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Flashcards in Community Ecology (PP23) Deck (98)
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1
Q

define metacommunities

A

group of communities between which movement & interactions may take place

2
Q

what does community ecology consider

A

Considers the interactions between all species in a defined geography

Species inhabit specific niches within their environment, which affects how they interact with the larger community

3
Q

what is phenolgy and If a certain prey / predator changes its behaviour due to seasonal changes, will it have consequences on the dynamic of the community?

A

Study of plant & animal life cycles & how these are influenced by seasonal changes in climate

yes it will have significant consequences

4
Q

explain niche

A

specific ecological role a particular species plays, as well as the biotic & abiotic influences the environment has on that organism

5
Q

what is a fundemental niche?

A

full range of resources or habitat a species could exploit if there was no competition with other species (i.e. theoretical niche)

6
Q

what is a realized niche

A

resources or habitat a species actually uses (i.e. actual niche)

7
Q

what are the two ecological niches and explain them.

give an example of a species that is each of them

A

Generalist: very broad niche (consumes many types of resources) (ie. Racoon/ seagull)

Specialist: very narrow niche (consumes only a small range of resources) (ie. Koala, panda)

8
Q

define range

A

geographical area over which an organism lives

9
Q

What is a species range determined by?

A

Each species has its own range determined by physiological & resource constraints

10
Q

When is considering range important?

A

Important when considering the specific habitat of an organism & what this means for the population and community ecology

11
Q

What are populations linked by and what do they affect

A

Populations are linked by interspecific interactions that affect the survival & reproduction of the species engaged in the interaction

12
Q

what are the community interactions`

A
Competition 
Predation 
Herbivory
Parasitism (e.g. disease)
Symbiosis (mutualism / commensalism)
13
Q

What does intraspecific mean?

A

competition among members of the same species

Often intense due to same space and nutritional requirements

14
Q

what does interspecific mean?

A

competition between members of different species

15
Q

define terrioriality

A

organisms defend specific areas
Primarily against members of own species.
Resource allocation & spacing

16
Q

what is the Principle of Competitive Exclusion

A

2 species cannot occupy the exact same niche for a prolonged period:
One will eventually out-compete the other & claim that resource

17
Q

what will happen to the losing species according to the principle of competitive exclusion

A

Losing species will either migrate, become extinct, or partition the resource (utilize a sub-set of the same resource)

18
Q

give an example of the principle of competitive exclusion

A

you will generally not find foxes & coyotes living in the same area due to competitive exclusion

19
Q

what are predator adaptations

A

Claws, teeth, fangs, stingers, venom

20
Q

what are prey adaptations?

A

Colouration, mimicry, detachment / vomiting, spines, bioluminescence, toxins

21
Q

exaplain cryptic coloration give an example

A

Cryptic colouring: colouration blends in with its environment, so not be easily detected by predators (camouflage)
lizard camouflaging on brach

22
Q

explain disruptive colouring and give an example

A

Disruptive colouring: colouration hides the physical “edges” (ends) - strong contrasts in light & dark across the patterns of the animal
(ex. zebra)

23
Q

explain counter shading and give an example

A

Counter shading: helps cancel the effects of shading / shadows, of an animal - have a lighter underside & darker upper part cancel out natural shadow
(deer)

24
Q

explain aposematic colouring

A

Aposematic colouring: poisonous organisms tend to be brightly coloured to warn predators that they are, in fact, poisonous

25
Q

are all animals that display aposematic colouration actually poisonous?

A

Not all animals that display aposematic colouration are actually poisonous – some only mimic animals that are poisonous.

26
Q

True or false? Predators never learn to avoid types of animals with bright colouration>

A

false, the bright colouration serves as a warning in the future

27
Q

explain batesian mimicry

A

Batesian mimicry: animal that lacks poison / venom appears similar to another animal that is

28
Q

explain mullerian mimicry

A

Müllerian mimicry: animal that mimics a poisonous / venomous one still has some poison, though not necessarily to the same degree

29
Q

explain aggressive mimicry

A

Aggressive mimicry: predator attracts its prey towards itself with a lure or mimicked cry

30
Q

what is symbiosis

A

Relationship in which 2 or more organisms are closely associated in a way that benefits at least 1 of the participants

31
Q

explain mutualism and give an explanation

A

Both organisms in an interaction benefit from one another: Win / Win (+/+)

e.g. Humans & intestinal flora: while there may be a slight disadvantage in this relationship (have to carry the bacteria around), this disadvantage is outweighed by the benefit (help digest our food)

