Topic 3

Question 1

species diversity

Answer 1

species diversity in communities is a product of two variables, the number of species (richness) and their relative proportions (evenness)

Question 2

genetic diversity

Answer 2

is the range of genetic material present in a gene or pool population of a species

Question 3

habitat diversity

Answer 3

is the range of different habitats per unit area in a particular ecosystem or biome

Question 4

a habitat with high biodiversity has these advantages

Answer 4

• resilience and stability
• genetic diversity so resilient to diseases
• some plants will have deep roots and so can cycle nutrients and bring them to the surface making them available for other plants

Question 5

high biodiversity does not always equate to having a healthy ecosystem

Answer 5

diversity could be the result of fragmentation (break up) of a habitat
managing grazing can be difficult as plant species have different requierments and tolerance to grazing
some stable and healthy communities have few plant species, so are an exception to the rule

Question 6

biodiversity hotspot

Answer 6

is a region with a high level of biodiversity that is under threat from human activities

Question 7

natural selection

Answer 7

mechanism by which individuals that are better suited to their environment survive and reproduce more successfully. ‘survival of the fittest’ It is the mechanism of evolution

Question 8

variation

Answer 8

each individual in a species is different due to it’s specific set of inherited genes
causes - genetic mutation

Question 9

speciation

Answer 9

is the formation of new species when populations of a species become isolated and evolve differently

Question 10

components of natural selection

Answer 10

• competition - survival

- reproduction

Question 11

mechanism of natural selection

Answer 11

• variation in the population
• some individuals are more fit than others and they reproduce more than other individuals
• the offspring of the fitter individuals may inherit the genes that then provide them with an advantage to survive the environment
• this gradual genetic change in a population leads to favourable characteristics accumulating over team
• taken together, this leads to evolution ( a new species arising over time

Question 12

physical barriers result in splitting the gene pool;

Answer 12

• splitting of godwana - australia split off

Question 13

land bridges allow species to invade new areas

Answer 13

may result from lowering of seawater levels

Question 14

continental drift, continents have moved to different climatic zones

Answer 14

has resulted in new and diverse habitats

Question 15

constructive

Answer 15

move apart, may create new land

Question 16

conservative plate boundary

Answer 16

slide past each other

Question 17

destructive

Answer 17

crust is subducted beneath the other crust

Question 18

convergent plates

Answer 18

collude and form mountains

Question 19

past mass extinctions caused by ohysical factors

Answer 19

• volcanic eruption

meteor impact

Question 20

factors that help maintain biodiversity

Answer 20

• complexity of the ecosystem; more complex more resilient
• stage of succession; later more resilient
• limiting factors; abundance of limiting factors means more resilient
• inertia; property of an ecosystem to resist change when subjected to a disruptive force

Question 21

natural hazards

Answer 21

are naturally occuring events that may have a negative impact on the environment (and humans)

Question 22

factors that lead to a loss of biodiversity
(HIPPO)
Habitat destruction and fragmentation
Introduced species
Pollution
Practices of agriculture
Over hunting

Answer 22

• natural hazards, e.g. volcanic eruptions, wildfires
• fragmentation of habitat; a large area is divided into patchwork of fragments, separated by towns, roads, etc.
• pollution; local - pesticides, environmental - emissions from factories, run-off fertilisers
• overexploitation
• introducing non-native/ alien species
• spread of disease
• modern agricultural practices

Question 23

vulnerability of tropical rainforests

Answer 23

background;
- contain over 50% of all species of plants and animals on earth
- but only covers 6% of the land area on earth
vulnerable to disturbance;
most species have specialised niches
deforestation; timber, land for cattle to provide beef, soya and biofuels 9e.g. palm oil in Southeast Asia)
changing one part of ecosystem alters the entire web of relationships
tropical rainforests are found on nutrient-poor soils that are thin and easily eroded once forest is cleared.
small- scale disturbance - 50 years
large areas of cleared land - 4000 years if at all

Question 24

what makes a species prone to extinction

Answer 24

narrow geographical range
small population size
low population densities and large territories
few populations of the species
a large body (90% energy lost to the environment - top predators are rare)
low reproductive potential
seasonal migrants
poor dispersers
specialized feeders
edible to humans and herding together
island organisms

