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BIOL327 - Pop/Comm Ecology > Final Exam > Flashcards

Final Exam Flashcards

(144 cards)

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1
Q

What is Hierarchical Organisation (From Biggest to Smallest) in Ecology?

A

Biosphere –> Ecosystems –> Communities –> Populations –> Individuals –> Organ systems

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2
Q

What is carrying capacity?

A

Largest number of individuals (of a population) that a environment can support

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3
Q

What does the inductive method involve in creating hypotheses?

A

Created by Francis Bacon, involves making a series of statements leading to a logical inference (from specific to general) - Suggests what is likely to be true

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4
Q

What is the Hypothetico-deductive method?

A

Starts with more than one hypothesis, and continues through to uncover data that discriminates between these hypotheses, seeking to falsify incorrect hypotheses (continually improving on them with new tests).

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5
Q

What does the deductive method involve in creating hypotheses?

A

Created by Aristotle, it involves making a series of premises leading to a logical conclusion (general to specific) - Depends on the validity of the premises.

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6
Q

What is induction via model selection?

A

Sets up several working hypotheses or alternative plausible models. You accept the best working model (that fits the data the best)

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7
Q

What is systematic sampling? And what are its limitations?

A

Sample at regular intervals (e.g. every 5m, evenly spaced) - Limitations: Not quite possible to sample an entire habitat, and can lead to bias due to environmental variation.

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8
Q

What is simple random sampling? And what are its limitations?

A

The least biased sampling method in which each member of the population has an equal probability of being included in the sample. Its limitations are that certain environments or individuals may be left out all together (some areas may be disproportionately sampled).

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9
Q

What is stratified random sampling? And what are its limitations?

A

Involves dividing the total area into different strata, then sampling these areas at random intervals. However, more time and money required to classify the environment.

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10
Q

What is haphazard sampling? And what are its limitations?

A

Selecting subjects in a haphazard manner, usually on the basis of availability, and not with regard to having a representative sample of the population. Not always possible in a real field situation.

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11
Q

What is pseudoreplication?

A

The error that occurs when samples are not independent, but are treated as though they are. E.g. one treated and untreated site are taken, however environmental variation (or any other variation) is not considered between sites. More than one treated site is required.

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12
Q

What is standard error?

A

The standard deviation of a sampling distribution, worked out by dividing the standard deviation by the square root of the number of samples.

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13
Q

What is a confidence interval?

A

The range of values within which a population parameter is estimated to lie

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14
Q

What does lower variance indicate?

A

Indicates values are closer to the mean (less spread out)

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15
Q

What does higher variance indicate?

A

Indicates values are farther from the mean, therefore the higher the uncertainty of the outcome.

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16
Q

What are 3 factors that influence our ability to detect effects?

A
  1. Sample size - number of replicates
  2. Variance within treatments - natural variability
  3. Effect size - the magnitude of difference between means
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17
Q

What is index of dispersion?

A

A statistic used to quantify whether observed occurrences are clustered or dispersed compared to a standard statistical model, like a Poisson distribution.

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18
Q

What factors make a habitat suitable to sustain a population?

A
  1. Water availability
  2. Temperature range
  3. Food availability
  4. Terrain
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19
Q

What are some moisture related variables?

A

Precipitation, relative humidity, soil moisture

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20
Q

What are temperature related variables?

A

Mean annual temperature (MAT), summer maximum, winter soil temperatures, number of frost days, season of ice cover

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21
Q

What are the interactions that occur between moisture and temperature?

A

At higher temperatures more moisture is required by species within the environment; at high moistures, higher temperatures are tolerated.

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22
Q

What are the climatic limits to Argentine ant distribution?

A

Soil moisture limits the abundance of southern-californian ants. In a hot and dry environment soil moisture limits their distribution. They have lower heat tolerance than the native california ants.

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23
Q

What do mechanistic (physiological) models deduce?

A

Climate tolerances from eco-physiology.

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24
Q

How does temperature affect foraging behaviour according to mechanistic models?

A

There is a maximum soil surface temperature for foraging.

