Human Impact On The Environment Flashcards
(111 cards)
1
Q
Define the term endangered
A
A species which has few numbers in total population. At risk of extinction.
2
Q
Define the term extinction
A
There are no living organisms of that species left
3
Q
Define the term conservation
A
The protection, preservation, management and restoration of natural habitats and their ecological communities while allowing suitable human activity
4
Q
Define the term ecotourism
A
Responsible travel to natural areas that conserves the environment and improves the well being of local people
5
Q
Define the term monoculture.
A
The growth of large numbers of genetically identical crop plants in a defined area
6
Q
Define the term soil erosion
A
The removal of fertile topsoil which contains all of the valuable nutrients
7
Q
Define the term coppicing
A
Cutting down of trees close to the ground and leaving to regrow for several years
8
Q
Define the term over fishing
A
The rate at which fish are harvested is greater than the rate of reproduction.
9
Q
Define the term planetary boundaries
A
Limits between which global systems must operate to prevent abrupt and irreversible environment change
10
Q
Define the term core boundary
A
Crossing this boundary would drive the earth into new and unpredictable state with severe consequences for the biosphere
11
Q
Define the term global warming
A
The increase in global average temperature in excess of the greenhouse effect caused by the atmospheres historical concentrations of co2
12
Q
Define the term biofuel
A
A fuel made by a biological process like anaerobic digestion rather than geological processes that formed fossil fuels
13
Q
List some causes of extinction caused by humans
A
- deforestation
- habitat destruction
- over hunting
- competition from introduced species.
14
Q
List some conservation methods
A
- legislations to prevent overhunting or overfishing
- seeds and spent banks
- habitat protection and nature reserves
- breeding endangered species in zoos
15
Q
Why do we want to conserve species and gene pools at risk of becoming extinct?
A
The species could give useful genes to aid humans for medical use if qualities are not yet known
16
Q
What are some reasons for deforestation?
A
- to sell high quality/valued trees like mahogany
- timber used as fuel or building material
- clear land for farming or cattle grazing
- space for roads and housing
17
Q
List some consequences of deforestation
A
Reduced biodiversity
Habitats are destroyed
Soil erosion
Lowland flooding
18
Q
How can forests be managed?
A
Coppicing Conservation Controlling pests and disease Selective cutting Log rotation time
19
Q
What is overfishing?
A
When fish are harvested faster than they can reproduce to repopulate so populations decreases
20
Q
What measures can be put in place to prevent overfishing?
A
Quotas Seasonal fishing Restricted areas Legislation on net mesh size Legislation of boat numbers in a fleet
21
Q
Describe the steps of eutrophication
A
- nitrates form fertilisers leached into lakes from soil
- plants respond to fertiliser in the water causing an algal bloom
- this causes restricted light to the aquatic plants so unable to photosynthesis was much so they die and lack of oxygen in water
- these pants are decomposed by saprobionic fungi which creates a lack of oxygen in the water as they use it to respire.
22
Q
Why is environmental monitoring needed?
A
It will describe the quality of the environment to help identify patterns in data to help make future predictions.
23
Q
What are some advantages of biofuels?
A
Reduces loss of fossil fuels and carbon dioxide emissions
Can use waste products from farming to be more sustainable.
24
Q
List some disadvantages of biofuels
A
- uses land which could be used by crops for food or wildlife
- deforestation to make space to grow crops leading to erosion and reduced biodiversity
- biodiesel produces more NO2
- fossil fuels still used like for transport, processing and harvesting.
25
What is natural selection?
Occurs when individuals less suited to prevailing conditions reproduce less successfully
Their numbers decrease which may lead to extinction
26
How does human activity affect natural selection?
Human activities are causing habitats to change faster than mutations allow species to adapt, so they are driven to extinction at a faster rate than before human influence.
27
Name some methods of habitat destruction
Deforestation, drainage of wetlands, hedgerow removal
28
How does hedge row removal destroy habitats for other organisms?