Question 25

The IUCN red list

Answer 25

The International Union for the Conservation of Nature and Natural resources - is an international agency
The red lists of threatened species are objective lists of species under varying levels of threat to their survival. Criteria are: 
Extinct 
extinct in the wild
Critically endangered
endangered
vulnerable
near threatened
least concern
data deficient
not evaluated

Question 26

the dodo

Answer 26

large flightless bird endemic to the island of Mauritius
no major predators, the dodo had no need of flight, it was a ground-nesting bird
Portuguese sailors discovered the island and ate the dodo. later it was used as a jail and rats, pigs, and monkeys where introduced. these ate dodo eggs and humans killed the dodo for sport and food. conversion of forest plantations also destroyed their habitat and it was extinct by 1681
island fauna impoverished by the loss of the dodo

Question 27

endangeredd species - siberian tiger

Answer 27

top carnivore
forests across Asia destroyed for timber or for the conversion of agriculture. Caused direct death of tigers and population fragmentation. Causes repeated breeding with the same gene pool, weakening tigers as they are born with defects and mutations.
Habitat destruction caused primarily by uncontrolled LEDCs.
Poaching - boned tiger worth 50 000-100 000 US $.
The WWF work towards conservation. Strengthening international treaties, supporting surveys, pushing for the enforcement of laws controlling illegal trade of tiger parts.
They are under CITES.

Question 28

value of biodiversity (into 3 E\vPs)

Answer 28

ecocentric; intrinsic value (right to exist), ethical
anthropocentric;
food source
natural products; fertilizer, pesticides, rubber, honey
medicine
economic/commercial value - fibres - can be used for clothing
scientific and educational value
ecotourism
aesthetic value
future potential uses

Question 29

conservation biology

Answer 29

is the sustainable use and managment of natural resources

Question 30

preservation biology

Answer 30

attempts to exclude human activity in areas where humans have not yet encroached

Question 31

IGOs

Answer 31

intergovernmental organisations

e,g, Un, IPCC

Question 32

GOs

Answer 32

Governmental organisations
part of and funded by a national government
highly bureaucratic
e.g. Environmental Protection Agency (EPA) - USA

Question 33

NGOs

Answer 33

Non-governmental organisations
not a part of government
not for profit
may be international or local
some run by volunteers
very diverse
e.g. Friends of the Earth, Greenpeace

Question 34

IGOS vs NGOS

Answer 34

Speed of response; NGO- rapid, can make their own decisions vs IGOS slow must be agreement between governments
use of media; NGO - use film of activities to gain media attention, professional medial liaison officers prepare and read written statements
Diplomatic constraints; NGOs unaffected, IGOS - many constraints, need agreement from all parties
enforceability; NGOs - no direct power, must use public opinion to persuade governments to act IGOS - use international treaties and national laws to protect the environment, ecosystems and biodiversity

Question 35

International Conventions on Biodiversity

Rio Earth Summit 1992

Answer 35

Attended by 172 governments
implementation of Agenda 21
conservation of biological variation
sustainable use of its components and; 
the equitable sharing of the benefits arising out of the utilization of genetic resources

Question 36

approaches to conservation; species based conservation

Answer 36

CITES - stop species becoming endangered because of international trade
Captive breeding and zoos - but hard to reintroduce a species into the wild
Botanical gardens and seed banks; way of preserving genetic variation of a species
Flagship species; charismatic not much ecological value e.g. Panda - appeal to public, funds can be used for habitat that helps all species there. But; they take priority, if extinct - failure
Keystone species - bigger effect on the environment

Question 37

keystone species

Answer 37

a keystone species is one that plays a critical role in maintaining the structure of the ecosystem in which they live

Question 38

habitat conservation

Answer 38

designing protected areas;
location?
size and shape of parks and reserves?
corridors strips of protected land can link reserves, increasing the gene pool or allowing seasonal migration
Buffer zones - help protect conservation areas and maintain equilibrium and biodiversity