living together Flashcards
(91 cards)
1
Q
what is community structure?
A
how rich a community is
- genetically
- morphologically and behaviourally
- taxnomically
- functionally
how evenly represented the species / functional groups are within the community
2
Q
what is a community?
A
an interacting group of various species in the same location
3
Q
what makes up a phenotype?
A
- morphological characteristics
- biochemical or physiological properties
- phenology
- behaviour
the organisms genes, environmental factors or both
4
Q
what is a functional group?
A
a set of species that each have:
- similar effects on ecosystem processes
- similar responses to environmental conditions
5
Q
what does the presence of similar function traits among species indicate?
A
that it is an ecosytsem high in functional redundancy
6
Q
what does functional redundancy mean?
A
- species feed similarly
- reproduce the same
- live in same habitat
- carry out same processes
7
Q
fundamental niche
A
set of biotic and abiotic resources an organism can potentially utilize
8
Q
realized niche
A
set of biotic and abiotic resources that an organism can actually use after interacting/competing with other species
subsample of the fundamental niche
9
Q
evenness
A
a description of the distribution of abundance across the species in a communit
10
Q
what is community composition?
A
- actual identitiy of species & functional groups that form a community
11
Q
what is community structure?
A
reflects the richness and evenness of the community
12
Q
what is ecosystem function?
A
refers to the capacity of ecosystems to carry out primary ecosystem processes
13
Q
what are the main ecosystem functions?
A
- capturing
- storing & transferring energy
- CO2
- nutrients
- waste
14
Q
keystone species and ecosystem functioning
A
- they affect organisms higher up or lower down the food chain
- larger effect on ecosystems relative to their abundance
- often a predator
- affects richness & evenness of communities
15
Q
autecology
A
interactions with the living and non-living factors of its environment
16
Q
what are life history traits?
A
traits that affect an organism´s schedule of birth and death
17
Q
examples of life history traits
A
- life stages
- mating system
- number of offspring
- parental care
- distribution of breeding events through life
- mortality
18
Q
semelparous
A
only breed once
19
Q
iteroparous
A
breed repeatedly
20
Q
reproductive value
A
- their expected contribution to future population growth
- determined by the age-specific vital rates
- present + expected future contribution to the population
21
Q
most successful life history strategy?
A
- high survival
- reproduction early
- many offspring
- highly invest in offspring
22
Q
life hustory trade-offs
A
- limited resources of time and energy
- different activities compete for same resources
- expenditure in one activity only possible at expense of other activities
-> giives rise to trade-offs
23
Q
r-selected species
A
- small
- short-lived
- mature early
- many small offspring
24
Q
k-selected species
A
- large
- long lived
- mature late
- few large offspring
25
what is a population?
group of individuals of same species that occur at a particular place at a particular time and interact with each other
26
how to count a population?
- total count
- sampling methods
- abundance indices
- genotyping
27
horizontal life tables
follow known individuals through time and record their birth rates and death
28
vertical life tables
identify age of indviduals and retrace when they were born
29
lotka´s theorem
when birth and mortality rates remian constant over time and reach a stable age distribution
30
r value
birth - death = r
- if slightly positive -> pop grows exponentially
31
what favours a positive r value?
- favourable environment
- low mortality
- high fecunidty
- early onset of reproduction
32
what regulates population growth?
- the climate school (pop limited by environmental factors - density independent)
- the biological school (limited resources that need to be shared between all individuals - density dependent)
33
dispersal
- movement of organisms from one location to another
- can be intentional: migration
- or passive: due to wind, water, species..
34
what can affect dispersal?
- local population dynamics
35
neutral theory
all species in a population are equal in their competitive abilities
a baseline scenario
36
fragmentation
- natural or anthropogenic
- affects dispersal
37
2 types of large scale movements
- migration
- dispersal
38
migration
- directional movement of large numbers of one species from one location to another in a predictable way
- predictable in time and space
39
migration strategies
- minimise cost of transport
- minimise duration
- minimise risk of predation
40
metapopulation
- has spatially discrete local populations
- migration between populations limited
41
connectivity
- predicted rate of immigration into a patch or predicted success of migrants leaving a patch
- without connectivity local patches may go extinct
- with connectivity excess productivity can be distributed over the region
- local recolonisation
42
what can affect population abundance?
- density of own population
- food thy eat
- being eaten
- competition with other species
43
types of interactions between species
- competition
- predation / parasitism / herbivory
- commensalism
- mutualism
44
competition
- each species suffers from the presence of the other
- direct aggression
- using up resources (inference competition)
- presence of a competing species can lower the carrying capacity of other species
45
graphs showing species competition
- left of line = space to grow
- right of line = above the carrying capacity
46
competitive exclusion principle
- two species with the same needs to not co-exist indefinitely
47
result of competition
- species occupy different niches
- morphological changes (e.g. darwin finches)
- affects distribution and abundance
48
predation
- positive to one population, detrimental to the other
- predators, parasites, plants can regulate their prey, host or herbivore population
49
lotka-volterra equation
frequently used to describe the dynamics of ecological systems in which two species interact, one a predator and one its prey.
50
commensalism
- one species benefits but not the other
- one more advantaged, other not negatively affected
51
mutualism
- positive reciprocal relationship between two species
- stable equilibirum (lotka-volt)
- 2 mutualistic species can regulate each others populations
52
communities
- assemblages of many populations that live in the same place at the same time
- shaped by fators acting between diff species (e.g. competition, preadtion...)
