Summarising Biodiversity Under Threat

Question 1

Genetic diversity definition

Answer 1

The range of genes found within a particular species.

Question 2

Ecosystem diversity definition

Answer 2

The range of different ecosystems, habitats and niches within an area.

Question 3

Species diversity

Answer 3

The number of different plant and animals species in an area.

Question 4

What factors influence biodiversity?

Answer 4

Productivity 
Disturbance 
Succession
Isolation 
Dispersal and colonisation 
History and age 
Indirect human drivers of change

Question 5

Summary of some influences on Biodiversity

Answer 5

Biodiversity is high on large, mountainous, tropical (low latitude) islands- Madagascar, Sumatra and java are good examples.
Lack of factors to limit growth: lots of light, warmth and rain promotes growth.
Altitude produces a range of ecological zones, each with its own species- good news for coping with climate change
Isolation and endemism
Large areas can support large numbers of species- complex food chains.
Decay and nutrient cycling are rapid nutrient soils
Limits human influence

Question 6

Biodiversity hotspot

Answer 6

Areas with high species richness, endemism and severe human threats
Pivotal areas- are those with concentrations of hotspots

Question 7

Over-Harvesting

Answer 7

Due to human over-hunting, megafauna (large mammals) has become increasingly more extinct in most continents, apart from Africa.
When humans take resources from the environment at a faster rate than they are being produced naturally.
They’re more humans- technology improving, we often take too much e.g. deforestation, over fishing.

Question 8

Invasive/ Introduced Species

Answer 8

Hawaii- mostly introduced species.

Cannibal snails- Hawaii

Question 9

Habitat Change/ Destruction

Answer 9

Humans: urbanisation, farmland- deforestation to make way for cities.
Large knock-on effect on food chains and biodiversity.
If you are in an area with altitudinal zoning, survival is more likely as you do not have to move as far to find suitable climate.

Question 10

Islandisation/ Fragmentation

Answer 10

Islands of undisturbed habitat in a sea of totally disturbed habitat
Might not be enough space to provide food for all the species.
Edges that are vulnerable and interaction with human interference.
Fragment = smaller population = greater vulnerability to…e.g disease, human interaction (easier to wipe out)
Smaller fragments, so smaller gene pool makes inbreeding more likely.

Question 11

Pollution

Answer 11

Some pollution is localised e.g water pollution (oil spills, factory waste discharge)
Some pollution is regional or even GLOBAL :O e.g air pollution (smog, acid rain)
Enhanced greenhouse effect
Climate change puts stress on ecosystems e.g. sea level rise
Climate change allows species to move, however, it’s difficult for them due to urbanisation (humans in the way)
Rate of change is unprecedented- harder for moving away

Question 12

In what ways are ecosystems valuable?

Answer 12

Provisioning services/ goods- products derived such as timber, fruits etc.
Regulating services- vital to the functioning of the Earth’s systems e.g carbon sink forests and coral reefs.
Cultural services- aesthetic and spiritual enjoyment, opportunities for recreation.
Supporting services- nutrient cycling, provision of wildlife habitats.

Question 13

The value of coral reefs

Answer 13

Biodiversity- 1% of the entire marine environment but home to 25% of all marine life.
Tourist magnets- more than 100 of the 109 countries with reefs have established tourist industries.
Food
Medicine
Gas exchange
Science and research
Environmental change indicator
Decorative objects
Exotic fish trait- aquarium trade
Shoreline protection- natural coastal protection
Building materials

Question 14

What is eutrophication?

Answer 14

“Excessive richness of nutrients in a lake or other body of water, frequently due to run-off from the land, which causes a dense growth of plant life.”

Question 15

What are the problems with eutrophication?

Answer 15

Algal blooms in rivers and lakes.
Prevents sunlight reaching other water plants, which then die.
Bacteria break down the dead plants and use up the oxygen in the water so the lake may be left completely lifeless.
It causes the water to because anoxic (depleted of oxygen) or hypoxic (low in oxygen).
Eutrophication results in the death of many fish and other aerobic aquatic species.

