Ecological principles Flashcards
(133 cards)
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
Define equitability
The extent of representation by equal numbers of individuals
26
Why would life be impossible without species interactions?
Organisms depend on one another for energy, nutrients and habitats
27
Why do actions in ecosystems have consequences?
Connections between organisms and the physical environment mean that events can have wide-ranging impacts
28
What is meant by the idea that 'everything goes somewhere'?
There is no 'away' into which waste materials disappear
29
What does Commoner say is the first law of ecology?
Everything is related to everything else
30
Why does genotypic and phenotypic variation occur?
Due to genes and the environment
31
Explain why no population can increase its size forever?
There are limits to the growth and resource of every population
32
Explain what is meant by the concept 'there is no free lunch'
The energy available to an organism is finite; increasing inputs into one function results in losses for other functions
33
What is meant by ecological carrying capacity?
The maximum sustainable population
34
Explain what is meant by maximum sustainable population
This is the maximum population that can be sustained for a long amount of time without an ecosystem crash
35
What is meant by the idea that species evolve?
Environmental change and competition for resources forces change in organisms
36
Why is time important?
Ecosystems change over multiple timescales; what has happened in the past shapes what we see now
37
What is important to look at when thinking about time?
Past and present conditions
38
What is meant by 'ecosystem function'?
This is what an ecosystem does, it underpins ecosystem services
39
What are 6 functions that are part of ecosystems?
```
Photosynthesis
Autotrophic respiration
Decomposition
Soil respiration
Nutrient cycling
Soil formation
```
40
What causes soil to accumulate?
Weathering
41
Why are ecosystem functions so important?
Humans can't carry out the functions
42
What is the name of the bacteria that invented the process of photosynthesis?
Cyanobacteria
43
In which part of the plant does photosynthesis occur?
Chloroplasts
44
What do the chloroplasts contain?
Chlorophyll
45
What is the energy source for photosynthesis?
Light
46
What is the energy source for chemosynthesis?
Inorganic compounds
47
What is produced from primary production?
Complex C compounds from simple ingredients
48
What are two processes that can occur in primary production?
Photosynthesis
| Chemosynthesis
49
Why is photosynthesis important?
It absorbs CO2
50
What is the photosynthesis equation? symbols
6 CO2 + 12 H2O = C6H12O6 + 6 H2O + 6 O2
51
What is the respiration equation? symbols
C6H12O6 + 6 H2O + 6 O2 = 6 CO2 + 12 H2O
52
What is the word equation for photosynthesis?
carbon dioxide + water = glucose + water + oxygen
53
What is the word equation for respiration?
glucose + water + oxygen = carbon dioxide + water
54
What happens in photosynthesis?
Carbon is reduced to form complex organic commpounds
55
What happens in respiration?
Carbon is oxidised to release energy
56
What is the equation for ecosystem function?
GPP-R=NPP
57
What is GPP?
Gross Primary Production
This is the total energy fixed
All the work that plants and bacteria do
58
What is R?
This is respiration (energy lost through metabolic processes)
59
What is NPP?
Net Primary Production
This is energy left over; often equated with biomass produced
Also crop yield
60
What is NPP a balance of?
Photosynthesis and respiration
61
Where is NPP highest?
In equatorial regions
62
What does terrestrial NPP account for?
Two thirds of global total
63
What is there a clear inequality in?
NPP
64
What percentage of NPP do tropical forests account for?
21.9
65
What percentage of NPP do tropical savannas account for?
14.9
66
What percentage of NPP do temperate forests account for?
8.1
67
What percentage of NPP do boreal forests account for?
2.6
68
What percentage of NPP does Arctic tundra account for?
0.5
69
Where is there considerable variation between in terms of NPP?
Variation between biomes
70
Why is there spatial variations in terestrial NPP?
Insolation
| Moisture availability
71
Explain the spatial variation in marine NPP?
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
What is the pattern in marine NPP associated with?
Nutrient supply
73
What helps the nutrient supply?
Material from the catchment such as marine animals sink to the bottom and upwelling brings the nutrients up
74
How much of the total NPP do oceans account for?
1/3
75
What are autotrophs?
Primary producers
76
What are heterotrophs?
Primary, secondary and tertiary consumers
77
What do autotrophs do for energy?
They make their own
78
What do heterotrophs do for energy?
They rely on others
79
What do trophic levels show?
