Test 2

Question 1

What is the world birth rate?

Answer 1

21

Question 2

What is the world death rate?

Answer 2

9

Question 3

What is the world growth rate?

Answer 3

1.28%

Question 4

What is the replacement fertility rate?

Answer 4

MDC= 2.1
LDC = 2.5

Question 5

What is the total fertility rate (TFR)?

Answer 5

number of children / woman

Question 6

What percentage of the world is in the pre-productive stage?

Answer 6

18% in MDCs

30% in LDCs

Question 7

What percentage does immigration add to the population.

Answer 7

about 1%

Question 8

What percentage of the world has a population rate the is declining?

Answer 8

13% – 38 countries

Question 9

What are the worlds ecological footprints

Answer 9

MDC = 20 acres / person
LDC = 2 acres / person
US 30.2 acres / person

Question 10

What is the available amount of space per person?

Answer 10

4.7 available — 5.7 estimated future use = population crash!

Question 11

mineral percentages in soil?

Answer 11

minerals; 92% silicates (the rest oxides, sulfides, carbonates.

Question 12

What is an igneous rock?

Answer 12

One formed by cooling and crystallization.

Question 13

What is a metamorphic rock?

Answer 13

One formed by heat and pressure.

Question 14

What is a sedimentary rock?

Answer 14

One formed by weathering, erosion, transport, deposit or lithification.

Question 15

what is physical weathering? Where is it most important?

Answer 15

–ice and frost wedging
–unloading
–crystal growth
–root wedging
–wind
Most important in arid areas

Question 16

What is chemical weathering? Where is it most important?

Answer 16

–hydrolysis
–acidification
–oxidation
–biochemical weathering4
Most important in humid areas.

Question 17

What does the rate of weathering depend on?

Answer 17

Climate – tmep. and percipitation

rock type—texture, fractures, composition

Question 18

what is soil composed of?

Answer 18

rocks and minerals; ., organics, water, air, and critters

–marginally renewable resource

Question 19

How long does it take to form one inch of soil?

Answer 19

200-1000 years

Question 20

What is a soil profile?

Answer 20

O,A,E,B,C

Question 21

Important characteristics of topsoil

Answer 21

nutrients, roots, water, decomposers

Question 22

Important soil characteristics

Answer 22

• -texture (grain size)-gravel, sand, silt, clay
• -equal amounts is loam
• -porosity—pore space
• -permeability—connections of pores
• -soil structure or sorting—affects porosity and permeability

Question 23

Contributors of soil erosion

Answer 23

water, wind, humans, gravity

increased by farming and deforestation

Question 24

Harmful effects of soil erosion

Answer 24

• -loss of fertility and ability to hold water
• -pollution by sediment
• -55% of all cropland suffers some amount of erosion
• -more fertilizer needed
• -earth movement (landslides) more likely

Question 25

Degradation of soil

Answer 25

• -desertification—10% drop in production
• -causes: climate, overgrazing, deforestation, bad farming
• -40% of all land shows some desertification

Question 26

irrigation of soil

Answer 26

• -salt buildup from evaporation

- -50% of all cropland shows some salinization

Question 27

waterlogging

Answer 27

wash salt to groundwater

Question 28

ways to conserve soil

Answer 28

• -minimum tillage
• -no tillage
• -terracing
• -contour farming
• -strip cropping
• -agroforestry
• -organic fertilizers

Question 29

Food systems

Answer 29

cropland = 76% of world food
rangeland = 17% (meat and dairy)
oceans = 7%