32
Q

explain facultative mutualism and give an example

A

Facultative: organisms are able to live without each-other

e.g. Clownfish & sea anemones

33
Q

explain obligate mutualism and give an example

A

Obligate: one organism cannot survive without the other

e.g. Yucca & yucca moth

34
Q

explain commensalism and give an example

A

One organism in an interaction benefits & one is unaffected: Win / Meh (+/0)

Remora fish (suckerfish) & sharks/whales: remora gets a snack while it hitches a ride on the fish/whale, while the latter isn’t much bothered but doesn’t gain anything

Cattle egret & buffalo: egret benefits from all the insects kicked up by the buffalo, which gets nothing in return

35
Q

explain parasitism and give an example

A

One organism in an interaction benefits at the expense of the other: Win / Lose (+/-)

Tapeworms & host: tapeworm enters intestinal tract, grows, & reproduces, causing the host abdominal pain, diarrhoea, weight loss

Disease & host: disease completes its life cycle at the expense of the host, causing physical symptoms & possibly death

36
Q

what are the two ways to measure species diversity and explain them

A

Species richness: total number of different species in the community
Does not take into account concentrations of different organisms

Relative abundance: compares the relative quantities (proportions) of different species in the same community & looks at density

37
Q

true or false: there is a latitudinal gradient of species diversity for most taxa

true or false: Species diversity increases as latitude increases?

PIC IN SLIDES

A

true

FALSE Species diversity declines as latitude increases

38
Q

increase in biodiversity is associated with what

A

increase in community productive
increase in community stability and
increase in ecosystem services

39
Q

explain increase of community productivity

A

↑ Community productivity:

  • Production of biomass (biological organisms) / reproduction
  • More diverse community has greater quantities of life forms
  • Enables different species to rely on those species from which they best obtain nutrients (greater selection)
40
Q

explain increase in community stability

A

↑ Community stability:
Resilience of community against extinction of 1 or more species
At low diversity, loss of 1 species triggers a domino effect leading to more extinctions

41
Q

explain increase in ecosystem services

A

↑ Ecosystem services:
Benefits to humans from an ecosystem (e.g. clean water)
Greater diversity means a broader range of organisms that can offer benefits

42
Q

define stability

A

Stability: constant composition or abundance

Consistent pattern in fluctuations

43
Q

what are the elements of stability

A

Resistance:
Resilience:
(Elasticity):
(Amplitude):

44
Q

what is elasticity

A

how quickly the system returns to its previous state

45
Q

what is amplitude

A

to what degree the system can be moved but still return to its previous state

46
Q

what is resilience

A

how much of the system’s function & structure is retained, & how easily/quickly can it recover

47
Q

what is resistance

A

how little / how much the system changes

48
Q

what is a climax/mature community

A

Climax / mature community: when a community reaches a relatively unchanging state
Will still cycle through small population changes, but will not undergo large changes (succession) until it faces a disturbance

49
Q

what is a disturbance

A

Any major event that has an impact on the community: can be abiotic or biotic

50
Q

what can a disturbance result in

SEE DIAGRAM IN SLIDES

A

Results in succession
Process whereby the community in a given habitat changes
(primary and secondary)

51
Q

explain primary succession

A

Primary succession: when community forms for very first time & new species arrive in a geographic region
only ever happens once

52
Q

explain secondary succession

A

Secondary succession: when growth and changes take place in the environment in response to the disturbance

53
Q

what are the 3 basic categories of organisms

A

producers (autotrophs)
consumers (heterotrophs)
decomposers

54
Q

explain decomposers

A

Decomposers
Break down / regenerate remains & waste products of plants & animals into simple inorganic nutrients
Major role in biogeochemical cycle

55
Q

explain producers

A

Producers (Autotrophs)
Produce own food through photosynthesis. Only way carbon & energy get into the system.
Autotrophic algae, bacteria, plants

