3.6 Human Impcact On The Environment

Question 1

Define extinction

Answer 1

the complete loss of a species

Question 2

Why would a species become endangered

Answer 2

Natural selection due to changing selection pressures
Non contiguous populations - populations which are too small with insufficient genetic diversity to ensure a healthy and viable increase in number.
Loss of habitat - eg deforestation
Over hunting by humans - overfishing
Competition from introduced alien species.
Pollution due to human activity- oil and PCB

Question 3

Define conservation

Answer 3

the sensible management of the biosphere and enhancement of biodiversity locally

Question 4

What are Examples of conservation methods

Answer 4

Habitat protection eg nature reserves, SSSI
International cooperation restricting trade eg CITES
Gene and sperm banks
Seed banks
Rare breed societies
Species reintroduction
International organisations eg WWFN
Legislation
Ecotourism

Question 5

Define endangered species

Answer 5

A species considered to be in imminent danger of extinction.

Question 6

How can gene pools be conserved in the wild

Answer 6

Through the establishment of protected areas, habitat restoration and legal protection of species.

Question 7

Why is conserving gene pools important

Answer 7

Ensures the survival of species in their natural environment, maintains biodiversity.
Prevents the loss of potentially useful genes that could be used in medicine, agriculture or industry.

Question 8

How are gene pools conserved in captivity

Answer 8

Captive breeding programmes
Seed banks
Zoos

Question 9

What are the ethical reasons for conserving gene pools

Answer 9

Humans have the responsibility to protect other species, ensure their survival and prevent extinction caused by human activity.
It’s unethical to let species go extinct due to human activity.

Question 10

Define agricultural explotiation

Answer 10

The increase in efficiency and intensity of food production in order to meet growing demands

Question 11

What conflicts are caused between agricultural production and conservation

Answer 11

Demand for food production leads to habitat lost, deforestation, monoculture practices and reduced biodiversity

Question 12

Define deforestation

Answer 12

Complete loss of trees in a defined area due to human activity

Question 13

What are the consequences of deforestation

Answer 13

Soil erosion - nutrient losss
Lowland flooding
Desertification
Habitat loss
Decreased biodiversity
Climate change

Question 14

How can we manage deforestation

Answer 14

Implementing sustainable replanting
Long rotation times
Coppicing - leaving a stump
Selective cutting

Question 15

What is a monoculture and how does it reduce biodiversity

Answer 15

Reduces biodiversity by offering only one habitat. Growth of genetically identical crops in a large area.

Question 16

What are the consequences to using monocultures

Answer 16

Depletes soil nutrients as plants extract minerals at the same depth increasing the need for chemical fertilisers

Question 17

Why do monocultures increase pesticide use

Answer 17

Plants grow close together and are genetically identical making them vulnerable to the same pests and diseases

Question 18

What is overgrazing and what are its harmful environmental effects?

Answer 18

Animals graze for too long, damaging the grasses. Exposes soil to erosion and compacts soil, reducing air spaces and inhibiting nitrogen fixing and nitrifying bacteria.
Water is unable to penetrate through compacted soil and grass growth is inhibited

Question 19

What are the disadvantages to intensive fish farming

Answer 19

Rapid spread of disease and parasites due to high density of farmland increasing use of pesticides entering food chain
Pesticides then accumulate causing reduction in fertility at higher trophic levels
Nitrogenous waste pollution leading to eutrophication
Escaped farmed fish may carry disease and parasites to wild population
Farmed fish outcompete wild fish for resources if they escape

Question 20

What toxic substances are in farmed fish

Answer 20

Methyl mercury
Dioxins
Pesticides
PCBS

Question 21

What are methods to reverse decline in biodiversity

Answer 21

Organic farming
Set aside schemes
Replanting hedgerows
Legislations like environment act

Question 22

How does organic farming increase biodiversity

Answer 22

Reducing chemical fertilisers and pesticides, allowing crop rotation and growing a variety of crops to provide different habitats

Question 23

What is overfishing

Answer 23

capturing fish faster than they can reproduce impacting food chain

Question 24

What fishing methods contribute to overfishing

Answer 24

Trawling
Drift netting

Question 25

What is drift netting

Answer 25

A net suspended from floats stretched between two boats, thousands of miles of net is set and non target species are often caught eg dolphins

Question 26

What is trawling

Answer 26

Weighted nets dragged across ocean floor. This method catches everything and damages the ocean floor decimating habitats for miles

Question 27

How to we preserve fish stocks

Answer 27

Regulate mesh size Exclusion zones Using lines not nets Legislations limiting the size of fishing fleets or controlling number of days spent at sea Fishing alternative.

