Ecology and Conservation Flashcards
1
Q
Autotrophs are…
A
…organisms that utilise an inorganic energy source (i.e. through photosynthesis/chemosynthesis)
2
Q
Heterotrophs are…
A
…organisms that utilise an organic energy source (i.e. through consuming other organisms)
3
Q
Unitary organisms have…
A
…predictable or determinate development. (e.g. animal develop a fixed number of legs).
4
Q
Modular organisms have…
A
…unpredictable or indeterminate development (e.g. trees do not develop a fixed number of branches).
5
Q
What are the 3 photosynthetic pathways?
A
C3, C4, CAM
6
Q
What is the C:N ratio of plant tissue?
What impact does this have on herbivores?
A
40:1
Herbivores excrete excess carbon as methane.
7
Q
What is the C:N ratio of animal tissue?
What impact does this have on carnivores?
A
10:1
Carnivores excrete excess nitrogen as uric acid.
8
Q
A ‘population’ is…
A
a group of individuals of a single species, inhabiting a specific area and capable of interbreeding.
9
Q
Give 3 applications of population counts…
A
- Judging the effectiveness of conservation programmes.
- Judging the effectiveness of pest control or disease erradication programmes.
- Sustainably managing resources such as fish or game.
10
Q
An organism’s fundamental niche is…
A
…the widest range of environmental conditions the organism can potentially inhabit, in the absence of competition/predation.
11
Q
An organisms realised niche is…
A
…the narrower range of conditions the organism is practically restricted to by competition/predation.
12
Q
Abundance is…
A
…the total number of individuals (or total biomass) within a defined area of any size.
13
Q
Density is…
A
…the number of individuals (or amount of biomass) per unit of area.
14
Q
Density and adult body size display what kind of relationship?
A
Negative correlation.
15
Q
Extirpation is…
A
…the loss of the last member of a given population (i.e. a local phenomenon).
16
Q
Extinction is…
A
…the loss of the last member of a species (i.e. a global phenomenon).
17
Q
Iteroparous refers to…
A
…animals with a lifecycle characterised by multiple reproductive episodes.
18
Q
Semelparous refers to…
A
…animals with a lifecycle characterised by a single reproductive episode.
19
Q
Polycarpic refers to…
A
…plants with a lifecycle characterised by multiple reproductive episodes.
20
Q
Monocarpic refers to….
A
…plants with a lifecycle characterised by a single reproductive episode.
21
Q
Change in population is given by… (formula)
A
P_now = P_then + Births - Deaths + Immigration - Emmigration
22
Q
Cohort life tables show…
They are…
A
…records from birth to death for all individuals born during the same timeframe.
…difficult to collect, but easy to interpret.
23
Q
Static life tables show…
They are…
A
…a snapshot of population structure across age groups at a single point in time.
…easy to collect, but difficult to interpret.
24
Q
In a type 1 survivorship curve…
A
…risk of mortality increases with age.
25
In a type 2 survivorship curve...
...risk of mortality is constant through life.
26
In a type 3 survivorship curve...
...risk of mortality decreases with age.
27
Net reproductive rate (R0) is given by... (formula)
R0 = Σ lx mx
Where: lx is the proportion of the population surviving to day x.
And: mx is the average number of births produced by each individual at each age interval.
28
Net reproductive rate is...
...the average number of offspring produced in a lifetime by individuals within a population.
29
A metapopulation is...
...a group of subpopulations occupying a fragmented habitat, connected by the exchange of individuals (migration).
30
Source patches are...
...subpopulations where the number of births exceeds the number of deaths.
31
Sink patches are...
...subpopulations where the number of deaths exceeds the number of births (i.e. R0 < 1).
32
What type of growth models overlapping generations?
Exponential growth.
33
What type of growth models non-overlapping generations?
Geometric growth.
34
Ovuilparity is...
...when females release oocytes for external fertilisation. Nutrition is lecithotrophic.
35
True oviparity is...
...where fertilisation occurs internally, and the female releases eggs containing zygotes to develop outside of her body. Nutrition is lecithotrophic.
36
Ovoviviparity is...
...where embryos develop in eggs retained the female, resulting in live birth. Nutrition is lecithotrophic.
37
Viviparity is...
...where embryos develop inside the uterus of the female, resulting in live birth. Nutrition is matrotrophic.
