Chapter 12 and 12.5 Flashcards
(10 cards)
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
True
- 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.
- Which of the available regions in the word bank below would you suggest the technique mentioned above mostly occurs in? _
- Approximately how many million hectares of Australian land has been cleared for farming or logged since European settlement? _
Slash and burn farming
Sub Saharan Africa
50 million
What are the three most important grains we consume daily on a global scale?
Corn
Wheat
Rice
- What percentage of the worlds consumed water is used for agriculture, specifically irrigation?_
- Fertilisers such as nitrogen, _____ and animal manure may end up in water sources causing _____ to grow out of control.
- What infrastructure is primarily used to divert or hold water, that can then be used to irrigate regulate rivers._
70%
Phosphorus
Algae
Dams
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._
5 times
Identify the following definitions
- A natural version of salinity that develops in the landscape over time. _
- Salinity caused by human impact. _
- Primary salinity
2. Secondary salinity
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
Salt
2 million
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?_
Food
Desertification
250 million
The Green Wall of China
- How many trees are the Chinese Government planning to plant? _
- Approximately how many km of trees will be planted? _
- Which desert is in close proximity to the Chinese area under threat from desertification._
- 1 billion trees
- 4480km of trees planted
- The Gobi desert
We dont need to do 12
We dont need to do 12
