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Organisms And Their Environment > Global change in populations > Flashcards

Global change in populations Flashcards

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1
Q

What are the main causes of global change been in the past

A

solar variation, plate tectonics, volcanism, proliferation and abatement of life, meteorite impact, resource depletion

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2
Q

What are the main causes of global change now

A

growing human population, demand for energy, food, goods, disposal of waste products

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3
Q

What has global change caused

A

climate change, species extinction, desertification and ocean acidification, ozone depletion and pollution

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4
Q

Define pollution

A

: introduction by humans into the environment of substances or energy liable to cause hazards to human health, harm to living resources and ecological systems , damage to structures or amenity, or interferences with legitimate uses of the environment.

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5
Q

Forms of pollutants

A

foreign substances or naturally occurring, chemical or energy e.g., noise, heat or light

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6
Q

What does how toxic a pollutant is depend on

A

amount, concentration, where it is

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7
Q

Define lethal concentration

A

concentration of the chemical in the air or water that will kill 50% of the test animals with a single exposure

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8
Q

Define lethal dose

A

the single dose of a chemical that, when fed to a group of test animals or applied dermally, will kill 50% of the animals

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9
Q

what is an additive effect of pollutants

A

effects of each may be added together to indicate the overall effect

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10
Q

What is antagonistic effect of a pollutant

A

one pollutant may cancel out or reduce the impact of another

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11
Q

What is a synergistic effect of a pollutant

A

pollutants combine in such a way that the environmental effects are greater than would be expected additively

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12
Q

Sources of pollution

A

point source (e.g., sewage outlet), multi-source (e.g., chimney stacks), seeping (fertiliser run off), spreading (volatiles in air flows)

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13
Q

What are the characteristics of acute pollution

A

Occurs when a large amount of waste matter enters the environment

Usually from a point source, after a one-off accidental event

Commonly has a toxic effect on biota

After event ecosystem begins to recover and returns to resemble original situation

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14
Q

Acute pollution: oil

A

Crude oil is a blend of many chemical compounds. Aliphatic hydrocarbons (hexane) , Aromatic hydrocarbons ( benzene), Polar compounds ( ethanol), Sulphur compounds (benzothiooenes)

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15
Q

Acute pollution of oil biotic effects

A

Around 90% of sunlight is intercepted. Division of algal cells is inhibited at oil levels of as 0.01pp, Food chains are modified (directly and indirectly)

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16
Q

Characteristics of chronic pollution

A

Low-level input into the environment. Occurs either more or less continuously or as frequent pulses. Environment is constantly under stress, albeit light stress. Ecosystem does not have opportunity to recover and often there is an accumulative effect

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17
Q

Chronic pollution: pesticides

A

Highly toxic chemical substances deliberately introduced into an ecosystem to kill or reduce population size or growth of particular pests or weeds

Saved many human lives: major players in increases in food and other organic products over past 40 years

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18
Q

What are the benefits of pesticides

A

reduction in impact of weeds and pests, improved harvests, fewer storage losses, control of human livestock and crop diseases

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19
Q

Chronic pollution: DDT and peregrine falcon

A

DDT: dichlordiphenyltrichloroethane

By early 1960s UK and USA were commonly using DDT as generalist pesticide

1961 British Trust for Ornithology (BTO) found that breeding numbers of peregrine falcons (falco peregrinus) were falling dramatically

High residues of DDE (the stable metabolite of DDT) found in the fatty tissues of peregrine caracasses and in eggs

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20
Q

Types of pesticides - organochlorine

A

DDT, aldrin, dieldrin and heptachlor – blood spectrum toxins, remain in the environment for a long time

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21
Q

Types of pesticides - chlorophenoxy

A

herbicides such as 2,4 – D. Chemistry resembles that of plant auxins. Broken down in soil in a meter of days

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22
Q

Types of pesticides - organophosphates

A

malathion, parathion and carbamates. highly toxic to humans. biodegradable and non-persistant, readily broken down

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23
Q

What is biomagnification

A

occurs when an element or chemical compound moves from one compartment to another and occurs at a higher concentration in the second.

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24
Q

What is concentration factor

A

concentration of the pollutant in the consumer ÷ concentration of the pollutant in the diet.

