Chapter 12 and 12.5

Question 1

The last 300 years have seen more extensive change to the Earth’s biomes than in any other period in the earth’s history?
True
False

Answer 1

True

Question 2

1. What is the term used to describe small scale farmers using machetes then set alight an area in an effort to clear the land for farming?______. Seeds are then thrown into the still warm ashes - which are used as basic fertiliser. As soil fertiity declines through continual burning and overuse farmers move into other areas continuing the process - affecting the environment as they go.
2. Which of the available regions in the word bank below would you suggest the technique mentioned above mostly occurs in? _
3. Approximately how many million hectares of Australian land has been cleared for farming or logged since European settlement? _

Answer 2

Slash and burn farming
Sub Saharan Africa
50 million

Question 3

What are the three most important grains we consume daily on a global scale?

Answer 3

Corn
Wheat
Rice

Question 4

1. What percentage of the worlds consumed water is used for agriculture, specifically irrigation?_
2. Fertilisers such as nitrogen, _____ and animal manure may end up in water sources causing _____ to grow out of control.
3. What infrastructure is primarily used to divert or hold water, that can then be used to irrigate regulate rivers._

Answer 4

70%
Phosphorus
Algae
Dams

Question 5

How many times saltier than the sea are parts of the Murray River - especially in South Australia near the mouth of the river at Goolwa._

Answer 5

5 times

Question 6

Identify the following definitions

1. A natural version of salinity that develops in the landscape over time. _
2. Salinity caused by human impact. _

Answer 6

1. Primary salinity

2. Secondary salinity

Question 7

Human impact is related to the irrigation of soil to grow crops. _____ in the irrigation water are left in the soil, and eventually, the soil cannot support plant life. Approximately _________ million hectares of Australian soil is affected and degraded in this way

Answer 7

Salt

2 million

Question 8

The _ security of people who live in the world’s dryland areas in under threat from a process known as _.

How many million people are suggested by the UN to be affected by this lack of security?_

Answer 8

Food
Desertification
250 million

Question 9

The Green Wall of China

1. How many trees are the Chinese Government planning to plant? _
2. Approximately how many km of trees will be planted? _
3. Which desert is in close proximity to the Chinese area under threat from desertification._

Answer 9

1. 1 billion trees
2. 4480km of trees planted
3. The Gobi desert

Question 10

We dont need to do 12

Answer 10

We dont need to do 12