Question 16

How can eutrophication be avoided/reduced?

Answer 16

Using mimimal required amounts of chemical fertilizers or use natural ones instead.
Be sure not to have the fields close to the water bodies.
Take extra care while using fertilizers during monsoons as due to run-off, they get transmitted to the water bodies.

Question 17

What is an ecosystem?

Answer 17

The arrangement of plant and animals in a particular location and their interaction with each other and their nonliving environment.

Question 18

How does energy flow within an ecosystem?

Answer 18

Sun -> Producers -> Primary consumers (herbivores) -> Secondary consumers (carnivores) -> Tertiary consumers

Question 19

Alien invasive species

Answer 19

Our globalised world increased the threat from alien invasive species
These are species which move out of their natural habitat and colonise new areas, as a result of human activity.
May be introduced deliberately or accidentally.

Question 20

What makes a successful invader?

Answer 20

Short lifespan- able to go through natural selection and become adapted to area quicker if change occurred.
Quick reproduction
Tolerant to lots of food sources

Question 21

Invasive Species and the Galapagos Islands

Answer 21

Rats are bad!
Harbour disease
Reproduce quickly
Eat a lot

Question 22

Sustainable yield

Answer 22

Sustainable yield is the ‘safe’ level of harvest that can be utilised from an ecosystem without harming the environment.
It is a key part of the sustainable management of ecosystems.

Question 23

What players are involved in biodiversity management?

Answer 23

Managing biodiversity involves work from several players. They can operate at a range of scales. Many local players are more involved because they depend on biodiversity for their well being.
Example: Fishermen, farmers

Question 24

Case study: Flynbos, South Africa

Answer 24

Flynbos is the major vegetation type of the small botanical region in South Africa known as the Cape floral kingdom.
Only 5 other floral kingdoms are recognised and it is both the smallest and richest, with the highest known conc of plant species, 1300 per 10 km2.

Question 25

Case study: Flynbos, South Africa- What are the threats?

Answer 25

 Spread of alien plants
 Commercial forestry using non-native species e.g. European pines
 Frequent bush fires
 Construction of housing estates around Cape Town
 Increased farming

Question 26

There are various ways of measuring threatened ecosystems:

Answer 26

1) Economic Scorecard shows the ability of ecosystems to produce goods and services
2) The Living Planet Index monitors changes over time in the populations of representative animal
species in various ecosystems
3) Ecological footprint measures the human impact on the planet
4) Red List of endangered species shows species at risk of extinction
5) Millennium Ecosystem Assessment is a multi-scale assessment by the UN

Question 27

Factors threatening biodiversity: global factors

Answer 27

Climate Change – expected that the climate will change so quickly that species will be unable to
adapt.
Deforestation – clearance of forest cover results in loss of biodiversity and resources but also
has knock-on effects on the food web and nutrient cycling
Pollution can cause various issues:
- Ozone depletion due to CFCs
- nitrate pollution of lakes
Human population growth – this is forcing people to spread into more areas and is encroaching
onto areas with high biodiversity

Question 28

Factors threatening biodiversity: local factors

Answer 28

Fire – was used widely in Europe and N. America to clear forests for development. Controlled fire as a management option is useful but large-scale burning for soya bean production causes loss of biodiversity
Habitat change – developing natural habitats for agriculture, minerals or urban growth e.g. overfishing in the North Sea
Recreational use – plants are vulnerable to trampling and animals to disturbance

Question 29

The impact of these threats on ecosystem processes

Answer 29

Energy Flow- Human action on one level of the chain has an impact on the others that are dependent on it e.g. the catching of tertiary consumers.
Nutrient cycling- People can impact upon the cycle by adding nutrients via fertilisers, by reducing the biomass through overharvesting and deforestation, and by degrading the soil.
Movement of species- see another card

Question 30

Named Example: Udzungwa Mountains National Park: a pristine

area

Answer 30

This national park has huge amounts of biodiversity with 276 tree species and 50 endemic species.
The local villages are also reliant upon it for watershed protection, medicines and food.
However their access is limited and highly controlled due to increasing pressures on the park such as population growth.
The Tanzanian National Park authorities therefore decided to involve the local people in sustainable bottom up strategies for example, setting up tree nurseries and promoting ecotourism.
This was the best way forward due to the issues of policing a vast area with a skeletal ranger force; instead the local people become responsible for the area.

