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Flashcards in Ecological principles Deck (133)
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1
Q

Define ecology

A

The scientific study of the interactions between organisms and their environment

2
Q

What is a critical factor of ecology?

A

Human activities

3
Q

What are two components of ecology?

A

Biotic

Abiotic

4
Q

What does biotic mean?

A

Living things

5
Q

What does abiotic mean?

A

Non-living things

6
Q

Where can pools of organic carbon be found?

A

In all living things

7
Q

What does the ecosystem concept study?

A

Pools and fluxes of matter and energy

8
Q

What are pools?

A

Quantities

9
Q

What are fluxes?

A

Flows

10
Q

What state are communities always in?

A

Flux

11
Q

What is a community?

A

“The community is an assemblage of species populations that occur together in space and time”

12
Q

What do ecosystems involve?

A

Communities and the physical environment

13
Q

Define biodiversity?

A

“The 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”

14
Q

What is an issue with biodiversity definitions?

A

“… such definitions end up saying merely that biodiversity is equivalent to ‘all of biology’”

15
Q

Why are there issues with the term ‘biodiversity’?

A

It is a relatively new term and has many meanings

16
Q

How can there be diversity within species?

A

Genotypic and phenotypic variation

17
Q

How can there be diversity between species?

A

Species diversity, equitability and disparity

18
Q

How is there diversity within ecosystems?

A

Biomes, landscapes, ecosystems, habitats, niches

19
Q

How does diversity vary?

A

With spatial scale

20
Q

What is alpha diversity?

A

This is biodiversity within a habitat

21
Q

What is beta diversity?

A

This is biodiversity between habitats

22
Q

What is gamma diversity?

A

This is biodiversity in landscapes or between habitats in landscapes (landscape scale)

23
Q

What is genotypic variation?

A

This is where there is a mutation in the genes between individuals of the same species or a different species

24
Q

What is phenotypic variation?

A

Differences in observable characteristics

25
Q

Define equitability

A

The extent of representation by equal numbers of individuals

26
Q

Why would life be impossible without species interactions?

A

Organisms depend on one another for energy, nutrients and habitats

27
Q

Why do actions in ecosystems have consequences?

A

Connections between organisms and the physical environment mean that events can have wide-ranging impacts

28
Q

What is meant by the idea that ‘everything goes somewhere’?

A

There is no ‘away’ into which waste materials disappear

29
Q

What does Commoner say is the first law of ecology?

A

Everything is related to everything else

30
Q

Why does genotypic and phenotypic variation occur?

A

Due to genes and the environment

31
Q

Explain why no population can increase its size forever?

A

There are limits to the growth and resource of every population

32
Q

Explain what is meant by the concept ‘there is no free lunch’

A

The energy available to an organism is finite; increasing inputs into one function results in losses for other functions

33
Q

What is meant by ecological carrying capacity?

A

The maximum sustainable population

34
Q

Explain what is meant by maximum sustainable population

A

This is the maximum population that can be sustained for a long amount of time without an ecosystem crash

35
Q

What is meant by the idea that species evolve?

A

Environmental change and competition for resources forces change in organisms

36
Q

Why is time important?

A

Ecosystems change over multiple timescales; what has happened in the past shapes what we see now

37
Q

What is important to look at when thinking about time?

A

Past and present conditions

38
Q

What is meant by ‘ecosystem function’?

A

This is what an ecosystem does, it underpins ecosystem services

39
Q

What are 6 functions that are part of ecosystems?

A
Photosynthesis
Autotrophic respiration
Decomposition
Soil respiration
Nutrient cycling 
Soil formation
40
Q

What causes soil to accumulate?

A

Weathering

41
Q

Why are ecosystem functions so important?

A

Humans can’t carry out the functions

42
Q

What is the name of the bacteria that invented the process of photosynthesis?

A

Cyanobacteria

43
Q

In which part of the plant does photosynthesis occur?

A

Chloroplasts

44
Q

What do the chloroplasts contain?

A

Chlorophyll

45
Q

What is the energy source for photosynthesis?