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25
What is the minimum temperature requirement according to mechanistic models?
Minimum temperature requirements for development of brood.
26
DEGREE-DAY MODEL
Mathematical models that predict an organism's developmental rate based on the temperature of its habitat.
27
What was the degree day model used for the Argentine ant?
From controlled lab rearings, it was deduced that development of Argentine ants from egg to adult required 445 degree-days above a threshold of 15.9 degrees
28
What were the results of the degree-day model for the argentine ant?
The ants required 445 days at 16.9 degrees, 222.5 days at 17.9 degrees or 44.5 days at 25.9 for the eggs to grow to adults.
29
scales of dispersal
1. spatial scale
30
intercontinental, regional and local
31
2. temporal scale
32
millions of years, multiple generations, 1-10 generations
33
Why is there a beech gap in new zealand?
glacial seperation of species, soil microbes and fungi no longer able to form mutualisms to build beech forest in the middle of the south island
34
diffusive spread
diffusion is a simple model of spread. this assumes complete random movmenet of individuals like molecules of gas
35
Random walks
fully random walks and autocorrelated random walks. these models are to predict dispersal. both of these behave like diffusion over time.
36
What does evolution of dispersal have to do with cane toads in australia?
There was a predicted distribution for invasive cane toads in australia. but this expanded more rapidly than expected. This is because the toads that are better dispersers breed on the edges of ranges and along coastlines and create babies that are better at dispersal.
37
Seed shadows
spatial distribution of dispersed seeds from a maternal plant
38
stochastic events
Random events that lead the the extinction of a population
39
Why do small populations have high rates of extinction?
Stochastic events
40
why are suitable habitats for small populations sometimes unoccupied by said population?
Because small populations have high rates of extinction due to stochastic events
41
true or false: empty isolated habitat patches have a high rate of colonisation
False empty isolated habitat patches have low rates of colonisation idiot
42
What do metapopulations require for their persistence?
for local colonisation rates to exceed local extinction rates.
43
source-sink dynamics
when unsuitable habitat is often occupied
44
matrix
interconnected habitats
45
what does the quality of the matrix do?
determines the rates of colonisation and the metapopulation persistence
46
what is a downside to fragmented habitats?
lots of edge habitat, increasingly less interior habitat
47
What is better, a large single habitat or many small fragmented ones?
A large single habitat
48
complementarity in species lists for reserves
Spreading reserves to encompass a range of different species, for example biota of floodplains but also mountain ranges
49
The world is green hypothesis
predators limit herbivores and allow plants to flourish. Biomass can only accumulate because of predators
50
Standing crop biomass
the amount of accumulated organic matter found in an area at a given time
51
Gross primary production
GPP - Energy (carbon) fixed via photosynthesis per unit time. Does not account losses from plant respiration
52
Net Primary productivity (NPP)
Gross primary productivity minus respiration losses (GPP - R)
53
What are some methods to measure Net PP (GPP - R)?
1. measure gas exchange around the leaves to get uptake of CO2 or release of O2
54
2. Harvest the plants (and measure the change in standing crop biomass + herbivory and death)
55
3. Satellite measure the plant biomass and all of the climatic and environmental conditions to estimate
56
What's an example of a machine used to measure gas exchanges of a plant?
Gas flux measurement devices they look like plastic cages
57
Of stems, leaves and roots, which have the highest rates of NPP on average?
Leaves and roots, stems in trees can just be dead tissue.
58
What biomes have the highest global GPP per year?
Tropical forests, tropical savannah and grasslands
59
What biomes have the highest ecosystem NPP per year?
Tropical forest by far has the highest.
60
What biomes have the lowest GPP per year?
Croplands and tundra.
61
what biomes have the lowest NPP per year?
Deserts and tundra
62
What are the major limitations on productivity for Terrestrial biomes?
Heat, water and light, disturbances in the successional stage of the ecosystem and soil nutrients particularly nitrogen.
63
What are the major limitations on productivity for Marine ecosystems
Surface waters are limited by nutrients like nitrogen and iron. Deep waters are limited by Light and warmth.
64
What are the major limitations of productivity for freshwater lakes and rivers?
Nutrients (Phosphorus and nitrogen)
65
Evapotranspiration
The combined amount of evaporation and transpiration
66
What is the correlation between different biomes that have high rates of evapotranspiration?