38
Lecithotrophic refers to...
...species where embryos develop using nutrients stored in the egg.
39
Matrotrophic refers to...
...species where embryos develop using nutrients supplied throughout gestation by the mother.
40
What are the trade-offs of delaying reproduction?
Delaying reproduction allows more energy to be dedicated to growth (i.e. to grow larger/develop faster) but increases the risk of not surviving to reach reproductive maturity.
41
Early breeding is selected for by...
...low chance of individual survival.
42
Low chance of individual survival selects for...
...earlier breeding.
43
High chance of individual survival selects for...
...later breeding.
44
Late breeding is selected for by...
...high chance of individual survival.
45
Gonodosomatic index is...
It used as a proxy for...
It is negatively correlated with...
...gonad mass as a proportion of total body mass.
...reproductive effort.
...adult:juvenile survival ratio.
46
In r-selected species, intrinsic rate of increase (r_max) is...
...high.
47
In k-selected species, intrinsic rate of increase (r_max) is...
...low.
48
r-selection is favoured by...
...unpredictable environments.
49
k-selection is favoured by...
...predictable environments.
50
In r-selected species, development is...
...rapid.
51
In k-selected species, development is...
...gradual.
52
In r-selected species, body size is...
...smaller.
53
In k-selected species, body size is...
...typically larger.
54
In r-selected species, reproduction occurs...
...earlier
55
In k-selected species, reproduction occurs...
...later.
56
In r-selected species, reproduction tends to be...
...semelparous/monocarpic.
57
In k-selected species, reproductive strategy tends to be...
...iteroparous/polycarpic.
58
In r-selected species, offspring are...
...smaller and more numerous.
59
in k-selected species, offspring are...
...larger and less numerous.
60
Which life history strategy promotes competative ability?
k-selection.
61
Which two key variables exert selective pressure on plants?
Stress - constraints on the production of plant biomass.
| Disturbance - the destruction of plant biomass.
62
Plants exploiting high disturbance/low stress environments are referred to as...
...ruderals.
63
Plants exploiting low disturbance/high stress environments are referred to as...
...stress-tolerant.
64
Plants exploiting low distrbance/low stress environments are referred to as...
...competative.
65
Give 5 typical characteristics of ruderals.
Ruderals tend to be smaller, faster growing, monocarpic, reproduce early, have highly dispersed seeds.
66
Give 4 typical characteristics of stress-tolerants.
Stress-tolerants tend to be slower growing, evergreen, well defended, highly specialised
67
Give 3 characteristics of Competatives:
Competatives tend to be rapid growing, have later maturation, have larger seeds.
68
Salt tolerant plants are called...
...halophytes.
69
Parental care is associated with which life history strategy?
k-selection.
70
Parent-offspring conflict results from...
A parental optimum for additional reproductive episodes, and an offspring optimum for continued support.
71
Competition reduces the fitness of...
...both parties.
72
Niche partitioning occurs when...
...two species fundemental niches overlap, but each species is competatively excluded from a different part of the overlap, creating non-overlapping realised niches.
73
The competitive exclusion principle states that...
...two species with identical niches cannot coexist indefinitely.
74
Intraspecific competition leads to...
...increased mortality among conspecifics.
75
The self-thinning rule predicts that...
...plants decrease in population density as total biomass increases.
76
What are the two types of competition?
Interference (e.g. direct aggression)
| Exploitation (e.g. consumption of resources)
77
Competition occurs in the presence of...
...a limiting resource.
78
What effect does interspecifc competition have on carrying capacity?
Interspecific competition lowers the carrying capacity for both species.
79
Character displacement occurs when...
...competition between two species with overlapping niches creates a selection pressure to minimising their similarities and accentuating their differences, thereby reducing niche overlap.
80
A 'guild' is...
...a group of species utilising the same resource.
81
Invasive species are...
...non-native species that displace or exclude native species.
82
A population becomes naturalised when...
...it is capable of sustaining itself through reproduction, rather than continuous immigration.
83
What effect do predatory interactions have on fitness?
Predatory interactions enhance the fitness of one species (the predator) at the expense of another (the prey).
84
True predators...
...kill and consume their prey.
85
Grazers...
...partially consume and rarely kill their prey.
86
Parasites...