They provide habitats for insects, nesting sites for birds and reptiles, food for many species, varying light intensity and water availability for diverse plants. Shelter for animals moving around from predators
29
Why are hedgerows removed?
Space for large agricultural machinery
30
Give examples of overhunting and collecting
```
Trophy hunting
Traditional medical practices
Bush meat industry
Overfishing
Agricultural exploitation
```
31
Give examples of how competition from reintroduced species have caused threats to other species
- dodo driven to extinction due to rats from European ships eating the eggs
- red squirrels out competed by grey squirrels in uk due to loss of habitat
32
How is pollution putting species at danger of endangerment and extinction?
- oil shipped worldwide in supertankers, accidental discharge of oil in sea when ship runs aground. Contaminated potable water and killed plants and animals
- oil floats on surface of water, so when animals break through the surface of the water, they are covered by a film of oil. And washed up on shore and ingested by animals which are ten poisoned
- PCBs are infested with food can still be detected in waste water around old quarry’s even through they were banned.
33
What is conservation?
The sensible management of the biosphere to maintain habitats and enhance biodiversity while allowing human activity.
34
Why is conservation important?
To maintain genetic diversity both in the wild and in captivity.
35
List methods of conservation
- nature reserves
- international cooperation restricting trade
- breeding programmes (zoos and botanic gardens)
- sperm banks
- seed stores
- reintroduction programme
36
Explain the importance of nature reserves and sites of special scientific research
For habitat protection
It protects the species that live there and the community acts as a living gene bank
Official designation recognised local nature reserves sometimes as small as a few hectares
37
Explain the importance of international cooperation restricting trade
Like the ivory trade and whaling
| International laws allow some countries to practice whaling although there are many organised attempts to stop it.
38
Explain the importance of breeding programmes like zoos and botanic gardens
For endangered species like pandas which are protected and entered into breeding programmes in specialised zoos and botanic gardens
Records of mating are kept so genetic diversity can be increased by deliberate choice of parents to form a gene bank.
39
Explain the importance of sperm banks
Used to store genes of economically important animals and threatened species
Rather then moving animals, sperm samples are sent around the world to use in breeding programmes of other zoos
40
Explain the importance of seed stores during conservation
Maintain stocks of seeds of traditional varieties and of vulnerable species in highly controlled conditions of liquid nitrogen.
Seeds degrade over time so periodically seeds are thawed and germinated and a new generation of seeds is collected and stored from there.
41
Explain the importance of the reintroduction programme during conservation.
Following successful breeding programmes some species are reintroduced into the wild and former habitats like the red kite and the chough
42
Describe ecotourism and how it helps conservation
It recognises that mass travel is harmful globally and to specific habitats. It aims to:
- contribute to conservation efforts
- employ local people and give money back to local communities
- educate visitors about local environment and culture
- cooperate with local people to manage natural areas.
43
Why should existing gene pools be conserved?
- ETHNICALLY each species is unique band valuable
- AGRICULTURE selective breeding loses rare alleles and some past breeders may have neglected qualities like agriculture
- ENVIRONMENT changes. Some alleles are advantageous to the individual to survive changes in the environment.
- MEDICAL many antibiotics are derived from fungi and plants. If species become extinct we may lose potential drugs we haven’t yet discovered.
44
Define agricultural exploitation
Producing that quality and quantity of food required to feed the increasing human population.
45
What are the implications involved with agricultural exploitation?
- many hedgerows removes to make larger fields to enable machinery to prepare soil and harvest crops
- monoculture crops in the field like wheat and barley only provides one habitat reducing species diversity as if a mix of crops were grown, then many different micro habitats would form, allowing more species to live there
- reduced crop yield year on year
- overgrazing
46
Why does crop yield progressively define if the same crop is grown in the same field year after year?