They often have high productivity.
67
What are tropical forests often limited by and why?
They are limited by light availability because of the high biomass and also due to clouds formed by high rates of evapotranspiration
68
Why does daily NPP change?
During the growing season NPP is affected by climate variables like UV, rain and humidity
69
When does NPP peak over a forests lifespan?
Midway and then declines. Mature forests are carbon neutral as trees start to die, gains are the same as the losses.
70
True or false: Mature forests are the most efficient type of carbon capture ecosystems
False. Mature forests are roughly carbon neutral as gains = losses
71
Negative Interactions
competition, predation, parasitism, herbivory, allelopathy.
72
What can negative interactions with other species do a species potential range?
It can restrict a species to a subset of its potential range especially at sub-optimal sites
73
positive interactions
those in which one or both species benefit and neither is harmed. these can extend a species range into "hostile" environments
74
What is facilitation in ecology?
An interaction in which one species has a positive effect on the survival and reproduction of another species.
75
Does facilitation involve a symbiotic relationship?
No, facilitation occurs without the intimate association of a symbiosis.
76
Describe the example of alpine cushion plants as facilitators
Azorella aretiodies facilitated 8 species relationships. R.Exima showed more species inside cushions than outside.
77
lichens as mutualists?
Lichens have a symbiosis with fungi and algae. The fungus receives sugars and algae receives water and physical protection. The range of habitats they can occupy as a lichen is enhanced than both the algae and fungi.
78
What is competition in ecology?
The struggle between organisms to survive in a habitat with limited resources.
79
At what spatial scales is competition more likely to be observable?
Fine spatial scales.
80
What can competition eventually change?
A species range boundary.
81
Whats an example of displacement by invasive species?
When maori introduced Kiore, pacific rat to new zealand, and then ship rats and norway rats were introduced later. Kiore were displaced from the mainland by ship rats and now Kiore only are in fiordland and offshore islands
82
What is predation?
The act of one organism consuming another for food.
83
How does predation affect the distribution of prey?
Predation has very strong and clear effects on both broad and fine scale distribution of the prey.
84
Can specialist predators exist beyond the range of their prey?
No, specialist predators cannot exist beyond the range of their prey.
85
Prey limited predators
Predators that can't exist beyond the range of their prey
86
Monophagus herbivores
herbivores that only eat one type of plant
87
What is the example of the specialist butterfly limited by host plant & climate?
boloria titania significantly limited by distribution of host plant not matching it's potential range
88
predator limited prey
When generalist and widespread predators restrict the distribution of their prey
89
What is thermal squeeze in New Zealand?
Endemic birds only persisting in the cooler, higher altitude forests.
90
Why are endemic birds in New Zealand at risk due to climate change?
Climate change allows rats to go to higher altitudes.
91
What is the thermal squeeze situation in Hawaii?
Endemic birds in hawaii are suffering thermal squeeze which is exacerbated by avian malaria mosquitoes that can only make it halfway up the mountain. The mosquitoes have a wider range of distribution after climate change
92
Ecosystem engineers
a keystone species that creates or maintains habitat for other species
93
What is an example of an ecosystem engineer?
Rabbits
94
What caused the decline of the Silver spotted skipper in the UK during 1960-70?
Loss of short-turf grassland
95
What happened to rabbit populations in the UK between 1980-2000s?
They recovered from disease and increased in numbers
96
How did rabbits contribute to the habitat of the Silver spotted skipper?
They created bare patches and increased microsite suitability
97
What contributes to density and distribution of seeds?
1. Density and distribution of parent trees
98
2. Seed prodcution
99
3. Dispersal of seed
100
What contributed to density and distribution of seedlings
Survival and germination of seed
101
Seed shadows
spatial distribution of dispersed seeds from a maternal plant
102
What is the difference in seed shadows between wind and animal dispersed trees?
Seed shadows are wider in wind dispersed trees and lower in animal dispersed trees.
103
What is low adult density/clumping of adults associated with?
Seed does not reach much of the ground surface
104
What is low seed production associated with?
Low seed dispersal across shorter distances
105
what is one of the strongest filters on future distribution of trees?
Establishment limitation. Environmental gradients are a big factor in this limitation.
106
