Human activities that can affect biodiversity and can impact on the magnitude, duration and speed of ecosystem change

Question 1

Habitat destruction, fragmentation or degradation

Answer 1

loss of habitat for animals

Question 2

The introduction of invasive species

Answer 2

An organism that has been released into an ecosystem in which it does not naturally occur.

Question 3

Unsustainable use of natural resources

Answer 3

Overfishing, Overcropping, Overstocking, Overgrazing. Leads to Habitat loss, Erosion Dry land salinity, Loss of biodiversity and Extinction

Question 4

Deforestation

Answer 4

destroying homes and means of food

Question 5

Climate change

Answer 5

With the increased burning of fossil fuels, ruminant flatulence and deforestation, levels of methane and carbon dioxide are increasing. These “greenhouse” gases trap the sun’s IR radiation increasing the world’s temperature which leads to: Climate disturbance, rising sea levels (loss of habitat and arable land) and Loss of biodiversity

Question 6

Global warming

Answer 6

leads to melting of the polar ice caps.
Rising sea levels, higher temperatures.
Failure of crops in some areas
Distribution of wild plants would change.
These changes would affect the distribution of animals that are dependent on the plants
Greater rainfall and intense storms due to changes in climate patterns.
This would affect the distribution of plants and animals.
Life cycles and populations of pest species would alter as they adapt to the changed climate

Question 7

Ozone depletion

Answer 7

increase in CFCS

Question 8

Eutrophication

Answer 8

refers to an excessive amount of nutrients in a body of water, usually caused by runoff of nutrients (mainly phosphorous in freshwater and nitrogen in saltwater) from the land, which causes a dense growth of plant life, leading to a decrease in oxygen supply, which causes the death of animals.

Question 9

Dry land salinity

Answer 9

The accumulation of salt in soil and waterways to levels which are normally toxic to plants and animals. Caused by land clearing – saline groundwater rises to the surface and concentrates. Consequences include Productivity of crops reduced as well as the sustainability of agriculture
In extreme cases water may be to salty for animals and humans to drink.
Buildings and fences roads can be damaged

Question 10

Biomagnification

Answer 10

Biomagnification is a process in which chemical substances become more concentrated at each higher trophic level. Such chemical substances tend to be difficult to be removed from animal and plant tissues.
Leads to: Decreased populations of higher order consumers and Extinction of higher order consumers (DDT interferes with the deposition of calcium in the shells of the bird’s eggs)

Question 11

Bioaccumulation:

Answer 11

the build-up in body tissue of substances that are neither used (metabolised) nor excreted by cells. Many chemicals cannot be broken down and so they accumulate in the soil or in the aquatic environment