- roots are always the same length so they extract the same minerals from the same depth soil increasing the use of inorganic fertilisers
- same species is always susceptible to the same pests which increases the number of insecticides, herbicides and fungicides used.
47
How does overgrazing by cattle cause grassland to become unsustainable?
Their hooves compact the soil, driving out the air and preventing water draining through. Roots cannot penetrate the soil and so grass for grazing cannot grow.
48
What are the reasons for deforestation?
- timber used for fuel and building material
- paper and packaging
- land cleared for farming to produce biofuels or cattle for meat industry
- high value trees to sell and their removal will damage other trees in the process
- new roads for transport in these activities
49
What are the consequences of deforestation?
- soil erosion
- lowland flooding
- diminishes quality of soil
- less rainfall
- habitat loss and reduced bio diversity
- effects atmosphere
50
How does deforestation affect soil erosion?
Tree roots binds the soil together, so on steep slopes, rainfall will sweep loose top soil down hill to the flood plains below. Without the top soil (which holds all the valuable nutrients) crops and trees cannot grow.
51
How does deforestation cause lowland flooding?
Trees are taken up, upland which causes more water to sweep down hill as less is absorbed by higher soil causing lowlands to flood.
52
How does deforestation diminish the quality of the soil?
No plants for water uptake so the water evaporates. This returns water vapour into the atmosphere more slowly than transpiration so souls becomes wetter and water fills the airspaces so no oxygen available to the roots.
It takes longer for wet soil to heat up than dry soil so always cold meaning seeds cannot germinate abs root activity is reduced.
Cold soil also favours the growth of denitrifying bacteria so souls loses fertility.
53
How does deforestation lead to less rainfall?
Water only returns to atmosphere by evaporations from soil as there is no longer transpiration (which is quicker than evaporation). This accelerated denitrification.
54
How does deforestation contribute to habitat loss and reduced biodiversity?
Destruction of habitats leads to loss of species. Some may become extinct before our knowledge of clinical properties. More competition for habitats left in the trees.
55
How does deforestation affect the atmosphere?
Photosynthesising trees are cut down, removal of co2 in atmosphere is reduced as less photosynthesis.
Trees cut may be left to burn or decay which releases more co2 into the atmosphere.
56
How can we manage our forests?
Coppicing
Log Rotation times
Selective cutting
57
Describe and explain coppicing
The tree trunk is cut and a “stool” is left so that new shoots emerge from buds in stool and grow into poles which thicken over the years
Poles can then be cut in rotation to produce timber of different widths
Can regenerate over time
58
Describe and explain how we can use log rotation times to nagar our forests
It will increase sustainability as many years are left between harvesting so a variety of habitats develop, favouring diverse wildlife.
59
How can selective cutting help manage our forests?
Instead of removing all trees in one area at a time, only a select few are cut.
This is especially food on steep slopes, to prevent erosion
It helps to maintain soil nutrients and minimalists soil washed down into nearby water ways.
60
How does the genetic diversity of fish decreases due to overfishing?
Smaller nets have been used to catch fish, so fish are being caught before sexual maturity. This means that there are fewer individuals able to mate so population size decreases.
61
What are some examples of commercial fishing?
Drift netting
| Trawling
62
Describe the process of drift netting
Pelagic fish live on the surface of water and caught in nets and stretched between to boats.
This causes non target species like turtles and dolphins to be caught and trapped accidentally.
63
Describe the process of trawling.
Fish that live in deeper water are caught by large nets being dragged through the water, catching whatever swims in to it. Trawling equipment has damaged the ocean bed and destroyed habitats of molluscs and other organisms, putting their populations at risk.
64
List some methods of regulating fishing
- mesh size
- quotas
- exclusion zones
- size of boat fleets
- number of days spent at sea
- fish farming
65
Explain what fish farming is.
Fish are bred and grown to maturity in ponds lakes and in managed enclosures to reduce predation and food source is maintained.