Jump dispersal
A long-distance dispersal event by which a species colonizes a new geographic region.
107
Two-phase models
Two types of dispersal models, for example Local diffusion & Long-distance jump dispersal.
108
What is the example of "two-phase" dispersal models using argentine ants?
New colonies of this species are formed naturally by "budding' when a queen walks to a new nest site. This is local diffusion. But These ants have also spread really far distances or "jumped" and are found in smalll patches globally.
109
When were Argentine ants first discovered in New Zealand?
1990
110
In which city were Argentine ants first discovered in New Zealand?
Auckland
111
How many records of Argentine ants were there until 2000?
Few records
112
In what type of areas are Argentine ants distributed in New Zealand?
Areas where the mean July temperature is between 7-14 degrees Celsius.
113
In how many towns and cities are Argentine ants recorded in New Zealand now?
Many towns and cities
114
What is the highest rate of gene dispersal in plants? Is it pollen or seed dispersal?
Pollen dispersal.
115
Two types of migration
Learned and innate
116
benefits to migration
-Avoid harsh environmental conditions
117
-expand resource base by separating and breeding and overwintering grounds
118
What is a benefit of being the first seed to colonize an empty island?
You can colonize quickly.
119
What is a negative aspect of seed dispersal on an island?
Seeds can be blown off the island.
120
What may populations on islands experience selection for?
Reduced dispersal ability.
121
Extent of Occurance (EOO)
the area enclosed by the shortest continuous boundary that encompasses all known, inferred, and projected sites of a species' current occurrence. It's essentially a minimum convex polygon drawn around the species' distribution
122
Area of Occupancy (AOO)
the area within a species' range that is actually occupied by that species, excluding areas where it is only found occasionally.
123
AOO versus EOO
EOO - much broader, larger and includes the range of the species. AOO is the actual places that the species currently occupies. EOO includes a lot of unoccupied area. Both are range sizes.
124
Statistical distribution of range sizes
follows a log-normal distribution, on a logarithmic scale it appears normal. Most species have relatively small range sizes.
125
Rapoport's Rule
As latitude decreases, the geographic ranges of individual species shrink steadily. Larger at higher altitudes and smaller in the tropics.
126
what is one hypotheses to explain rapoports rule?
1. climatic variability is greater at higher latitudes. If this were true then in the ocean where variability is the highest at MID latitudes, we will see environmental tolerances at their highest at mid-latitudes. but range sizes of marine fish are greatest in the tropics.
127
what are some other explanations for Rapaports rule?
2. Dispersal ability after glaciation, better dispersing species have moved poleward.
128
3. less competition at high latitudes due to lower species richness, therefore less need to specialise.
129
All three explanations might be partially correct.
130
Something to remember about Rapoport's rule
It is not universal and is highly researched in mammals in north America and Eurasia. Glaciation also is not global.
131
What is abundance in ecological terms?
Abundance is a finer scale concept than distribution.
132
How is abundance measured?
Abundance is measured as the total number of individuals (n), density in a defined area where present, and occupancy of fine-scale subunits.
133
What is absolute abundance?
Absolute abundance is the number of individuals in an area or volume.
134
How can absolute abundance be expressed?
Absolute abundance can be expressed as a density.
135
What is relative abundance?
Relative abundance is usually based on numbers per unit effort of sampling.
136
How do you measure relative abundance?
index of abundance.
137
When would you use relative abundance as a unit of measurement?
Relative abundance can be useful for comparing the relative density of a species between sites or between times.
138
What are some examples of devices that measure relative abundance?
Pitfall traps and tracking tunnels
139
What is the standard method in new zealand to measure birds?
5-minute bird count
140
population size
Total number of individuals across all subpopulations
141
demographic stochasticity
variation in birth rates and death rates due to random differences among individuals
142
What types of population densities are most at risk for extinctions due to demographic stochasticity?
Species with low local population densities
143
What are species with restricted ranges at risk from?
Localised catastrophes, for example fire on Stephens Island tuatara population of 30,000+ individuals
144
What are the 4 different types of Point pattern processes ?
Scattered, common & widespread, Rare & local, localised

BIOL327 - Pop/Comm Ecology (1 decks)

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