Question 28

How can science and technology contribute to sustainability

Answer 28

By predicting affects of human activity and develop sustainable alternatives to create countermeasures to harmful practises

Question 29

Why is environmental monitoring essential for conservation

Answer 29

Tracks changed in ecosystems and predicts future impacts so countermeasures can be prepared or activities planned can be replaced with other less harmful consequences.

Question 30

What are planetary boundaries?

Answer 30

A set of nine limits proposed by a group of environmental and Earth system scientists within which human activity can operate without risk of irreversible damage to the planet.

Question 31

Why are planetary boundaries important

Answer 31

To prevent IRREVERSIBLE and abrupt environmental changes caused by human activities.

Question 32

What are the 9 planetary boundaries

Answer 32

Biodiversity boundary Climate change boundary Nitrogen boundary Land use boundary Chemical pollution boundary Fresh water boundary Aerosol boundary Ocean acidification boundary Ozone boundary

Question 33

What is the biodiversity boundary and has it been crossed

Answer 33

Relates to species extinctions and natural selection, change in habitats such as maurine and tundra -has been crossed.

Question 34

Effects of crossing biodiversity boundary

Answer 34

V Extinction disrupts ecosystems and reduces biodiversity

Question 35

What causes the crossing of the climate change boundary

Answer 35

Increased greenhouse gas emissions eg CO2 due to human activity Production and use of biofuels instead to prevent this.

Question 36

What are the effects of crossing the climate change boudary

Answer 36

Disrupted ecosystems Altered human plant and animal reproduction

Question 37

What causes crossing of nitrogen boundary

Answer 37

Excess nitrogen from fertilisers lead to eutrophication in ecosystems

Question 38

What are the effects of eutrophication

Answer 38

Algae blooms reduce oxygen levels harming aquatic organisms

Question 39

What is the land use boundary

Answer 39

Involves land exploitation for farming and urbanisation, it can be avoided.

Question 40

What is the fresh water boundary and can it be avoided

Answer 40

Ensures the availability of fresh water for ecosystems and human use. It can be avoided.

Question 41

How can we ensure fresh water availability

Answer 41

Desalination

Question 42

What causes chemical pollution and is it quantified

Answer 42

Caused by SO2 AND N oxides It's unquantified

Question 43

What are the effects of chemical pollution

Answer 43

Acid rain damaging soil, water and organisms

Question 44

What causes the aerosol boundary to be crossed

Answer 44

Air pollution from particulate matter eg soot, dust

Question 45

What are the effect of crossing aerosol pollution

Answer 45

Poor air quality, harm to human health

Question 46

What causes ocean acidification and can it be avoided

Answer 46

Burning fossil fuels increased co2 leading to acidification It can be avoided

Question 47

What are the effects of ocean acidification

Answer 47

Damages marine ecosystems eg coral reefs and fish farming

Question 48

What causes ozone depletion and has the boundary been avoided

Answer 48

Causes by CFC emission Boundary has been avoided due to Montreal protocol

Question 49

How has ozone depletion boundary been avoided

Answer 49

International cooperation and banning of CFCS

Question 50

What are the planetary boundaries that have been crossed

Answer 50

Biodiversity boundary Climate change boundary Nitrogen boundary

Question 51

What are the planetary boundaries that are avoidable

Answer 51

Land use boundary Fresh water boundary Ocean acidification boundary Ozone depletion boundary

Question 52

What are the planetary boundaries that are unquantified

Answer 52

Aerosol boundary Chemical pollution boundary

Question 53

Explain how deforestation affects the planetary boundary for climate change

Answer 53

Deforestation reduces the uptake of carbon dioxide Burning of trees puts carbon dioxide into atomosphere Decay of waste tree material.