Artificial fertilisers are added to water to help growth of phytoplankton
Fish can be farmed in pods which can be moved to more favourable conditions depending on ocean currents local water temp and other biotic factors.
66
What are some advantages of fish farming compared to pork Paul try it beef?
- fish concert their food to protein more efficiently
- greater proportion of their bodies are edible
- lower carbon footprint
67
What are some disadvantages of fish farming?
- DISEASE are easily transmitted as the fish are densely stocked and huge doses of antibiotics are required to keep them healthy and pesticides to control parasites harm marine invertebrates
- POLLUTION like eutrophication due to the use of fertiliser into water outside of the pens
- ESCAPED fish may outcompete those found in the wild as they compete for food, habitat and mates. And transport disease
- RESOURCE usage some fish feed of of smaller fish seen as a waste of resources
- TOXINS in environment found more concentrated inside of farmed fish
68
What is environmental monitoring?
It describes the quality of the environment and the pattern of the data is used to identify trends and make predictions
69
What are some types of environmental monitoring?
- air quality
- soil
- water quality (chemical, biological, microbial)
70
Describe what air quality monitoring is
The concentrations of air pollutants are measured as they are associated with the health risks when exposed to them. It is carried by the wind so must be taken into account when identifying the source.
71
What is soil monitoring?
Looks at soil structure, density, water holding and drainage capacity,PH, organic particles etc
72
Describe water chemical monitoring
Acid rain and greenhouse gases have made water monitoring essential. Like the oestrogen affect on the water due to the use of hormonal contraceptives used in industry.
73
Describe water biology monitoring
Animals can act as an indicator species for water quality, like when a steep decline in salmon population indicates acid rain
74
Describe water microbial monitoring
Bacteria and viruses are monitored especially for potable water many sewage treatment plants don’t sterilise the water they released.
75
What is an environmental impact assessment?
Documents aiming to predict environmental effects of a proposed project when activities risk harming the environment
76
What is sustainable development?
Development to meet the needs of present generation without compromising the ability of future generations to meet their needs.
77
What are planetary boundaries?
Limits between which global systems must operate to prevent abrupt and irreversible environmental changes
78
How many global boundaries have been exceeded their upper limit?
4
79
Name the nine global boundaries
- climate change
- biosphere integrity
- land-system change
- biochemical flows
- ocean acidification
- stratospheric ozone
- fresh water use
- atmospheric aerosol loading
- novel entities
80
Which global boundaries have already been crossed?
- biosphere integrity
- climate change
- land-system change
- biogeochemical flows
81
Describe the climate change boundary
It has already been crossed
| Greenhouse gases have been emitted into atmosphere so average global temperature has risen
82
Describe the biosphere integrity boundary
Has already been crossed
| Ecosystem services like mineral cycling on which the biosphere depends
83
Describe the land-system change boundary
It has already been crossed
| Deforestation and urbanisation
84
Describe the II geochemical flows boundary
Has already been crossed
| It’s the cycling on minerals through biotic and abiotic components
85
Describe the stratospheric ozone boundary
This boundary has been avoided
Halogenated hydrocarbons like CFCs react with ozone causing it to break down leading to and increase of UV rays reaching the earth
86
Describe the ocean acidification boundary
The ocean PH is falling due to more CO2 dissolving in ocean to produce more hydrogen carbonate ions. This boundary is not yet crossed
87
Describe the fresh water usage boundary
Availability of fresh water, below it, there isn’t enough fresh water for organisms to survive
This a boundary is avoidable
88
Describe the atmospheric aerosol loading boundary
The boundary is not yet established.
| Microscopic particles into atmosphere by the combustion of fuels and dust from quarrying
89
Describe the introduction of novel entities boundary
This boundary is not yet established.
| Organic pollutants, radioactive materials, nano materials, micro plastics.
90
How can biofuels be made?
Biological processes like anaerobic digestion of plant material and domestic and industrial waste
91
How are first generation biofuels made?