...live on an individual host's tissue, partially consuming but rarely killing their hosts.
87
Parasitoids...
...live on an individual host's tissue, consuming and eventually killing the hosts.
88
Organisms with one prey/host species are described as...
...monophagous.
89
Organisms with a few prey/host species are described as...
...oligophagous.
90
Organisms with many prey/host species are described as...
...polyphagous.
91
Foraging efficiency is given by the equation...
Efficiency = Reward Energy / (Handling time + Search time)
92
According to optimal foraging theory, high handling times (h) promote what foraging strategies?
Specialist.
93
According to optimal foraging theory, high search times (s) promote what foraging strategies?
Generalist.
94
When is it beneficial to consume alternative, less profitable, prey?
When Ei/hi > E/(s+h)
When the Energy / Handling time of the alternative prey is greater than the Energy / (Search time + Handling time) of the prefered prey.
95
Phase shift refers to...
...a delay between two waves with the same frequency.
96
As predator numbers increase prey is supressed, reducing predator carrying capacity.
As predator numbers decrease prey is released, increasing predator carrying capacity. This creates a...
...dynamic equilibrium between abundance of predators and prey.
97
If we graph the abundances of predators and their prey, we would expect to see...
...phase shifted synchronous oscilations.
98
Gause's experiments with paramecium demonstrated that for a prey population to persist, they may require...
...a refuge, to prevent them being hunted to extirpation.
99
Gause's experiments with paramecium demonstrated that for a predator population to persist, they require...
...immigration of prey from a refuge, supporting their trophic requirements while preventing extirpation through overexploitation of prey.
100
Type 1 functional response is when...
...consumption increases linearly with prey density, before leveling off at maximum rate.
101
Type 2 fuctional response is when...
...consumption increases with food density at a decreasing rate, before levelling off at maximum rate.
102
Type 3 functional response is when...
...consumption increases with food density at an increasing rate at lower densities, but at a decreasing rate at higher densities, creating a sigmoid (s-shaped) curve.
103
Functional response curves graph which two variables?
x axis = Prey density.
| y axis = Food consumption per unit time.
104
What produces a type 1 functional response curve?
Type 1 responses occur when prey has very low handling times.
105
What produces a type 2 functional response curve?
Type 2 responses occur because at low prey densities feeding rate is limited by search time, while at high prey densities feeding rate becomes limited by handling time.
106
What produces a type 3 functional response curve?
Type 3 responses may occur because:
Consumers exhibit a disproportionate preference for more abundant prey. When prey density is low, it is consumed in lower proportion than predicted by its availability; when prey density is high, it is consumed in greater proportion than predicted by its availability.
One potential reason for this is because:
At low prey densities, consumers encounter prey infrequently and therefore have less success in their predation attempts. As prey density rises, consumers have more opportunities to learn successful predation strategies and consumption increases.
107
All functional response curves level off because...
...at very high levels of prey density, the energy intake of an organism becomes limited by internal, rather than external, constraints (it has reached it's maximum rate).
108
What does it mean if R0 is <1?
Reproduction is occuring at below replacement levels, and the population will decrease.
109
What does it mean if R0 is >1?
Reproduction is occuring at above replacement levels, and the population will increase.
110
Commensalism is when...
...a relationship has a beneficial impact on individuals of one species and a neutral impact on individuals of the other.
111
Mutualism is when...
...a relationship increases the fitness of individuals from both species involved.
112
Symbiosis is when...
...individuals of two species are involved in a close and persistant biological interaction.
113
Amensalism is when...
...a relationship has a beneficial impact on individuals of one species and a negative impact on individuals of another.
114
A relationship that has a beneficial impact on individuals of one species and a neutral impact on individuals of the other is called a...
...commensalism.
115
A relationship that has a beneficial impact on individuals of both species involved is called a...
...mutualism.
116
A relationship that has a beneficial impact on individuals of one species and a negative impact on individuals of another is called a...
...amensalism.
117
Relationships that are necessary for survival, growth or reproduction are termed...
...obligate.
118
Relationships that improve fitness but are not necessary for survival, growth or reproduction are termed...
...facultative.
119
Red flowers are typically pollinated by which order?
Lepidoptera.
120
Which insect order does not pollinate red flowers, and why?
