Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Ecology > ch. 18: community structure > Flashcards

ch. 18: community structure Flashcards

1
Q

ecotone

A
  • boundary b/w adjacent communities
  • transitional zone b/w ecosystems where there is a mix of species in both adjacent ecosystems
  • boundary created by sharp changes in environmental conditions over a relatively short distance, accompanied by a major change in the composition of species
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

interdependent communities

A

communities in which species depend on each other to exist

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

independent communities

A

communities in which species DO NOT depend on each other to exist

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

species richness

A

the number of species in community

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

relative abundance

A

proportion of individuals in a community represented by each species
- n/N
- n = number of individuals of 1 species
- N - total number of individuals of all species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

log-normal distribution

A

normal (bell-shaped curve) distribution that uses log-scale
- on x-axis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

rank-abundance curve

A

curve plot of relative abundance of each species in a community in rank order form most abundant species–>least abundant species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

species evenness

A

comparison of relative abundance of each species in community

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Simpson’s index

A

measurement of species diversity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

key-stone species

A

species that substantially affects the structure of communities despite the fact that individuals of species might not be particularly numerous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

intermediate disturbances hypothesis

A

hypothesis that more species are present in community that occasionally experiences disturbances than in community that experience frequent of rare disturbances

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

food chain

A

linear representation of how diff species in a community feed on each other

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

food web

A

complex and realistic representation of how species feed on each other in a community

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

trophic levels

A

level in a food chain or food web

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

primary consumer

A

species that eats producers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

secondary consumer

A

species that eats primary consumer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

tertiary consumer

A

species that eats secondary consumer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

omnivore

A

species that feeds at several trophic levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

guild

A

w/in trophic level; group of species that feeds on similar items

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

direct effect

A

interaction b/w 2 species that does involve other species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

indirect effect

A

interaction b/w 2 species that involves 1+ intermediate species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

density-mediated indirect effects

A

indirect effect caused by changes in density of intermediate species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

trait-mediated indirect effects

A

indirect effect caused by changes in traits of intermediate species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

trophic cascade

A

indirect effects in a community initiated by predator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

bottom-up control

A

when abundance of trophic groups in nature are determined by amnt of energy available from the producers in a community

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

top-down control

A

when abundance of trophic groups is determined by existence of predators at top of food web

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

community stability

A

ability of community to maintain particular structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

community resistance

A

amnt that a community changes when acted upon by some disturbances, such as addition and removal of species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

alternative stable states

A

when community is disturbed so much that species composition and relative abundance of populations in community change, and new community structures is resistant to further change

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

native

A

organisms naturally found in an ecosystem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

nonnative (Exotic, alien, invasive)

A

any organism not found naturally in ecosystem
- usually transported by humans

32
Q

indicator

A

organisms that serve as early warnings of damage to a community

33
Q

keystone species

A

organism has a disproportionate effect on the rest of the ecosystem
- strong interactions w/ other species affect life of others
- not necessarily numerous
- process out materials out of proportion to numbers/biomass

34
Q

removal of keystone species can cause…

A

a community to collapse

35
Q

keystone species increase

A

prey diversity (and overall ecosystem diversity)

36
Q

ecosystem engineers

A

keystone species that affect communities by influencing the structure of a habitat

37
Q

communities are categorized by their…

A

dominant organisms
- (or by physical conditions that affect distribution of species)

38
Q

define community

A

assemblage of species living together in area

39
Q

succession

A

communities change over time

40
Q

community interactions

A

predation, competition, mating

41
Q

most salt tolerant mangroves?

A

landward

42
Q

edge effects

A

important aspect of community structure is the boundary b/w 1 habitat and others

43
Q

2 types of ecotones

A

sharp or flat

44
Q

types of edge effects

A

inherent, induced, narrow, wide, convoluted, perforated

45
Q

wide edge effect

A

substantial distances separates border point where physical conditions and vegetation do not differ from interior patch

46
Q

convoluted edge effect

A

border is non-linear

47
Q

perforated edge effect

A

border has gaps that host other habitats

48
Q

typically there is greater __ ___ where the edge effect occurs

A

species richness

49
Q

___ surveys can demonstrate the existence of an ecotone

A

line-transect

50
Q

__ changes in distribution of species should occur across the ecotone

A

sharp

51
Q

interdependent communities

A

communities in which species depend on each other to exist
- removing a species should cause other species to decline

52
Q

independent communities

A

communities in which species DO NOT depend on each other to exist
- removing a species should cause neutral or positive changes in other species’ fitness

53
Q

community structure

A

species interactions b/w 2 species at a time
- combine species interactions

54
Q

keystone species are usually the…

A
  • top predators
  • ecosystem engineers
55
Q

zonation

A
  • zones w/ diff ranges of environmental conditions and species
  • reflect range of tolerance for species in zones
56
Q

sharp boundaries (ecotones)

A

closed communities

57
Q

indistinct boundaries (ecotones)

A

open communities

58
Q

inherent edge effect

A

natural features stabilize the border location

59
Q

induced edge effect

A

transient, natural, or human-related activities
- subject borders to successional changes over time

60
Q

narrow edge effect

A

one habitat abruptly ends and another begins

61
Q

Clements

A

viewed species in a community as interdependent super organism with distinct ecotones

62
Q

Gleason

A

viewed species as responding idiosyncratically to environmental gradient

63
Q

community concepts: most research supports _____ model

A

Gleason’s individualistic

64
Q

abrupt changes in species distributions may be the result of…

A

abrupt changes in abiotic conditions

65
Q

to plot species evenness (rank-abundance curve)…

A

rank most abundant species (1), next most abundant (2), etc.

66
Q

what is biodiversity? (3 parts)

A

species richness, species abundance, species diversity

67
Q

scales of biodiversity: alpha diversity

A

species biodiversity of local community (natural habitat patch)
- w/in habitat diversity

68
Q

scales of biodiversity: beta diversity

A

number of species 2 communities DO NOT share
- change (or turnover) in species composition b/w 2 distinct communities
- b/w habitat diversity
- highest when habitats vary over fine spatial scales

69
Q

scales of biodiversity: gamma diversity

A

total species richness over a large geographic area such as biome, continent, or ocean basin
-measure of overall diversity for diff ecosystems w/in 1 region

70
Q

Menhinick’s index (D)

A

number of species divided by sqrt (number of individuals in sample)
- the larger the sample, the more species you would expect
- D = s / sqrt(N)
- takes into account richness and evenness

71
Q

species evenness

A
  • quantitative measurement
  • measure of the abundance of individuals in each species
  • free from variations, equal in measure/quantity
72
Q

simpsons index

A

common measure of species diversity; (ranges from 1 –> max number of species in community)
- S = 1/ (summation(p^2))
- s = species richness
- p = relative abundance of each species in community

73
Q

Shannon’s index (H’)

A

H’ = (-) summation (p)(ln p)

74
Q

Simpson’s index: high D value

A

good and means the habitat is diverse, species rich, and able to withstand some environmental impact

75
Q

Simpson’s index: low D value

A

poor and means that habitat is low in species, so a small change to environment would have a serious impact
- ex: pollution

76
Q

can 2 species occupy the exact same niche at the same time?

A

no! because of the competitive exclusion principle (one will be better)

Ecology (33 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions