Ecology Flashcards
(102 cards)
1
Q
What is organismal ecology?
A
concerned with behavioural, physiological and morphological traits that mediate interaction
- among individuals
- between species
- with environment
2
Q
What is a population?
A
group of individuals of the same species living and interacting in a particular geographic area
3
Q
What is population ecology?
A
Exams factors that limit and regulate population size and composition
4
Q
What is a community?
A
Consists of all individuals of all the species that inhabit a particular geographic area
5
Q
What is community ecology?
A
Examines the interactions among populations
(factors such as predation, competition and disease affect community structure)
6
Q
What are the 6 key processes that drive distribution and abundance?
A
Colonisation
Extinction
Birth
Death
Immigration
Emigration
7
Q
What is a limitation of the term communities?
A
Doesn’t show migration
8
Q
What happens to the population growth rate when births=deaths, immigration=emigration and colonisation=extinction?
A
0
9
Q
What are unitary organsims?
A
- easy to recognise genetically separate individuals
- form is programmed at birth
- local damage has serious consequence
9
Q
What are unitary organsims?
A
- easy to recognise genetically separate individuals
- form is programmed at birth
- local damage has serious consequence
10
Q
What are modular organsims?
A
- genetic individual, starts as zygote and docent follow set of development programmes
- growth occurs by repeated production of modules
- not predictable
- not dead until all modules are dead (local damage unimportant)
10
Q
What are modular organsims?
A
- genetic individual, starts as zygote and docent follow set of development programmes
- growth occurs by repeated production of modules
- not predictable
- not dead until all modules are dead (local damage unimportant)
11
Q
What is important when describing populations?
A
Composition is important:
- male vs female
- sizes
- juveniles vs adults
- age class
11
Q
What is important when describing populations?
A
Composition is important:
- male vs female
- sizes
- juveniles vs adults
- age class
12
Q
What 3 traits affect reproduction and mortality?
A
Rates - somatic growth
Timing - maturation and frequency of reproduction
Allocation - offspring size and number
13
Q
2 ways of describing life histories
A
- frequency of reproduction
- seasonal timing of reproduction
14
Q
What is semelparity?
A
- Big Bang reproduction
- Large number of offspring produced then dies
15
Q
What is iteroparity?
A
- reproduction is spread out
- repeated episodes
16
Q
2 types of reproduction
A
seasonal
continuous
17
Q
What are annuals?
A
- have one generation per year
- spent part of their life as seed (however can live as a seed for over a year)
17
Q
What are annuals?
A
- have one generation per year
- spent part of their life as seed (however can live as a seed for over a year)
18
Q
What is a Darwinian demons?
A
- organsims that lives for hundreds of years that reproduces frequently and large number of offspring
- cannot exist as life histories are contained by external factors and trade-offs
19
Q
What is principle of allocation?
A
each organism has a limited amount of energy it can allocate for maitenance, survival, growth and reproduction
20
Q
Give examples of trade-offs
A
Reproduction vs survival
Reproduction vs growth
Reproduction vs condition
Number of offspring vs size of offspring
Parental survival vs num
21
What is survivorship?
describes how many individuals in a population are expected to survive to any specific age (x)
22
What are life tables?
Summarise births and deaths for organisms at different ages of their life
23
What are the 2 types of life tables?
Cohort life table (age-specific rates over lifetime of a cohort of organisms)
Period life table (age specific rates during specific time period of certain population)
24
What are the 3 phases of reproduction?
Juvenile phase
Reproductive phase
Post reproductive phase
25
What is Net reproductive rate?
Average number of offspring produced by one individual female over her lifetime (how much a population grows per generation)
26
What is generation time?
Average time between successive generations (pace of life)
27
Why can infectious disease epidemics be useful/
- Measure of per-epidemic growth rate
- Measure of parasite fitness
28
What are the 2 parts of the life cycle diagram?
States - age group (newborn, adult)
Transactions - numbers that describe rates (survival, reproduction)
29
What is the Matrix projection models (MPMs) USEFUL?
- calculates the population will persist or go extinct
- looks at short-term behaviour (predict impact of reintroduction
strategies)
- extract population growth rate from model
30
What is exponential population growth?
- population with few individuals
- environment with no limiting factor (resources are limited)
- no limitation on available energy
- no restriction on growth or reproduction
31
What is K?
the carrying capacity (itra specific competition)
- crowding
- resource limitation
32
Why is predation important?