The feeding position of groups of organisms in an ecosystem
80
What are food webs?
Conceptual models of trophic interactions
81
Why are food webs complicated?
Because there is more than one food source
82
What is an issue with complicated food webs?
It makes it harder to predict the impacts if there is a species loss/introduction
83
Why is photosynthesis inefficient?
Not all light energy is utilised
84
Why isn't all of the light used in photosynthesis?
The light hits the wrong part of the plant
The light is deflected
The light is the wrong wavelength
85
What happens between trophic levels?
Energy is lost
86
What is required to sustain top predators?
A huge quantity of NPP
87
On average, what percentage of energy in any trophic level is passed on to the next level?
10%
88
What is HANPP?
Human Appropriation of NPP
89
What percentage of the Earth's bio-productive surface is dominated by people?
36%
90
What percentage of terrestrial NPP have humans appropriated?
40%
91
What is biogeochemical cycling?
The flows of chemical elements/compounds between living organisms and the physical environment
92
What is biogeochemical cycling important for?
The nutrient supply and human well-being
93
What is a major carbon pool?
The biosphere
94
What happens to atmospheric CO2 during photosynthesis?
It is drawn-down
95
What is a major player for the carbon cycle?
Humans
96
What do humans have a big impact on in terms of the carbon cycle?
Atmospheric CO2 however, there is more CO2 in biomass than in the atmosphere
97
Where is there a large reservoir of nitrogen?
There is a huge atmospheric reservoir of gaseous nitrogen (N2)
98
How is nitrogen fixed?
By microbes
99
What is meant by fixed nitrogen?
This means that it has been made into a nutrient for organisms
100
How can humans affect the nitrogen cycle?
They can increase the amount of fixed carbon
101
What is the P-cycle?
The phosphorus cycle
102
What type of nutrient is phosphorus?
It is a mineral nutrient
| Macronutrient
103
What does the phosphorus cycle often limit?
Aquatic ecosystems
104
Where is most phosphorus derived from?
Rock weathering
105
What are most natural ecosystems deficient in?
Nitrogen
106
Where does disturbance occur?
In all ecosystems
107
Is nitrogen a limiting factor?
Yes
108
Is it normal to experience disturbance in an ecosystem?
Yes
109
Define ecosystem services?
"The suite of benefits that ecosystems provide to humanity"
110
What does disturbance interrupt?
It disrupts ecosystem functions and the delivery of ecosystem services
111
What keeps the system in equilibrium?
Feedback loops
112
What does the ecosystem tend towards?
An equilibrium state
113
By what type of feedback does self-regulation of ecosystems occur?
Negative feedbacks
114
Define stable situation
The ecosystem goes back to its original state after a minor perturbation
115
Define unstable situation
The ecosystem moves away from original state after a perturbation
116
What do stable ecosystems resist?
They resist being pushed away from the equilibrium
117
What is high engineering resilience?
This is a rapid return to original (equilibrium) state after a perturbation
118
What does engineering resilience assume?
A single equilibrium
119
What happens after an ecosystem reaches its threshold?
It goes into an alternative state, making it hard to get back to how it was
120
Define threshold
"The amount of disturbance that can be sustained before an ecosystem crosses an ecological threshold"
121
What does ecological resilience assume?
Multiple stable states
122
What is hysteresis?
Ecosystem state is determined by history and current conditions
Abrupt ecological change may be very hard to reverse
123
What percentage of the Earth's land surface do cultivated systems cover?
25%
124
What percentage of land has been transformed or degraded?
39-50%
125
How much water is in reservoirs compared to natural rivers?
3-6 times as much water in reservoirs as in natural rivers
126
How much run-off water do humans use?
They use more than half of the runoff water that is fresh and reasonably accessible
127
How do humans disturb the water cycle?
Humans appropriate the majority of fresh, accessible water
| Severe degradation of coastal ecosystems
128
By how much have atmospheric carbon concentrations increased since the pre-industrial era?
By 30%
129
Which two cycles do humans dominate?
N and P cycles with humans producing as much of these as all natural pathways combined
130
What are human activities increasing?
Extinction rates
131
What does loss of diversity impair?
Ecosystem function
132
What is the anthropocene?
This is a proposed geological epoch characterised by significant human impact on the Earth's geology and ecosystems
133
What is the idea behind planetary boundaries?
There are global limits to exploitation
