3.2.3: Biodiversity under threat

Question 1

Biodiversity

Answer 1

The number and variety of organisms within an area.

Question 2

What is often used as a measure of health of ecosystems

Answer 2

biodiversity

Question 3

When did biodiversity become a widely used term

Answer 3

1980s

Question 4

Indicators used to measure biodiversity

4

Answer 4

species richness
ecosystem/habitat biodiversity
genetic biodiversity
species evenness

Question 5

Species richness

Answer 5

number of different species

Question 6

Ecosystem/habitat biodiversity

Answer 6

variety of habitats/ecosystems

Question 7

Genetic biodiversity

Answer 7

genetic diversity in a population

Question 8

Species evenness

Answer 8

How evenly distributed species are

Question 9

Why is biodiversity important

4 reasons

Answer 9

• genetic biodiversity can control an ecosystems resistance to pests/diseases
• provides essential goods and services
• has aesthetic and spiritual value
• supports complex interactions between plants and animals

Question 10

Threats to biodiversity

4

Answer 10

human, physical

indirect, direct

Question 11

Direct threats to biodiversity

Answer 11

Mostly regulate land management practices

Question 12

Direct threats to biodiversity
examples
5

Answer 12

industry, agriculture, mining, tourism, urbanisation

Question 13

Indirect threats to biodiversity
and examples
4

Answer 13

• changing temperature and rainfall patterns
• sea level rise
• increased severity of storms and events such as cyclones
• ocean acidification

Question 14

Indirect threats to biodiversity

Answer 14

Mostly associated with human induced climate change

Question 15

Humans have degraded

percentage of land and oceans

Answer 15

75% of land degraded

66% of oceans degraded

Question 16

The living planet index

Answer 16

A measure of the state of global biological diversity based on population trends of vertebrate species from around the world

Question 17

Other biodiversity health indexes

3

Answer 17

red list index
species habitat index
biodiversity intactness index

Question 18

Why are tropical rainforests fragile?

6 reasons

Answer 18

1. High biodiversity
2. Loss of ecological niches effects food webs largely
3. Biomass loss reduces carbon storage
4. Most nutrients stored in biomass store
5. Inputs of organic matter to soil stores reduced by deforestation
6. Loss of a canopy cover results in increased loss of nutrients through leaching and overland flow

Question 19

Threats to tropical rainforests

4

Answer 19

1. climate change
2. acid rain
3. invasive species
4. deforestation

Question 20

Three most at risk ecosystems

Answer 20

tropical rainforests, coral reefs, wetlands

Question 21

ITCZ

Answer 21

inter tropical convergence zone

Question 22

Inter tropical convergence zone

Answer 22

where trade winds meet at the equator

Question 23

Why are coral reefs fragile?

6

Answer 23

1. Increasing temps. of seas, coral lose algae
2. Acidification of oceans, result of CO2 emissions
3. Direct threats from overfishing and tourism
4. Support 25% of marine species even though make up less than 0.1% of the ocean floor
5. vertical growth & complexity provide numerous habitats
6. Support valuable fish stocks

Question 24

Wetland

definition

Answer 24

Flooded area of land that has a distinct ecosystem and vegetation adapted for life in water-saturated soils.

Question 25

Factors which cause variation in wetlands

7

Answer 25

1. Difference in soils
2. Topography
3. Climate
4. Hydrology
5. Water chemistry
6. Vegetation
7. Human disturbance

Question 26

Two types of wetlands

Answer 26

coastal/tidal wetlands

inland/ non-tidal wetlands

Question 27

Distribution of wetlands

Answer 27

found on every continent except Antarctica

Question 28

Freshwater ecosystems occupy …& of the Earth’s surface

Answer 28

less than 1%

Question 29

Wetlands since 1900

Answer 29

Over half the World’s wetlands have gone since 1900

Question 30

Direct threats to wetlands

4

Answer 30

commercial development
drainage
overfishing
extraction of minerals and peat

Question 31

Indirect threat to wetlands

leads to

Answer 31

climate change,
leading to
-swamping of shallow wetlands which submerges and drowns some species
-drought, drying up of others