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25
When does biomagnification occur
when concentration factor > 1
26
How has plastic become a problem
Accumulation of plastic products in the environment adversely affecting wildlife, habitat or humans. Prominence correlated with plastics being inexpensive and durable. Slow to degrade.
27
Affects of plastic pollution
Affects lands, waterways and oceans. Marine animals: entanglement, direct ingestion, or through exposure to chemicals causing interruptions in biological functions. Humans: disruption of thyroid hormone levels.
28
What are microplastics
small particles usually < 5mm in diameter
29
Sources of microplastics
cosmetics, clothing and industrial processes
30
What are primary microplastics
manufactured, direct result of human material and product use.
31
What are secondary microplastics
fragments derived from the breakdown of larger plastic debris
32
How are microplastics an issue
persist in the environment at high levels, particularly aquatic and marine ecosystems. Can be ingested and incorporated into and accumulated in the bodies and tissues of many organisms
33
What is holocene extinction
Sixth extinction or Anthropocene extinction: ongoing extinction event of species, mainly due to human activity.
34
Species extinction stats:
> 90% all species ever existed now extinct. Estimate: 100-150 species of plant, insect, bird and mammal become extinct every 24 hours. 100 to 1,000 times the “natural” or “background” rate.
35
What are the main causes of extinction
Habitat fragmentation, agriculture, human over-population (demand for more resources), deforestation, poaching and hunting
36
Define biodiversity
he variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems.
37
Define genetic diversity
total number of genetic characteristics in the genetic makeup of a species.
38
Define genetic variability
tendency of genetic characteristics to vary.
39
What is sepcies richness
count of species
40
What is species eveness
how equal the abundances of each species are
41
Define ecosystem diversity
variation in ecosystems found in region or variation in ecosystems over the whole planet.
42
Ecosystem diversity
Can take into account the variation in complexity of a biological community, number of trophic levels and other ecological processes. Is the largest scale of biodiversity, and within each ecosystem, there is considerable species and genetic diversity.
43
What is gamma diveristy
total species diversity in a landscape
44
What is gamma diversity determined by
alpha and beta diversity
45
What is alpha diversity
the mean species diversity in sites or habitats at a more local scale
46
What is beta diversity
the differentiation among those habitats
47
Define endemism
a term used to describe the usually limited geographical distribution of a taxonomic group, usually at family, genus or species level.
48
What is usually a biodiversity hotspot
Areas of high species richness and a high level of endemism are generally areas of high conservation value
49
How many areas in the world are considered to be biodiversity hotspots
36 - support nearly 60% of the worlds diveristy
50
What is a direct use value
derived from direct role of biological resources in consumption and production
51
What is an indirect use value
derives from the many functions biodiversity performs in providing services critical to human well- being
52
What is a non-use value
value associated that does not concern our use, either direct or indirect, of the environment, its resources or services.
53
How is biodiversity useful to us
provides food (meat, fruit, nuts, etc), drugs
54
What % of our food comes from 20 different plants
80
55
What % of weed and pest control are based on biocontrol
30% - weed 40% - insect
56
How much and what area is harvested for the world wide tree export
£4.5 billion and more than 3.8 million cubic meters harvested
57
What is the total global fish harvest
2015140 million tonnes. 66% of the world’s marine fish stocks estimated at being fished at, or beyond, their level of maximum productivity.
58
How has the sustainability of fuel wood become an issue
1.3 billion people in developing countries consuming fuel-wood faster than it is being replenished. If present trends continue, further 1 billion will face chronic fuel-wood shortage by 2050.
59
How many people take part in ecotourism per year
250 million
60
How much does ecotourism contribute to national income a year
80 to 250 billion
61
Define ecosystem processes
The physical, chemical and biological actions or events that link organisms and their environment.
62
Examples of ecosystem processes
decomposition, primary productivity, nutrient cycling, and fluxes of nutrients and energy.
63
Define ecosystem services
the benefits provided by ecosystems to humans.
64
What are the 4 groups of ecosystem services
Provisioning, (production of food and water), Regulating, (control of climate and disease), Supporting (nutrient cycles and crop pollination), Cultural (spiritual and recreational benefits)
65
How much is the short-term economic benefits of ecosystem services
25 trillion
66
What is the ecotron biodiversity experiment
experimental means for analysing population and community dynamics and ecosystem processes under controlled physical conditions. ecotron is an experimental ecology to study the impact on biodiversity of changes in the ecosystem
67
BIODEPTH experiment
investigates the impacts of reducing biodiversity on ecosystem structure and processes
