Habitat Destruction, Fragmentation, Degradation

Question 1

What are the three ways humans dominate the global ecosystem?

Answer 1

• land surface
• nitrogen cycle
• atmospheric carbon cycle

Question 2

How have humans dominated land surface?

Answer 2

human land use of resources, mainly agriculture and forestry, have transformed as much as half of the Earth’s ice-free land surface

Question 3

How have humans dominated the nitrogen cycle?

Answer 3

each year human activities, such as cultivating nitrogen-fixing crops, using nitrogen fertilizers, and burning fossil fuels, release more nitrogen into terrestrial systems than is added by natural processes

Question 4

How have humans dominated the atmospheric carbon cycle?

Answer 4

by the middle of this century, human use of fossil fuels and cutting down forests will have resulted in a doubling of the level of carbon dioxide in the Earth’s atmosphere

Question 5

What is major cause of deforestation in rainforest?

Answer 5

• slash and burn
• cattle ranching

Question 6

What are consequences of deforestation?

Answer 6

• loss of biodiversity
• increase in CO2 leading to increased temperatures
• erosion and increased vulnerability to fire

Question 7

Where are two places deforestation has severely occured?

Answer 7

Amazon rainforest and Madagascar

Question 8

What is slash and burn?

Answer 8

trees/vegetation cut down and burned for agriculture

Question 9

What do nitrogen-fixing bacteria in legume nodules do?

Answer 9

take nitrogen gas (N2) and convert it into a form that most living beings can uptake

Question 10

Why do we need nitrogen?

Answer 10

amino acids, proteins, DNA