Land Use

Question 1

How is the ice-free land distributed?

Answer 1

Dester/tundra 18%
Savanna/grass/shrub 40%
Forest 40%

Question 2

How many percentages does human land use affect the ice-free and?

Answer 2

Directly affects more than 50% of the Earth’s ice-free land surface. Some estimates say 75%.

Question 3

What tends to happen to land use over time?

Answer 3

It becomes more invasive

Question 4

What happened to the expansion of agriculture and cropland per person in the late 20th century? Why?

Answer 4

It slowed or halted, declined.

Intensification

Question 5

How much does land use account for of the cumulative CO2 emission?

And what happens as fossil fuel use increases?

Answer 5

25%

the relative contribution of land use declines.

Question 6

How much forest did humanity destroy by expanding agricultural land?

Answer 6

One third 1/3!

Question 7

How much land use did forests cover before agriculture?

Answer 7

almost half of the ice-free land surface.

Question 8

Primary or frontier forests?

Answer 8

Forests that have never been cut down

Question 9

secondary forests?

Answer 9

Forests that have regrown after being cut

Question 10

Side effect of replaning forest?

Answer 10

These are often monocultures of introduced species from other parts of the world. They have lower biodiversity than natural forests but are effective at carbon storage.

Question 11

What is the leading cause of deforestation in all areas?

Answer 11

Agriculture

Question 12

What areas have the higest rate of deforestation? Why?

Answer 12

Congo:
small-scale subsistence farming.
Deforestation is driven by rapid population growth and lack of alternative livelihoods.

Indonesia:
cleared for oil palm plantations. Large-scale agriculture driven by rapid economic growth is the leading cause of deforestation in this region.

Question 13

What is the leading cause of leading cause of habitat loss and degradation and what does it lead to?

Answer 13

Forest fragmentation and destruction, leading threat to terrestrial biodiversity.

Question 14

What are the two ways deforestation releases CO2?

Answer 14

• It reduces the
amount of CO2 that is being taken up through photosynthesis.

• It increases decomposition of organic matter in dead vegetation and disturbed soil.

Question 15

Where is most of the carbon in the biosphere forest, superficially tropical forests?

Answer 15

Most of this carbon is stored in forests.

Tropical forest = 25%

Question 16

What did grasses evlove with?

Answer 16

Large herbivores

Question 17

What maintains plant diversity in grasslands?

Answer 17

Moderate grazing.

Question 18

What does extreme overgrazing in arid areas led to?

Answer 18

desertification

• Loss of soil structure and vegetation

Question 19

How many live in cites?

Answer 19

55% of the global population, about 4.3 billion people

Question 20

Where are all future population growth is projected to occur?

Answer 20

Urban areas.

Question 21

What is growing faster urban area or urban population? + how much % does it cover? + what will it replace

Answer 21

Urban ara over 0.75% of Earth’s ice-free land surface.

urban expansion will replace cropland.

Question 22

Why does heat emanates from urban areas? re-radiate and radiate

Answer 22

Pavement and other surfaces in cities absorb sunlight and re-radiate heat at night.

Cars, buildings, industry, and people radiate hear.