56
Q

explain consumers

A
Consumers (Heterotrophs)
Depend on autotrophs or the organic compounds they produce for their food supply
Herbivores: eat plants or algae
Carnivores: eat other animals
Omnivores: eat both plants and animals
Bacteriovores: eat bacteria
57
Q

define herbivores

A

Herbivores: eat plants or algae

58
Q

define carnivores

A

Carnivores: eat other animals

59
Q

define omnivores

A

Omnivores: eat both plants and animals

60
Q

define bacteriovores

A

Bacteriovores: eat bacteria

61
Q

define trophic level

A

each of the different feeding levels of organisms

62
Q

what are the 3 basic trophic levels

A

1st: primary producers (autotrophic phytoplankton & plants)
2nd: herbivores (zooplankton & animals feeding on plants)
3rd: carnivores (animals feeding on other animals)

63
Q

True of false: Total biomass decreases with increasing trophic level

A

true

64
Q

what is the 10% law of ecological efficiency

A

: only about 10% of the resources from one trophic level are passed on to the next level

65
Q

define transfer efficiency

A

energy provided to the next higher trophic level divided by the energy received from the next lower trophic level

66
Q

What are losses of mass and energy due to ?

A

Losses of mass & energy within each trophic level due to respiration, feces, etc.

67
Q

who invented the 10% rule

A

lindemen

68
Q

what do food webs do?

A

Food webs link the trophic levels from producers to top carnivores

69
Q

who is the primary consumer

A

Primary consumer: herbivore (plant eater)

70
Q

who is the secondary consumer

A

Secondary consumer: carnivore (meat eater): tertiary consumer

71
Q

what does an omnivore do?

A

Omnivore: eats both plants & animals

72
Q

what does the top carnivore do?

A

Top Carnivore: eats other carnivores

73
Q

who are the decomposers

A

Decomposers: detritivores (detritus eater): bacteria

74
Q

who are the phototrophs

A

Phototrophs: plants, algae (phytoplankton), bacteria

75
Q

who are the primary producers

A

autotrophs

76
Q

FOOD WEB DIAGRAM

A

LOOK IN SLIDES

77
Q

what is a food chain

A

simple, linear sequence of organisms through which energy is transferred

78
Q

true or false Usually only 1 species at the consumer levels

A

TRUE

79
Q

food chain show…

A

Highest transfer efficiency and maximum harvest

80
Q

what is a food web?

A

complex food chain with many links between producers and consumers

81
Q

what is the problem but also upside of a food web?

A

Less efficient but more resilient

82
Q

what is a keystone species

A

: particularly important part in a trophic web

83
Q

what will the disruption of a keystone species cause?

A

Its disruption will cause a major trophic cascade

84
Q

what is the argument of keystone species

A

Argument that, in one way or another, all animals are keystone species, since it is impossible to remove one species entirely without having major impacts on a trophic web

85
Q

KEYSTONE OTTER SLIDE

A

NOTE SLIDE

86
Q

what is a Bottom-up trophic cascade

A

Bottom-up trophic cascade: If an animal that is lower on a trophic pyramid is removed

87
Q

what is the consequence of bottom up trophic cascade and give an example

A

Subsequent layers of the pyramid will be impacted & will diminish
e.g. if a primary producer is reduced, this will decrease the presence of primary consumers, which will decrease the presence of secondary consumers, etc.

88
Q

what is the consequence of top-down trophic cascade

A

Population of the next highest trophic level will increase → this increase will result in a decrease in the next trophic level, which causes an increase in the level below it, etc.

89
Q

What is a Top-down trophic cascade

A

: elimination of a higher predator

90
Q

what will trophic cascade shifts cause?

A

These shifts emphasize the important interspecific interactions within an ecosystem

91
Q

what is bioaccumulation

A

organism cannot eliminate the toxin → toxin accumulates over its lifetime

92
Q

what is the result of bioaccumulation?

A

Results in increased concentration of toxin in the organism’s body

93
Q

true or false: When an organism affected by bioaccumulation is eaten by a higher trophic level-animal, the toxins pass to this animal

A

true

94
Q

give examples of toxins

A

DDT, PCBs, Mg

95
Q

what is bio-magnification

A

Bio-magnification: toxins become more concentrated with each successive trophic level

96
Q

what does bio-magnification result from>

A

Results from biomass at each trophic level being produced from a much larger biomass ingested from level below

97
Q

biomagnification occurs under what conditions

A
  • Pollutant/toxin must be long-lived.
  • Pollutant/toxin must be concentrated by producers
  • Pollutant/toxin must be fat-soluble & transferred to higher trophic levels
98
Q

what is the schema of the concentration of toxin

A

Concentration of toxin:

3rd trophic > 2nd trophic > 1st trophic