Ecology - structure and dynamics of communities
Evolution - selects for morphology, behaviour
Agriculture - pesticides
Conservation - predator control, reintroduction
Biodiversity - richness
33
4 types of interaction
Competition -/-
Predation +/-
Mutualism +/+
Commensalism +/=
34
What are predator strategies?
Traits - camo, trickery, mobility, morphology
Behaviour - sit and wait, purse, stalk
Domain - timing, spatial location
Mode - individual, group
35
What are prey strategies?
Traits - mobility, camo, mimicry, chemical defence
Behaviour - warning signals, play dead
Domain shifts - time, space
Safety in numbers - predator confusion, vigilance
36
What are inducible defences?
Defences not there all the time
37
What is a keystone species?
Regulates species in environment, reduces a dominant species
38
What is a trophic cascade?
- The indirect interactions between non-adjacent trophic levels
- Predator > prey > resource
- predator-prey, prey-resource, Direct effect
- predator-resource, Indirect effect
39
What are impacts of loss of predators?
- loss of plant diversity and biomass
- loss of herbivore density
- effects on water quality, PH, Co2 flux
40
What is the inflection point?
Point at fastest growth rate
41
What is trophic downgrading?
refers to the negative effects of predator loss on lower trophic levels
42
What growth and functional response are density dependent?
Exponential growth, type 1 - density independent
Logistic growth, type 3 - density dependent
type 2 - inverse density dependent
43
What is the optimal foraging theory?
Are organisms choosy or eat at random
44
What decides diet choice?
Currency - energy, time
Objective - maximise energy intake and time spent foraging
Constraints - time available for feeding, space, nutrients /toxins
45
What is the contingency model of foraging?
Profit = E/h
E=energy (calories)
h=handling time
46
Examples of resources
food, shelter, mates, nutrients, territory, climate
47
2 ways individuals compete
Indirect (cost is loss of resource)
- exploitation
- pre emptive (using space)
Interference (cost is loss of resource/fighting)
- overgrowth
- chemical
- territorial
48
What did George Gause do?
Paramecium experiment for competition (inter/intraspecific competition)
3 jars, Species A, Species B, Species A/B
Not large impact of growth rate, large impact on K
Competitive exclusion principle
49
What is competitive exclusion principle (George Gause)?
- no 2 species can share same resources
- no 2 species can occupy same niche
- 2 species can't coexist when have identical needs of limited resource
50
What is the niche?
Fundamental - intrinsic requirements of a species on its own (physiological and ecological limits)
51
Lotka and Volterra
Shows 2 species competing leading to either coexistence of exclusion
52
When do competitors coexist?
Intraspecific Competition >> Interspecific Competition
Intraspecific Density Dependence >> Interspecific Interactions
Coexistence occurs when each species consumes the resource most limiting to it faster than other resources, and that limiting resource is not the same for both species
53
What is R* theory?
Compares resources and species coexistence
Lines cross - coexistence
Lines don't cross - exclusion
R* theory predicts preference is essential for coexistence in a multidimensional resource environment
54
What contributes to evolution?
Favours separating niches, minimising interspecific competition (promoting coexistence)
55
Theories on biodiversity - function
Species may add function due to complementarity
Species are primarily redundant, most function achieved with small number of species (redundancy hypothosis)
56
Biodiversity - function evidence
Hump back curve (intermediate biomass has greatest biodiversity)
Global analysis, 48 global sites, 1 negative concave site (hump back curve no applicable)
Global update, analysis of all sites finds concave fit (hump back may be applicable)
Pan et al - biomass increases with species richness (linear)
Naeem et al - growth chambers with different diversity (increase in biomass with increase species)
Hector et al - European synthesised grasslands (species loss reduced biomass production), functional groups in study: grasses, legume, non-legume forms
Thompson et al - immature vs mature communties (negative relationship for biodiversity-function)
57
What is bio-depth?
As biodiveristy decreases biomass decreases
58
What is wrong with term species richness?
no identity of species (no composition)
ecosystem function is driven by characteristics of species
59
Why does species identity matter?
traits drive ecosystem function
plant traits: real characteristics of plant (growth rate, leaf thickness, leaf N)
60
What is Grimes mass ratio hypothesis?
controls are ecosystem are in proportion to biomass or productivity (richness of subordinate species has little influence)
61
What is Grimes mass ratio hypothesis?
controls are ecosystem are in proportion to biomass or productivity (richness of subordinate species has little influence)
62
What are legumes, herbs and grasses?