The visual spectrum of the hymenoptera does not include wavelengths associated with red light.
121
What is the cause of coral bleaching?
Corals expel Zooxanthellae (photosynthetic protist symbionts) in response to increased temperatures. Persistant heat causes the corals to starve.
122
C3 is catalysed by...
...rubisco.
123
C4 is catalysed by...
...PEP carboxylase.
124
CAM is catalysed by...
...PEP carboxylase.
125
C3 is characterised by...
...extensive photorespiration and water loss.
126
C4 is characterised by...
...moderate photorespiration and water loss.
127
CAM is characterised by....
...minimal photorespiration and water loss.
128
C3 photosynthesis occurs...
...entirely in the mesophyll.
129
C4 photosyntheis occurs...
...in the mesophyll (organic acid cycle) and in the bundle sheath (Calvin cycle).
130
CAM photosynthesis occurs...
...entirely in the mesophyll, but is temporally seperated: The organic acid cycle occurs during the night while the Calvin cycle occurs during the day.
131
PAR stands for...
...photosynthetically active radiation.
132
CAM stands for...
...Crassulacean acid metabolism.
133
Rate of primary production is...
...the amount of energy fixed per unit time per unit area.
134
Gross primary production is...
...the total amount of energy fixed by autotrophs within an ecosystem.
135
Net primary production is...
...the amount of energy left after the autotroph's immediate metabolic needs are met.
136
What is the relationship between NPP and actual evapotranspiration?
Near linear.
137
What is actual evapotranspiration?
| What affects actual evapotranspiration?
Actual evapotranspiration = Evaporation + Transpiration.
| Actual evapotranspiration is dependent on temperature and humidity.
138
What is the relationship between species richness and NPP?
Species richness is positively correlated with NPP.
139
What is the relationship between fertility and NPP?
Fertility (nutrient availability) of a habitat is positively correlated with NPP.
140
Shallow seas are [more/less] productive than open ocean? Why?
More productive, due to continental run-off.
141
Open ocean accounts for what percentage of global NPP?
~25%
142
Which habitats have the highest average NPP?
Algal beds and coral reefs
143
What is primary production?
The fixation of energy by autotrophs.
144
How can heterotrophs influence the rate of NPP?
By reducing autotroph biomass. (e.g. locust swarms)
145
What percentage of solar radiation is fixed as GPP?
2.2%
146
What percentage of solar radiation is NPP?
1%
147
What is ecological efficiency?
Ecological efficiency is the percentage of energy transfered between trophic levels. (~5-20% per level)
148
What limits the total number of trophic levels within an ecosystem?
Ecological efficiency (the percenatge of energy transfered between trophic levels).
149
What are the principle limits to primary production in terrestrial environments?
Insolation, temperature and moisture.
150
What is the principle limit to primary production in aquatic environments?
Nutrient availability.
151
When prey aggregate in high densities to reduce the risk of individual predation, this is know...
...predator satiation defence.
152
The protein and oil rich structures used by acacia trees to reward ants are called...
...Beltian bodies.
153
The protein and oil rich structures used by many plants to encouage the dispersal of seeds by ants are called...
...Elaiosomes.
154
Mutualisms are likely to evolve when...
...the benefits to be gained are predictable and stable.
155
Evapotranspiration rates are highest in...
...warm, wet climates.
156
The amount of energy lost at each trophic level is approximately...
...90%.
157
Removal of a keystone species leads to...
...the collapse of a community structure.
158
Top down control refers to ...
...the influence that organisms at higher trophic levels have on community structure at lower trophic levels.
159
Bottom up control refers to...
...the influence that organisms at lower trophic levels have on community structure at higher trophic levels.
160
In a species-area relationship...
...the number of species in an area of habitat increases as the area of that habitat increases.
161
Which taxa has the most named species?
The invertebrates.
162
What factor is generally accepeted as posing the greatest threat to the largest number of species?
Habitat loss.
163
Nutrients are cycled between...
...pools or compartments: the atmosphere, land, oceans and freshwater.
164
Transfer of nutrients between compartments is called...
...flux.
165
What is the major reservoir of phosphorus?
Phosphorus is slowly released from the Earth's crust by the weathering of rocks.
166
Where is the major phosphorous sink?
Oceans sediment is a major phosphorous sink.