A

Light

46
Q

What is the energy source for chemosynthesis?

A

Inorganic compounds

47
Q

What is produced from primary production?

A

Complex C compounds from simple ingredients

48
Q

What are two processes that can occur in primary production?

A

Photosynthesis

Chemosynthesis

49
Q

Why is photosynthesis important?

A

It absorbs CO2

50
Q

What is the photosynthesis equation? symbols

A

6 CO2 + 12 H2O = C6H12O6 + 6 H2O + 6 O2

51
Q

What is the respiration equation? symbols

A

C6H12O6 + 6 H2O + 6 O2 = 6 CO2 + 12 H2O

52
Q

What is the word equation for photosynthesis?

A

carbon dioxide + water = glucose + water + oxygen

53
Q

What is the word equation for respiration?

A

glucose + water + oxygen = carbon dioxide + water

54
Q

What happens in photosynthesis?

A

Carbon is reduced to form complex organic commpounds

55
Q

What happens in respiration?

A

Carbon is oxidised to release energy

56
Q

What is the equation for ecosystem function?

A

GPP-R=NPP

57
Q

What is GPP?

A

Gross Primary Production
This is the total energy fixed
All the work that plants and bacteria do

58
Q

What is R?

A

This is respiration (energy lost through metabolic processes)

59
Q

What is NPP?

A

Net Primary Production
This is energy left over; often equated with biomass produced
Also crop yield

60
Q

What is NPP a balance of?

A

Photosynthesis and respiration

61
Q

Where is NPP highest?

A

In equatorial regions

62
Q

What does terrestrial NPP account for?

A

Two thirds of global total

63
Q

What is there a clear inequality in?

A

NPP

64
Q

What percentage of NPP do tropical forests account for?

A

21.9

65
Q

What percentage of NPP do tropical savannas account for?

A

14.9

66
Q

What percentage of NPP do temperate forests account for?

A

8.1

67
Q

What percentage of NPP do boreal forests account for?

A

2.6

68
Q

What percentage of NPP does Arctic tundra account for?

A

0.5

69
Q

Where is there considerable variation between in terms of NPP?

A

Variation between biomes

70
Q

Why is there spatial variations in terestrial NPP?

A

Insolation

Moisture availability

71
Q

Explain the spatial variation in marine NPP?

A

This pattern is quite different to that of terrestrial NPP

There is more NPP on continental fringes as there is lots of material from catchments

72
Q

What is the pattern in marine NPP associated with?

A

Nutrient supply

73
Q

What helps the nutrient supply?

A

Material from the catchment such as marine animals sink to the bottom and upwelling brings the nutrients up

74
Q

How much of the total NPP do oceans account for?

A

1/3

75
Q

What are autotrophs?

A

Primary producers

76
Q

What are heterotrophs?

A

Primary, secondary and tertiary consumers

77
Q

What do autotrophs do for energy?

A

They make their own

78
Q

What do heterotrophs do for energy?

A

They rely on others

79
Q

What do trophic levels show?

A

The feeding position of groups of organisms in an ecosystem

80
Q

What are food webs?

A

Conceptual models of trophic interactions

81
Q

Why are food webs complicated?

A

Because there is more than one food source

82
Q

What is an issue with complicated food webs?

A

It makes it harder to predict the impacts if there is a species loss/introduction

83
Q

Why is photosynthesis inefficient?

A

Not all light energy is utilised

84
Q

Why isn’t all of the light used in photosynthesis?

A

The light hits the wrong part of the plant
The light is deflected
The light is the wrong wavelength

85
Q

What happens between trophic levels?

A

Energy is lost

86
Q

What is required to sustain top predators?

A

A huge quantity of NPP

87
Q

On average, what percentage of energy in any trophic level is passed on to the next level?

A

10%

88
Q

What is HANPP?

A

Human Appropriation of NPP

89
Q

What percentage of the Earth’s bio-productive surface is dominated by people?

A

36%

90
Q

What percentage of terrestrial NPP have humans appropriated?

