6.7 biological carbon cycles and water cycle threatened by human activity

Question 1

Increased demand for food has caused deforestation due to increased production of…

Answer 1

• Soy
• Palm oil
• Beef (cattle ranching)

Question 2

Increased demand for fuel has caused deforestation due to increased production of…

Answer 2

• Oil and tar sands production (Russia, Canada)
• Sugar cane production (for ethanol)
• Coal mining

Question 3

Land cover data

Answer 3

How much of an area is covered by forests, wetlands, impervious surfaces, agriculture, and other land and water types. It can be assessed/identified using imagery from satellites such as Landsat.

Question 4

Deforestation

Answer 4

Removal of forest through logging, clear cutting and slash and burn techniques.

Question 5

Reforestation

Answer 5

Planting trees in areas with recent tree cover, replacing lost primary forests.

Question 6

Primary Forest

Answer 6

Forests where there are no clear indications of human activities and the ecological processes (e.g. succession) are not significantly disturbed.

Question 7

Secondary Forest

Answer 7

A regenerated forest that has been previously cleared by natural or man made causes.

Question 8

Afforestation

Answer 8

Planting trees is an area that has never had forest, or has been without forest for a long time.

Question 9

Land conversion

Answer 9

Any change from a natural ecosystem to an alternative use; it usually reduces carbon and water stores and soil health.

Question 10

Terrestrial carbon stores

Answer 10

Carbon that is sequestered and stored by land-based biological or physical/geological processes.

Question 11

Soil health

Answer 11

The continued capacity of soil to function as a vital living ecosystem that sustains plants, animals, and humans. Healthy soil also helps to regulate water flow, the cycling of nutrients and providing larger plants/root systems with physical stability and support.

Question 12

Ocean acidification

Answer 12

A decrease in the pH of the Earth’s oceans caused by the uptake of carbon dioxide from the atmosphere.

Question 13

pH

Answer 13

A logarithmic measure of acidity or alkalinity. A value of 7 is neutral; above this is alkaline, below this it is more acidic.

Question 14

Carbon Sink

Answer 14

A natural (or artificial) reservoir that accumulates and stores some carbon-containing chemical compound. The process by which carbon sinks remove carbon dioxide (CO2) from the atmosphere is known as carbon sequestration.

Question 15

Critical Threshold

Answer 15

An abrupt change in an ecological state. Small environmental changes can trigger significant responses. Negative and positive feedback loops reinforce or undermine changes once an alternative stable state has become established.

Question 16

Ecosystem Resilience

Answer 16

The level of disturbance that ecosystems can cope with while keeping their original state.

Question 17

Ecosystem services

Answer 17

The way in which humans benefit from the resources/functions found in the natural environment. This can include supporting functions (e.g. nutrient cycling), provision of goods (e.g. food, water, fuel), regulation of Earth’s systems (e.g. GHE, Earth’s ‘green lungs’), cultural value (aesthetic, spiritual, educational, recreational).

Question 18

Nutrient cycling

Answer 18

The movement/exchange of organic and inorganic matter back into the production of living matter. The process is regulated by food web pathways that decompose matter into mineral nutrients.

Question 19

Soil formation

Answer 19

Also known as ‘‘pedogenesis’’. The process begins with weathered rock material, or ‘parent material’, and also involves organic matter (humus).

Question 20

Livestock fodder

Answer 20

Any agricultural foodstuff used specifically to feed domesticated livestock (e.g. cattle, goats, etc).

Question 21

Fuel wood

Answer 21

A fuel, such as firewood, charcoal, chips, sheets, pellets, and sawdust.