Question 31

Named Example: Masai Mara game reserve: a degraded area

Answer 31

This reserve experienced a breakdown in management which has led to the decline to the grassland ecosystem. The park fees from tourists were meant to go towards management of the area and providing social services to the local tribesman.
However the park rangers were not paid properly and lacked basic equipment so could do little to stop illegal hunting.
In 2008 a private organisation called Mara conservation took over control and runs on a non-profit basis uses 50% of revenue to build roads and anti-poaching patrols and 50% to the local tribes. This is needed as the local people have to give up cattle grazing land for
tourism but are having a hard time seeing the benefits.

Question 32

Named Example: Campfire Project, Zimbabwe

Answer 32

This was developed in the late 1980s aimed to long-term development, management and sustainable use of natural resources.
The responsibility for the area was placed in the hands of local people and therefore an example of a bottom-up approach.
Some schemes made money from big-game hunting at sustainable yield levels and this was then fed back into the communities.
Environmentalists disagreed with this approach as how was hunting endangered species helping to protect them?
The scheme was then undermined by the economic collapse of Zimbabwe and lack of funding.

Question 33

The role of different players in managing biodiversity: global

Answer 33

a) Ramsar Convention 1971 - to conserve wetlands
b) World Heritage Convention 1972 - protect outstanding
cultural and natural sites

Question 34

The role of different players in managing biodiversity: national

Answer 34

Governments:
Regulation – establish and enforce laws to conserve and
protect various areas and species.
Preservation – preserve areas of high biodiversity.

Question 35

Spectrum of strategies and policies for managing biodiversity

Answer 35

Total protection
Biosphere reserves
Restoration
Conservation

Question 36

Named Example: The Galapagos Islands Zoning Strategy (Hot-Spot Management Strategy)

Answer 36

Nearly one fourth of the Galapagos marine life is endemic - found nowhere else on earth.
Threats facing the islands:
- Extensive migration from mainland Ecuador
- Absence of a quarantine system to avoid the introduction of foreign species
- Illegal fisheries threaten the islands’ marine resources
- Lack of an adequate legal framework to ensure the long-term preservation of the islands
- Tourism- In 1998 - $75 million was generated through tourism. However out of this only around 1% is used to support conservation.

1936: the Galapagos National Park (GNP) established
1968: Boundaries finally established; effective park administration began
1992: Zoning plan for Marine Resources reserve

Question 37

Case Study: Named Global Ecosystem- Daintree Tropical Rainforest

Answer 37

Location: North east coast of Australia in Queensland
Why is Daintree so special?
- World Heritage site measuring ½ the size of Wales
- 135 million years old
- Greatest number of threatened species of plant and animals in the world
- ½ of Australia’s bird species
- 65% of all butterfly and bat species

Threats

1) Tourism - 2002- 436000 visitors
2) Destruction of ecosystem to cope with demand
- tarmacking of roads has lead to small areas of forest being divided into plots for sale
- Occupied plots are often bulldozed and turned into cattle ranches
3) Development - development of Port Douglas
4) Climate Change
5) Logging – carbon sink gone

Question 38

Accidental introductions include:

Answer 38

1) Alien species can arrive by ship e.g. Zebra mussel arrived in North America from the CaspianSea by clinging on the sides of ships. These were brought into the Great Lakes where the multiplied to 70,000 per km2
2) Air transport was responsible for introducing snakes to the Pacific Island of Guam which had
huge impacts on the food web

Question 39

Deliberate introductions include:

Answer 39

1) Game species such as pheasant and rainbow trout for hunting
2) Hedgehog was imported from the Scottish mainland to the Outer Hebrides to deal with a plague of garden slugs but have since effected the populations of ground nesting birds whom they eat the eggs of