68
What is climate change
a large-scale, long-term shift in the plant’s weather patterns or average temperatures.
69
How is solar radiation causing global warming
- solar radiation reaches surface - can be reflected back to space or absorbed by atmosphere - can be re-radiated back to surface - heat can be radiated back from surface and re-radiated out to space
70
What are the natural causes of climate change
solar activity, earth’s orbit (Milankovitch cycles), continental drift
71
What are the recent causes of climate change
El nino event, volcanic eruptions, greenhouse effect
72
Climate change history
1827 - Jean-Baptiste-Joseph Fourier - first recognised existence of “greenhouse effect” * 1860 - John Tyndall - measured absorption of infrared radiation by carbon dioxide (CO2 ) * 1896 - Svante Arrhenius - calculated effect of increasing concentration of greenhouse gases * 1940 - G S Callender - first to calculate the warming due to increasing CO2 from burning fossil fuels * 1957 - Roger Revelle and Hans Suess - first expression of concern about climate
73
How have CO2 levels changed
Increase of atmospheric carbon dioxide (CO2 ) since 1000 (from ice cores in the Antarctica). * Pre-industrial global average concentration of CO2 was 260 - 280 ppm. * 1990 CO2 level, about 350 ppm; 14 December 2022, about 417 ppm.
74
Name the green house gases
CO2, CH4, H2O, CFCs
75
Why is CH4 become a concern for climate change
about 25 times as effective (increased due to coal, waste, leaks, livestock and rice paddies)
76
Which gas is the main contributor to global warming
CO2
77
What are the effects of climate change seen in Wales
Sea levels at Holyhead have increased over the past 50 years Wheat crops at Aberystwyth flower 1-2 weeks earlier Blackcap arriving earlier on Skokholm Island
78
What are the consequences of climate change
Sea level rise, Effects on species, Distribution of species, Effects on agriculture, Patterns in disease, Human migration
79
What is the predicted sea level rise
PCC predicts that the average sea level will rise by 12cm by 2030 and 50cm by 2100. 50% of humanity inhabits the coastal zones around the world. Lowest lying some of the most fertile.
80
What is the sea level rise in the Netherlands
over 50% of the land below present sea level. 400km of dykes and coastal dunes provides protection. Estimated cost of protection against 1 m sea level rise: £10,000 million
81
What is the sea level rise in Bangladesh
About 30% of land below 2m contour above sea level. Estimates of sea-level rise. 120 million people located in delta region (Ganges and Brahmaputra)
82
What is the sea level rise in low-lying islands
0.5 million people live in archipelagos of small islands and coral atolls. 0.5 sea level rise in this rise would reduce habitable area and remove 50% of groundwater.
83
What is the sea level rise in freshwater
Climate change will affect ground water supplies and reserve in many ways. Demands of increasing population. Political – many of world’s major sources of water are shared
84
How do C3 plants respond to increased CO2 concentrations
increases photosynthesis
85
How else can plants respond to elevated CO2 levels
increasing the ratio of carbon to nitrogen
86
What can high CO 2 levels cause plants to do
partial closing of stomata, reducing transpiration and making plants more efficient in water usage.
87
By how much does doubling CO2 levels increase4 growth in C3 and C4 plants
C3 - 40% C4 - 20%
88
Effects of reduced transpiration
less irrigation, less water stress, high water use efficiency
89
Effects of increased carbon allocation below ground
more root development, higher microbial activity, improved water and nutrient uptake
90
How can highe4r CO2 effect leaves
thicker - more starch and more carbon based defences against herbivores
91
Indirect effect on insects of high CO2 levels in plants
Insects that eat plants usually limited by nitrogen supply – may need to consume more, they may develop slower.
92
How has plant distribution changed
there are lower populations of plants
93
Increased CO2 levels effect on agriculture
fertilizes, increases productivity
94
How has cereal production in different countries changed
developed countries have increased production by 5%, less developed declined by 10%
95
Effect of global warming on crop growth
Low temperature constrains on crop production will be lifted in many regions - but some crops require cold to initiate germination
96
pole-ward extension of northern boundaries by a 1 degree increase
1 degree increase in mean annual temperature will move northern boundaries 150-200km north.
97
What factors impact health
pollution, inadequate water supplies, poor soil
98
What is the main direct effect on health caused by climate change
heat stress in the extreme high temperatures that will be more frequent and widespread (St Louis, in 1998 - 5°C above average in August, 50% increase in death rate) * Paris, 2003 – 3,000 deaths )
99
Example of an increased spread of a disease due to climate change
tropical diseases - e.g., malaria by mosquitoes: optimal temperature range 15-32 with 50%-60% humidity IPCC predict malaria incidence could increase from 45% to 60% of world population by 2050
100
Human migration
* Bangladesh 15 million * China 30 million * India 30 million * Egypt 14 million * Others 60 million * TOTAL 150 million

Organisms And Their Environment (9 decks)

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