53
how are communities classified
most commonly based on climate and vegitation
54
diveristy of communities
communities can differ depending on
- species richness (number of species)
- evenness (distribution/number of individuals within each species)
55
food webs as trophic structures
producers = first trophic level
herbivores / primary consumer = second trophic level
carnivores / second. consumer = third trophic level
carnivores / tertiary consumer = fourth trophic level
56
how are trophic levels distributed?
- more prey than predators
- higher trophic levels cannot be higher because of the conversion of energy between levels -> energy lost
57
how can communities be characterised?
- species lists
- diversity indices
- food webs
58
spatial patterns in diversity
- latitude -> decreases with elevation, aridity, water depth
- temporal / sucession -> volcanic eruptions, atlantification of the arctic (changed communities)
59
what factors can affect diversity?
- species-area relationship
- size -> large areas more diverse bc more resources
- isolation -> closer to islands have higher colonisation rate bc easier to reach
- species interactions
- keystone species
- habitat complexity -> more complex = richer diveristy
- disturbance -> intermediate disturbanvce = diversity
60
keystone species
have a disproportionally large effect on natural environment due to its abundance
61
competition exclusion principle
- Competitive interactions among the populations of two species will lead to the exclusion of one of the species when the realized niche of the superior competitor encompasses the fundamental niche of the inferior competitor
- surviving species is better at using the limited resources
62
species-rich assemblages
- fine partitioning of feeding niches can support the diveristy of organisms at equilibrium
- use resources in diff parts of environment in complementary ways due to the development of different traits
63
changes in environmental conditions and competitive exclusion of species
- continually changing environmental conditions to not allow competitive exclusion of species
- conditions / resources in nature change all the time
- this helps species take advantage of different conditions -> each have a favourable one
64
intermediate disturbance hypothesis
- redicts that the highest diversity will occur at levels of moderate disturbance
- important for biodiversity
65
disturbances in rainforests
- windstorms
- landslips
- lightning
- insect plagues
- plant parasites
66
disturbances in corals
- storm waves
- freshwater floods
- sediments
- herds of predators
67
result of low disturbance
- low species diversity
- due to competitive exclusion
- k selected species
68
result of high disturbance
- low species diversity due to difficulty to regenerate and regian that diversity
- same for a large disturbing event
- only good colonizers or highly tolerant species can persist
- r selected species
69
when do you get maximum diversity?
- at intermediate disturbance frequencies
- species that thrive at both early and late successional stages can coexist
- mix of good colonisers and competitor species
70
r-strategist
- high / fast growth rate
- can grow fast at each resource pulse
71
k-strategist
- can survive when resources are low
- more likely to survive in the long term
- more competitive when resources are low
72
animal cooperation at a macro level
cooperation builds landscapes
e.g. corals and their algae symbionts
73
animal cooperation at a micro level
allows for digestion
e.g. gut commensals of ruminant mammals or termites
74
slavery / dulosis
- one species is being captured by another species and work for them
- e.g. social parsitism
- no physical dependence
- a one way advantage
75
brood parasitism
- the placing of eggs into the nest of another member of the same or a different species
- the different species rears the young of the brood parasite
76
brood parasitism - insects
- large blue butterfly and myrmica ants
- worker ants pick up catapillars
- catapillars grow and develop and exploit resources within ant nest
- pheromone mimicry -> catapillar smells like ant larvae
- can mimic noises of queen ant to make ants do what catapillar wants
77
brood parasitism - birds
- birds lay nest in other birds nest
- intra or interspecific
- bird then does not need to rear the young
- co-evolutionary arms race
- e.g. cuckoo -> lays eggs in nests of birds whos eggs it can mimic easily
78
counter defenses by brood parasites - evolutionary arms race
- if birds being "exploited" learn to be able to discriminate
- pass on info to others of same species
- giving them an advantage
- can work both ways
79
benefits of brood parasitism
- allows bird to have an increased fecundity -> able to reproduce a lot without needing to invest lots of energy
- greater allocation of resources to mating and producing more eggs
- dont need to defend nests, incubate eggs or feed the young
80
predator
organism that catches and kills other organisms for food
81
parasite
- organism that for all / some of its life derives its food from a living organism from another species (the host)
- lives at the expense of others
- lives in or on body of host (host often harmed)
82
parsitoid
- organism alternately parasitic and free living
- the parasitism ultimately kills the host
83
hyperparasitoid
secondary parasitoid on another parasite or parasitoid
84
entomopathogens
- pathogens that kill or seriously disable insects
- parasites acting as plant bodyguards
- (host can also act as a bodyguard for the parasitoid)
85
ectoparasites
live on skin of the host
derive their sustenance from skin
86
endoparasites
lives inside host
can have direct / indirect life cycles
87
hemimetabolous
- life cycle consists of egg, nymph, and adults
- having no pupal stage in the transition from larva to adult
88
holometabolous
- metamorphosis is characteristic of beetles, butterflies and moths, flies, and wasps
- their life cycle includes four stages: egg, larva (q.v.), pupa (q.v.), and adult.
89
advantages of parasitism
- secure physical and chemical environment
- homeostasis maintained by the host
- secure & abundant resources
- opportunity to reduce endogenous metabolic pathways
- resource availability for huge reproductive potential
- transmission routes available - faeces, urine...
- indirect / multiple host life cycles -> larva and adults can exploit different resources
90
disadvantages of parasitism - endoparasites
- finding a host
- navigating within host
- finding mates
- defensive reactions of the host -> parasite must evolve to counteract anitbodies etc...
91
disadvantages of parasitism - ectoparasites.
- host finding
- danger from blood-borne parasites for which they are vectors
- specialised feeding -> parasites need special mouthparts, blood supply enhancers...