167
A global phosphorus shortage is predicted by...
...2030.
168
Nitrogen makes up what percentage of the atmosphere?
78%
169
Nitrogen fixation occurs through the action of...
| 4 things
Lightening, cyanobacteria, rhyzobium, actinomycetes.
170
Nitrogen fixation is...
...the reduction of N2 to (NH3).
171
Nitrogen fixation is achieved artifically through...
...the Haber-Bosch process.
172
Denitrification is...
...the release of N2 by bacteria/fungi during decomposition.
173
Excessive nitrogenous run-off may result in...
| 3 things
...eutrophication, algal blooms, and hypoxic dead zones.
174
What are the 3 major reservoirs of carbon?
Fossil fuels.
Carbonate minerals in rocks and marine sediment.
Carbon dissolved in the oceans as carbonic acid.
175
Give 3 anthropogenic nitrogen fluxes:
Fertiliser produced by the Haber-Bosch process.
Leguminous cropping to improve soils.
Combustion of fossil fuels, producing nitrates/nitrites.
176
Give 5 anthropogenic carbon fluxes:
```
Deforestation.
Combustion of fossil fuels/biomass.
Cutting peat for fuel or compost.
Thermal decomposition of CaCO3 during cement manufacture.
Excessive deep-ploughing of soils.
```
177
The speed of nutrient cycling is determined by...
...net primary production.
178
Tropical rainforests are nutrient rich or nutrient poor?
Nutrient poor.
179
When nutrients are cycled quickly...
...there is litte opportunity for them to be lost from the system.
180
The speed of nutrient cycling in tropical rainforests is _ occuring on a _ year cycle.
Fast, occuring on a ~0.4 year cycle.
181
The speed of nutrient cycling in temperate forests is _ occuring on a _ year cycle.
moderate occuring on a ~4 year cycle.
182
The speed of nutrient cycling in boreal forests is _ , occuring on a _ year cycle.
slow, occuring on a ~50 year cycle.
183
Decomposition occurs more rapidly where...
...temperature and actual evapotranspiration are higher.
184
Soil fertility and rate of decomposition are...
...positively correlated.
185
The Hubbard Brook experiment showed that nitrogen concentration in the run-off from a deforested watershed was...
...60x greater than a control.
186
Tropical forests have what percentage of their total nutrients contained in the soil?
10%
187
A disturbance is...
...a process or event that drastically alters the composition of an ecosystem.
188
A process or event that drastically alters the composition of an ecosystem is called a...
...disturbance.
189
Gradual change in a biotic community is called...
...succession.
190
Primary succession occurs...
...on new substrates, devoid of vegetation (e.g. larva flows, retreating glaciers).
191
Secondary succession occurs...
...after a disturbance (e.g. storm, forest fire, felling).
192
Describe the rate at which species richness changes during succession...
Species richness increases rapidly in the early stages of succession but slows as vegetation approachs climax.
193
The absence of change in community structure is called...
...stability.
194
The ability to maintain community structure through a disturbance is called...
...resistance.
195
The ability for a community to recover after a disturbance is called...
...resilience.
196
What 4 things increase during sucession?
Biomass
Primary production
Species richness
Nutrient retention
197
Food webs show...
...a summary of the feeding relationships within a community.
198
Food chains show...
...a linear sequence of direct feeding interactions.
199
Give 4 limitations of food webs:
Likely to be an incomplete depiction of community.
Limit their focus to feeding relationships, neglecting other interactions.
Do not account for heterogenity within trophic levels (e.g. different vulnerability to predators)
Omnivores/generalists may be hard to assign to a particular trophic level.
200
Keystone species are those which...
...exert a disproportionate effect on commmunity structre relative to their biomass.
201
What effect do keystone species have on species diversity?
Keystone species increase species diversity by keeping prey below carrying capacity, thereby preventing competative exclusion.
202
More diverse food webs show...
...proportionally higher species richness.
203
At what trophic level do keystone species occur?
Keystone species may occur at any trophic level.
204
Foundation species are those which...
...significantly influence community structure by virtue of high biomass.
205
Umbrella species are those which...
...have been selected as conservation targets on the basis that promoting this species will indirectly benefit many others (often because of shared ecological requirements).
206
Flagship species are those which...
