new

Answer 5

agricultural strategies and practices in order

to produce food production, with both positive and negative results.

Question 6

Some of these strategies and methods are

Answer 6

mechanization, genetically modified organisms, fertilization,
irrigation, and the use of pesticides.

Question 7

Mechanization of farming can increase

Answer 7

profits and efficiency for farms and reliance on fossil fuels.

Question 8

Agricultural practices that can cause environmental damage include

Answer 8

tilling, slash and burn farming, and the use of fertilizers.

Question 9

The largest human use of freshwater is for

Answer 9

irrigation (70%)

Question 10

Types of irrigation include

Answer 10

drip irrigation, flood irrigation, furrow irrigation, and spray irrigation.

Question 11

Waterlogging occurs when

Answer 11

too much water is left to sit in the soil, which raises the water
table of groundwater and inhibits plants’ ability to absorb oxygen through their roots.

Question 12

Furrow irrigation involves

Answer 12

cutting furrows between crop rows and filling them with water.
This system is inexpensive but about ⅓ of the water is lost to evaporation and runoff.

Question 13

Flood irrigation involves

Answer 13

flooding an agricultural field with water. This system sees about
20% of the water lost to evaporation and runoff. This can also lead to waterlogging

Question 14

Spray irrigation involves

Answer 14

pumping groundwater into spray nozzles across an agricultural
field. This system is more efficient than flood and furrow, with only ¼ or less of the water
lost to evaporation or runoff. However, spray systems are more expensive than flood
and furrow irrigation, and also require energy to run.

Question 15

Drip irrigation uses

Answer 15

perforated hoses to release small amounts of water to plant roots.
This system is the most efficient, with only about 5% of the water lost to evaporation and
runoff. However, this system is expensive and so is not often used.

Question 16

Salinization occurs when

Answer 16

the salts in groundwater remain in the soil after the water

evaporates. Over time, salinization can make soil toxic to plants.

Question 17

Aquifers can be severely depleted if

Answer 17

overused for agricultural purposes, as has

happened to the Ogallala Aquifer in the central United States.

Question 18

One consequence of using common pest control methods such as pesticides, herbicides, fungicides, rodenticides, and insecticides is that

Answer 18

organisms can become resistant to them through artificial selection. Pest control decreases crop damage by pests and increases crop yields.

Question 19

Crops can be genetically engineered to increase their

Answer 19

resistance to pests and disease.
However, using genetically modified crops in planting or other ways can lead to loss of
genetic diversity of that particular crop.

Question 20

Methods of meat production include

Answer 20

concentrated animal feeding operations (CAFOs),

also called feedlots, and free range grazing.

Question 21

Meat production is less efficient than

Answer 21

agriculture; it takes approximately 20 times more

land to produce the same amount of calories from meat as from plants.

Question 22

CAFOs are used as a way to

Answer 22

quickly get livestock ready for slaughter. They tend to be
crowded, and animals are fed grains or feed that are not as suitable as grass.
Additionally, feedlots generate a large amount of organic waste, which can contaminate
ground and surface water.The use of feedlots are less expensive than other methods,
which can keep costs to consumers down.

Question 23

Free range grazing allows animals to

Answer 23

graze on grass during their entire lifecycle. Meat
from free range animals tends to be free from antibiotics and other chemicals used in
feedlots. Organic waste from these animals acts as fertilizer. Free range grazing
requires large areas of land and the meat produced is more expensive for consumers.

Question 24

Overgrazing can cause

Answer 24

desertification. Desertification is the degradation of low

precipitation regions toward being increasingly arid until they become deserts.

Question 25

Less consumption of meat could

Answer 25

reduce CO 2 , CH 4 , and N 2 O emissions, conserve water,

reduce the use of antibiotics and growth hormones, and improve topsoil.

Question 26

Overfishing has led to the extreme

Answer 26

scarcity of some fish species, which can lessen
biodiversity in aquatic systems and harm people who depend on fishing for food and
commerce.

Question 27

As the more accessible ores are mined to depletion,

Answer 27

mining operations are forced to
access lower grade ores. Accessing these ores requires increased use of resources that
can cause increased waste and pollution.

Question 28

Surface mining is the

Answer 28

removal of large portions of soil and rock, called overburden, in
order to access the ore underneath. An example is strip mining, which removes the
vegetation from an area, making the area more susceptible to erosion.

Question 29

Mining waste includes

Answer 29

the soil and rocks that are moved to gain access to the ore, and
the waste, called slag and tailings, remain when the minerals have been removed from
the ore. Mining helps provide low cost energy and material necessary to make products.
The mining of coal can destroy habitats, contaminate groundwater, and release dust
particles and methane.

Question 30

As coal reserves get smaller, due to lack of easily accessible reserves, it becomes necessary to

Answer 30

access coal through subsurface mining, which is very expensive.

Question 31

Urbanization can lead to depletion of

Answer 31

resources and saltwater intrusion in the water cycle

Question 32

Urbanization, through the burning of fossil fuels and landfills, affects the carbon cycle by

Answer 32

increasing the amount of carbon dioxide in the atmosphere.

Question 33

Impervious surfaces are

Answer 33

human made structures such as roads, buildings, sidewalks,

and parking lots that do not allow water to reach the soil, leading to flooding.

Question 34

Urban sprawl is the change

Answer 34

in population distribution from high population density areas
to low density suburbs that spread into rural areas, leading to potential environmental
problems.

Question 35

Ecological footprints compare

Answer 35

resource demands and waste production required for an

individual or a society.

Question 36

Sustainability refers to

Answer 36

humans living on Earth and their use of resources without depletion of the resources for future generations. Environmental indicators that can guide humans to sustainability include biological diversity, food production, average global surface temperatures and CO 2 concentrations, human population and resource depletion.

Question 37

Sustainable yield is the

Answer 37

amount of a renewable resource that can be taken without

reducing available supply.

Question 38

Methods to increase water infiltration include

Answer 38

replacing traditional pavement with

permeable pavement, planting trees, increased use of public transportation, and building up, not out.

Question 39

Integrated Pest Management (IPM) is

Answer 39

a combination of methods used to effectively
control pest species while minimizing the disruption to the environment. These methods
include biological, physical, and limited chemical methods such as biocontrol,
intercropping, crop rotation, and natural predators of the pests.

Question 40

The use of IPM reduces

Answer 40

the risk that pesticides pose to wildlife, water supplies, and human health.

Question 41

IPM minimizes

Answer 41

disruptions to the environment and threats to human health but can be complex and expensive.

Question 42

The goal of soil conservation is to

Answer 42

prevent soil erosion. Different methods of soil conservation include contour plowing, windbreaks, perennial crops, terracing, no till agriculture, and strip cropping.

Question 43

Rotational grazing is the

Answer 43

regular rotation of livestock between different pastures in order to avoid overgrazing in a particular area.

Question 44

Aquaculture has expanded because

Answer 44

it is highly efficient, requires only small areas of water, and requires little fuel.

Question 45

Aquaculture can contaminate

Answer 45

wastewater, and fish that escape can compete or breed
with wild fish. The density of fish in aquaculture can lead to increases in disease
incidences, which can be transmitted to wild species.

Question 46

Some of the methods for mitigating deforestation include

Answer 46

reforestation, using and buying

wood harvested by ecologically sustainable forestry techniques, and reusing wood.

Question 47

Methods to protect forests from pathogens and insects include

Answer 47

IPM and the removal of

affected trees.

Question 48

Prescribed burn is a method by which

Answer 48

forests are set on fire under controlled conditions

in order to reduce the occurrence of natural fires.