Legumes - fruit of seed of plant
63
How do grasses impact nitrate leaching?
reduce nitrate leaching
64
What is the mass ratio hypothesis?
plants with greater biomass probably influence ecosystem properties more
65
What is macro ecology?
Uses compilations go data to study large scale ecology patterns in space/time
66
3 key aspects of macro ecology
- large scales
- strongly empirical observational approach
- emergent non-reductionist approach
67
What does range size refer to?
the geographical distribution - distributions are patchy and scale dependent
67
What does range size refer to?
the geographical distribution - distributions are patchy and scale dependent
68
How do you measure ranges?
Extent of occurrence - includes gaps
Area of occupancy - excludes gaps
69
What species are at biggest risk?
those with small range size (increase extinction risk)
70
What species are at biggest risk?
those with small range size (increase extinction risk)
71
What was Rapoports rule?
Species have smaller latitudinal ranges at low latitudes (however pattern is a local phenomenon)
72
What is climatic tolerance?
-Seasonal variation greatest at high latitudes
- Species at high latitudes cope with range of temperatures (more physically capable)
- Small range species at more risk at high latitude
73
What are taxon cycles?
Speciation - expansion - contraction - extinction
73
What are taxon cycles?
Speciation - expansion - contraction - extinction
74
What is the climatic variability hypothesis?
taxa from variable habitats evolve wider environmental tolerances - establish wider distributions along climate gradients
75
What is the climatic variability hypothesis?
taxa from variable habitats evolve wider environmental tolerances - establish wider distributions along climate gradients
(latitudes and altitudes)
76
Where is probability of speciation highest?
At a medium range size
- to large can go round barrier seperating
- to small at risk of extinction
77
Why is there more species in a larger area?
more area = more habitat diversity = more niches = more species
more area = larger population = reduced extinction risk = more species
77
Why is there more species in a larger area?
more area = more habitat diversity = more niches = more species
more area = larger population = reduced extinction risk = more species
78
What is saturation by isolation?
saturation measures number of species on an island relative to possible species that could occur given pool of species on mainland
(distant islands less saturated)
79
What is the island biogeography theory?
Balance between immigration and extinction = species richness
80
How are immigration and extinction rates affected by area and isolation?
- immigration increase with area
- extinction rates decrease with area
- immigration rates decline with isolation
- extinction rates increase with isolation
81
What is the latitudinal diversity gradient (LDG)?
change in species over latitude, more richness to equator
82
What causes latitudinal gradient?
net diversification = speciation - extinction
net migration = immigration - emigration
(chance events, ecological factors, evolutionary factors)
83
What is the mid domaine model?
Species move to centre of domaine of land
84
Why get more species when productivity is higher?
- chance (more energy = more individuals, increase species diversity by chance)
- more individuals hypothesis, larger populations reduce risk of extinction
- more trophic lvls (more energy at base and support higher lvls)
- dynamic equilibrium, more energy allows faster recovery, reducing excitation risk
- niche, species can co-exist
85
How does evolutionary factors affect LDG?
tropics are diverse: (also richness of first occurrence)
high speciation, cradles
low rates of extinction (have older species), museums
high immigration / low immigration, engines
85
How does evolutionary factors affect LDG?
tropics are diverse: (also richness of first occurrence)
high speciation, cradles
low rates of extinction (have older species), museums
high immigration / low immigration, engines
86
Why do tropics have higher diversification rates?
- mutation rates - higher temps, higher UV
- more niches
87
What are windward and leeward slopes?
Windward - faces wind
Leeward - sheltered from prevailing winds
88
What is the ecology of fear?
Psychological impact that predators induce on prey (impacting behaviour)
89
What is fixed quota harvesting?
Fixed quota harvesting = constant harvest rate
Generate 1 stable equilibrium and vulnerable to population fluctuations (may place harvest rate above recruitment rate)
89
What is fixed quota harvesting?
Fixed quota harvesting = constant harvest rate
90
What is fixed effort harvesting?
Fixed effort harvesting = constant efficiency rate
Harvest that increases linearly with population size as a function of a fixed effort (less vulnerable to population fluctuations)
91
What is maximum sustainable yield?
Theoretically largest yield possible where the population won't be depleted
harvest rate = recruitment rate
92
How does mortality rate change with the 3 response types?
1 - constant mortality rate
2 - mortality rate decreases with density (most common)
3 - mortality rate increases then decreases with density
93
What does coexistence require?
Density dependence
(predation, competition, disease)