A

40%

91
Q

What is biogeochemical cycling?

A

The flows of chemical elements/compounds between living organisms and the physical environment

92
Q

What is biogeochemical cycling important for?

A

The nutrient supply and human well-being

93
Q

What is a major carbon pool?

A

The biosphere

94
Q

What happens to atmospheric CO2 during photosynthesis?

A

It is drawn-down

95
Q

What is a major player for the carbon cycle?

A

Humans

96
Q

What do humans have a big impact on in terms of the carbon cycle?

A

Atmospheric CO2 however, there is more CO2 in biomass than in the atmosphere

97
Q

Where is there a large reservoir of nitrogen?

A

There is a huge atmospheric reservoir of gaseous nitrogen (N2)

98
Q

How is nitrogen fixed?

A

By microbes

99
Q

What is meant by fixed nitrogen?

A

This means that it has been made into a nutrient for organisms

100
Q

How can humans affect the nitrogen cycle?

A

They can increase the amount of fixed carbon

101
Q

What is the P-cycle?

A

The phosphorus cycle

102
Q

What type of nutrient is phosphorus?

A

It is a mineral nutrient

Macronutrient

103
Q

What does the phosphorus cycle often limit?

A

Aquatic ecosystems

104
Q

Where is most phosphorus derived from?

A

Rock weathering

105
Q

What are most natural ecosystems deficient in?

A

Nitrogen

106
Q

Where does disturbance occur?

A

In all ecosystems

107
Q

Is nitrogen a limiting factor?

A

Yes

108
Q

Is it normal to experience disturbance in an ecosystem?

A

Yes

109
Q

Define ecosystem services?

A

“The suite of benefits that ecosystems provide to humanity”

110
Q

What does disturbance interrupt?

A

It disrupts ecosystem functions and the delivery of ecosystem services

111
Q

What keeps the system in equilibrium?

A

Feedback loops

112
Q

What does the ecosystem tend towards?

A

An equilibrium state

113
Q

By what type of feedback does self-regulation of ecosystems occur?

A

Negative feedbacks

114
Q

Define stable situation

A

The ecosystem goes back to its original state after a minor perturbation

115
Q

Define unstable situation

A

The ecosystem moves away from original state after a perturbation

116
Q

What do stable ecosystems resist?

A

They resist being pushed away from the equilibrium

117
Q

What is high engineering resilience?

A

This is a rapid return to original (equilibrium) state after a perturbation

118
Q

What does engineering resilience assume?

A

A single equilibrium

119
Q

What happens after an ecosystem reaches its threshold?

A

It goes into an alternative state, making it hard to get back to how it was

120
Q

Define threshold

A

“The amount of disturbance that can be sustained before an ecosystem crosses an ecological threshold”

121
Q

What does ecological resilience assume?

A

Multiple stable states

122
Q

What is hysteresis?

A

Ecosystem state is determined by history and current conditions
Abrupt ecological change may be very hard to reverse

123
Q

What percentage of the Earth’s land surface do cultivated systems cover?

A

25%

124
Q

What percentage of land has been transformed or degraded?

A

39-50%

125
Q

How much water is in reservoirs compared to natural rivers?

A

3-6 times as much water in reservoirs as in natural rivers

126
Q

How much run-off water do humans use?

A

They use more than half of the runoff water that is fresh and reasonably accessible

127
Q

How do humans disturb the water cycle?

A

Humans appropriate the majority of fresh, accessible water

Severe degradation of coastal ecosystems

128
Q

By how much have atmospheric carbon concentrations increased since the pre-industrial era?

A

By 30%

129
Q

Which two cycles do humans dominate?

A

N and P cycles with humans producing as much of these as all natural pathways combined

130
Q

What are human activities increasing?

A

Extinction rates

131
Q

What does loss of diversity impair?

A

Ecosystem function

132
Q

What is the anthropocene?

A

This is a proposed geological epoch characterised by significant human impact on the Earth’s geology and ecosystems

133
Q

What is the idea behind planetary boundaries?

A

There are global limits to exploitation