...have been selected as conservation targets on the basis that they will generate the most public engagement (often because they are particularly charasmatic, or have some significance to national identity).
207
Biological diversity can refer to...
| 3 things
Diversity of habitats
Diversity of species (species richness)
Genetic diversity with species (or within a population)
208
Abundance is...
...the number of individuals of a given species within a defined area.
209
Total abundance is...
...the number of individuals of all species within a defined area.
210
What is the relationship between species richness and island area?
Species richness increases logarithmically with island area.
211
Why do larger areas contain more species?
Larger areas means greater diversity of habitats which means increases species richness.
212
What is the relationship between rate of extinction and species richness?
Why? (3 reasons)
Rate of extinction increases with increasing species richness because:
More species = more potential extinctions.
More species = smaller populations of each.
More species = more opportunities of competative exclusion.
213
What is the relationship between rate of immigration (of novel species) and species richenss?
Why? (1 reason)
Rate of immigration falls as species richness increases because new arivals have a greater liklihood of already being present.
214
Remote islands may have far higher species richness than predicted by the MacArthur-Wilson model of island biogeography because of...
...adaptive radiation.
215
Macroecology is...
...the study of distribution and abundance at large spacial scales.
216
What 4 abiotic factors influence geographic patterns in species richness?
Latitude
Altitude/depth
Age of ecosystem
Isolation
217
What 3 biotic factors influence geographic patterns in species richness?
Interspecific interactions (predation, competition, etc)
Succession
Species-generated heterogeneity
218
For any given limiting factor, species richness is determined by...
(4 things)
Range
Niche bredth
Niche overlap
Saturation
219
Alpha diversity is...
...species richness within a habitat.
220
Beta diversity is...
...species richness between habitats - the ratio between regional and local diversity.
221
Gamma diversity is...
...species richness across habitats.
222
The relationship between alpha, beta and gamma diversity is given by the formula:
```
B = Y/a
Beta = Gamma / Alpha
```
223
Extent of occurence is given by...
...the area within the boundary of a minimum convex polygon encompassing all known sites of occurrence.
224
Area of occupancy is given by...
...the total number of occupied grid squares.
225
Give 5 reasons for the latitudinal species richness gradient:
1) Time since pertubation - Temperate communities have more recently been disrupted by glaciation.
2) Productivity - Insolation is greatest and most constant in the tropics, increasing primary production and therefore species richness.
3) Climate stability - More stable temperatures in the tropics promote a greater number of more narrowly specialised species.
4) Environmental heterogeneity - Greater variety of habitats means more potential niches.
5) Area - Tropics are significantly larger than other regions.
226
How many biodiversity hotspots exist?
35.
227
What are the criteria for biodiversity hotspots?
More than 1500 endemic plant species in a habitat reduced to less than 30% natural vegetation.
228
Biodiversity hotspots represent what percentage of plant and animal species?
~50%
229
Biodiversity hotspots make up what percentage of the Earth's surface?
2.3%
230
What is the IUCN criteria for a critically endangered species?
50% chance of extinction within 10 years or 3 generations.
231
What is the IUCN criteria for a endangered species?
20% chance of extinction within 20 years.
232
What is the IUCN criteria for a vulnerable species?
10% chance of extinction within 100 years.
233
Give 3 anthropogenic drivers of biodiversity loss:
Overexploitation.
Habitat disruption (destruction, degredation or disturbance).
Introduction of invasive species.
234
What percentage of terrestrial areas are currently protected?
17%
235
What percentage of national waters are currently protected?
10%
236
Give 3 criteria that might be used to select conservation targets:
Rarity or vulnerability.
Evolutionary distinctiveness.
Utility.
237
Give 3 reasons to proritise less threatened habitats in conservation:
It's easier (lower vulnerability).
They are likely to be the most pristine.
They have the least impact on people/least opposition.
238
An extinction vortex is when...
...declining numbers fragment populations, increase genetic drift and create inbreeding depression, creating a feedback loop of increased sensitvity to disruption.
239
The abililty of an animal to avoid detection by predators is called...
...crypsis.
240
The signalling by an animal that it will be unprofitable to attack/predate is called...
...aposemetism.
241
At large spacial scales, individuals within a population tend to be...
...clumped together.
242
Geometric rate of increase (lambda) is given by...
...population now / population then.
