Human Impact on Environment

Question 1

define extinction

Answer 1

complete loss of species

Question 2

reasons why species become extinct

Answer 2

natural selection
non contingious population
loss of habitat
deforestation
loss of hedgerows
drainage of wetlands
over hunting by humans
competition- interspecific (alien species)
pollution

Question 3

define conservation

Answer 3

is the planned management of ecosystems to
enhance biodiversity and protect gene pools.

Question 4

how can conservation be achieved

Answer 4

 Protecting habitats e.g. SSSIs and Nature Reserves
 International co-operation restricting trade in endangered species and their parts
e.g. ivory and the products of whaling (look at the CITES web site)
 Gene & Sperm banks
 Seed banks (Kew Gardens)
 Rare breed societies
 Species reintroduction e.g. the red kite in mid-Wales
 International organisations which organise publicity to educate and increase public
awareness e.g. WWFN
 Legislation e.g. the EU Habitats Directive
 Ecotourism, which aims to educate, conserve and contribute to local economies

Question 5

what is a monoculture

Answer 5

is the growth of large numbers of
genetically identical crop plants in a defined area.

Question 6

disadvantage of monoculture

Answer 6

provide only one type of habitat- which reduces biodiversity

Question 7

advantage monoculture

Answer 7

Monocultures reduce soil fertility as roots grow to the same length and extract minerals from the same depth – this increases the need for
chemical fertilisers.

Question 8

how is pesticide used by farmers

Answer 8

Plants of the same species, grown so close together,
are also susceptible to the same pests and diseases,
which are able to pass from plant to plant rapidly.

Question 9

define pesticide

Answer 9

include chemicals which kill or inhibit the
growth of weeds (herbicides), fungi (fungicides) and
insects (insecticides).

Question 10

define chemical fertiliser

Answer 10

include the elements NPK and increase plant growth.

Question 11

disadvantage of overgrazing

Answer 11

cause soil compaction, reducing air spaces and inhibiting nitrogen
fixing and nitrifying bacteria – leading to a loss of soil fertility
Water is also unable to penetrate compacted soil and grass growth is inhibited.

Question 12

define deforestation

Answer 12

is the removal of trees to use as timber or fuel or to
repurpose the land use for agriculture or building.

Question 13

consequences of deforestation

Answer 13

Soil erosion
 Lowland flooding
 Desertification
 Habitat loss
 Decrease in biodiversity
 Climate change

Question 14

what is coppicing

Answer 14

tree trunks are cut at their base, leaving a stool (stump) a few
centimetres above the soil. New shoots grow from the stool which can be harvested
at different diameters for different purposes e.g. building, fencing or fire wood.

Question 15

ways to manage forest woodland

Answer 15

Selective cutting
coppicing
Long rotation time

Question 16

disadvantage of overfishing

Answer 16

depletes fish stocks. Fish populations may become too low to recover – they
are no longer viable. This also impacts food chains and entire ecosystems.

Question 17

ways to preserve fish stocks

Answer 17

 Regulating mesh size
 Quotas and landing size regulations
 Exclusion zones
 Marine stewardship council certification
 Legislation limiting the size of fishing fleets or
controlling the number of days spent at sea
 Fishing alternative, non-traditional, species
 Using lines not nets

Question 18

what is fish farming

Answer 18

intensive farming where fish are bred and mature in enclosed ponds. Food, predation, disease and parasites are controlled. Warm water is used to
accelerate growth.

Question 19

disadvantages of fish farming

Answer 19

1.Rapid spread of disease and parasites due to the
high density of the farmed population
2. pesticides bioaccumulate
3.nitrogenous waste pollution
4.the escape of farmed fish may carry disease and parasites to wild population
5. farmed fish are larger and outcompete wild fish
6.farmed fish are fed on feed derived from other fish
7. farmed fish contain high levels of toxic chemicals such as methyl mercury

Question 20

factors that can be monitored

Answer 20

 Air quality
 Soil quality
 Water quality – including chemical, biological and microbiological aspects

Question 21

what is planetary boundary

Answer 21

‘safe operating space’ for
all of humanity, including all governments, organisations and
communities, as a precondition for sustainable development

Question 22

what are the 9 planetary boundaries

Answer 22

land use
ocean acidification
climate change
ozone boundary
chemical pollution
biodiversity boundary
aerosol boundary
fresh water boundary
nitrogen boundary

Question 23

which boundaries have been crossed

Answer 23

land use
biodiversity
climate change
nitrogen

Question 24

why is conservation of gene pools important

Answer 24

1. future medicines
2. future food sources
3. selective advantages - to prevent extinction

Question 25

what is agriculture exploitation

Answer 25

the increase in effeciancy and and intensity of food production in order to meet growing demands

Question 26

what is deforestation

Answer 26

the removal of trees from land which is subsequently used to grow crops and provide space for cattle

Question 27

outline consequences of deforestation

Answer 27

1. loss of biodiversity 2. climate change 3. soil erosion 4. desertification 5. lowland flooding 6. loss of habitat

Question 28

ways of forest management

Answer 28

1. coppicing 2. selective cutting 3.long rotation time

Question 29

what is overfishing

Answer 29

is where fish are caught at a higher rate than they reproduce and grow. This occurs to the point where increased fishing efforts lead to declining catches.

Question 30

methods to limit overfishing

Answer 30

● Using lines rather than nets ● Regulating net size ● Fishing quotas and exclusion zones ● Avoiding overfished species, fishing non-traditional species ● Limiting fishing fleet sizes ● Marine stewardship council certification ● Fish farming

Question 31

what is fish farming

Answer 31

breeding of fish commercially in enclosures for food to combat overfishing

Question 32

problems of fish farming

Answer 32

● Rapid spread of disease ● Escape of farmed fish ○ Spread disease to wild populations ○ Larger, outcompete wild populations ● Bioaccumulation of pesticides ● Farmed fish contain high concentrations of toxic chemicals (e.g. dioxins, PCBs

Question 33

define sustainability

Answer 33

Using resources in a way that also maintains them for future generations.

Question 34

Environmental monitoring is required for conservation. Give some examples of factors that can be monitored.

Answer 34

1. air quality 2. soil quality 3. water quality

Question 35

how many planetary boundaries have been crossed

Answer 35

4

Question 36

which who PBs are avoidable

Answer 36

1. fresh water use 2. ocean acidification

Question 37

which PB has been avoided

Answer 37

ozone depletion

Question 38

which PB is unquantified

Answer 38

1. aerosol 2. chemical pollution

Question 39

define extinction

Answer 39

total loss of species