Made from sugars and vegetable oils found in arable crops and easily extracted
92
How are second generation biofuels made?
Cellulose and lignin from woody crops. Harder to extract than first generation
93
Name some social, economic and technical issues with the production of biofuels
```
Food vs fuel
Carbon emissions
Sustainable biofuel
Deforestation
Reduction in water availability
Combustion of biodiesel
```
94
How is bioethanol made?
- plant material crushed and stored starches are digested with carbohydrases to release sugars
- sucrose is crystallised our leaving molasses rich in glucose and fructose
- glucose and fructose are fermented by yeast to produce an ethanol containing mixture
- mixture is heated, burning fibrous waste from the initial material and pure ethanol is distilled
95
What is biodiesel made from?
Vegetable oils like soya of crops which have been grown for their long chain fatty acid content
96
What are the advantages of using biofuel?
- produces less carbon particles and less carbon monoxide.
- more hydrogen and oxygen than petrodiesel
- produces more nitrous oxides
97
What is biogas made of?
60%methane and 40% carbon dioxide
98
How do you make biogas?
- macromolecules I’m waste material is aerobically digested by enzymes into sugars, fatty acids and glycerol and amino acids
- acetogenesis produces short chain fatty acids
- methanogenesis (anaerobic) c6h12o6 => 3ch4 + 3co2
- solid material left over is dried and used as biofuel it fertiliser.
99
What does the biochemical flow boundary refer to?
The cycling of minerals through biotic and abiotic components of the ecosystem.
Carbon. Sulphur. Phosphorus. Nitrogen.
100
Why are mineral cycles important?
They are essential to maintain availability of elements in ions transmitted through the food web due to agricultural fertilisers being excessively used
101
What are the consequences of ocean acidification?
- low ph leaches calcium carbonate from shells and anthropoid exoskeletons, softening them and making them more vulnerable to physical and chemical attacks
- low ph will affect the fish gill structure and functioning is damaged so that they receive oxygen less efficiently.
102
How does a higher co2 level in atmosphere make water in oceans more acidic?
- co2 from air dissolves in bodies of water as hydrogen carbonate, releasing a h+ ion
- hydrogen carbonate ions break down the carbon ions and hydrogen ions.
- the bigger the h+ ions concentration the lower the ph, making water more acidic
103
What causes the stratospheric ozone to break down?
Normally it is at equilibrium 3O2 <=> 2O3
| But halogenated hydrocarbons Alger the position of the equilibrium to favour the break down of ozone
104
Why is having an increased UV-B intensity dangerous?
It is strongly absorbed by dna causing and increase in skin cancers and cataracts.
105
Why is there a diminished supply of fresh water?
- changing landscapes
- agriculture consumes more fresh water than any other human activity
- water pollution
- climate change
- increase in population through increasing life expectancy
106
What are two methods of water desalination?
Solar stills
| Reverse osmosis
107
Describe the process of solar stills for desalination
Distill seawater using heat from the sun.
| No air pollution or warm water discharges which may endanger local lakes or rivers
108
Describe the process of reverse osmosis for desalination
Sea water separated from fresh water using a selectively permeable membrane. Pressure is applied against osmotic gradient against water potential gradient. Mostly powered by fossil fuels or nuclear power.
109
What are some environmental problems with desalination?
- brine (concentrated sodium chloride solution) is discharged. Denser than sea water so sinks and damages the sea bed ecosystem
- burning fossil fuels to generate heat and run the system.
110
What are atmospheric aerosols?
The microscopic particles put into the atmosphere by the combustion of fuels and by creating dust from digging and quarrying.
111
What is the problem with atmospheric aerosols?
- They create respiratory problems causing death from lung disease
- reduces light absorption for photosynthesis so crop yields are reduced
- sulphates in aerosols reflect light providing a cooling effect
- other particles like soot irridate it and increase its warming
