Brainscape's Knowledge GenomeTM

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


See full index

BIOL 360 - General Ecology > Community (Diversity, Structure, Disturbance) > Flashcards

Community (Diversity, Structure, Disturbance) Flashcards

1
Q

Disturbance

A

an event of intense environmental stress occurring over a relatively short period of time and causing large changes in the affected ecosystem

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

Intermediate disturbance hypothesis

A

Species diversity will be highest in communities that experience intermediate levels of disturbance

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

Community

A

an association of interacting species inhabiting some defined area

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

Community structure

A

Based on the INTERACTIONS of all species in a community.

How abiotic & biotic factors influence the number of species, relative abundance of species, and the types of species in an area

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

Guild

A

One type of organism that make their living the same way

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

How abundant are most species?

A

Moderately abundant.

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

Species richness

A

Number of species in a community

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

Species evenness

A

Relative abundance of species

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

What are metrics we can use to describe community diversity?

A

(1) Species richness
(2) Species evenness
(3) Shannon-Wiener index (H’)
(4) Simpson Index (y)
(5) Rank-Abundance Curve

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

Shannon-Wiener Index

A

H’ increases with increasing richness and evenness

H’ = - Σplnp

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

Simpson Index

A

y is the probability that any two individuals drawn from a community will be of the same species. (0 = high diversity)

y = Σp^2

D = 1 –Σn(n-1)/N/(N-1)

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

Rank-abundance curve

A

Plots proportional abundance (y) relative to abundance rank (x). Lower slope = greater evennes.

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

What are factors that influence community diversity?

A

(1) Environmental complexity
(2) Species interactions
(3) Disturbances

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

What can increase community diversity?

A

(1) Increasing environmental complexity (heterogeneity=more niches)
(2) Predation and competition (greater partitioning of resources/space)
(3) Intermediate disturbance

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

Compare community diversity with community structure

A

Community diversity = # different species in a community.

Community structure = interactions of all species in a community

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

Primary producers

A

Chemo/photoautotrophs

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

Primary consumers

A

Herbivores that eat primary producers

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

Secondary consumers

A

Carnivores that eat primary producers

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

Tertiary consumers

A

Carnivores that eat other carnivores

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

Food web

A

Diagram showing feeding relationships among organisms within an ecosystem

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

What is the relationship between the number of feeding interaction between species with the overall diversity of the community?

A

feeding interactions is INDEPENDENT of the overall diversity of the community.

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

What is the relationship between the number of trophic levels between species with the overall diversity of the community?

A

trophic levels increases with species richness. So higher community diversity is associated with increased food web complexity.

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

How are food webs and community diversity related?

A

Diversity is independent from the # of feeding interactions, but the #trophic levels (food web complexity) tends to increase with community diversity.

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

Connectedness web

A

Shows feeding relationships among organisms

25
Q

Energy flow web

A

Shows connections quantified as energy flux

26
Q

Functional web

A

Emphasize the influence of populations on growth rates of other populations

27
Q

Food webs are defined in terms of…?

A

(1) Feeding interactions

(2) #trophic levels

28
Q

What are indirect interactions of food webs?

A

(1) Indirect commensalism
(2) Apparent competition
(3) Trophic cascades

29
Q

Indirect commensalism

A

Activities of one species indirectly benefit another species without itself being harmed or helped

30
Q

Apparent competition

A

when negative impacts on species increase due to two species sharing a predator, or by one species facilitating the population growth of a predator for the other species.

31
Q

What are the types of trophic cascades?

A

(1) Bottom-up

(2) Top-down

32
Q

Keystone species

A

species whose interactions (usually feeding) have a disproportionately large influence on the structure of their community.

33
Q

Altered stable state

A

Results from the loss of a habitat’s keystone species. Altered stable state is a habitat’s shift from an established community structure to a new one.

34
Q

What is the impact of introduced/invasive species on community structure?

A

Simplifies community structure complexity by eliminating trophic levels. Diversity (α) isn’t decreased at the site, but diversity between sites (β) is decreased.

35
Q

What are the energy flow constraints of energy transfer through the food web?

A

(1) Limited assimilation
(2) Respiration
(3) Heat loss

36
Q

Assimilation (growth) efficiency

A

Percentage of what is initially consumed that becomes incorporated into the consumer

37
Q

About ___% of biomass is lost when transferred from between trophic levels. The ecological efficiency is ___%.

A

90%; 10%

38
Q

As trophic levels increase, biomass ___.

A

Decreases.

39
Q

The most productive ecosystems have a maximum of ___ levels.

A

6.

40
Q

What are the types of disturbances?

A

Source: Natural vs Anthropogenic
Space: Small vs Large

41
Q

What kind of species will thrive under conditions of HIGH disturbance?

A

Weedy, fast growing

42
Q

What kind of species will thrive under conditions of LOW disturbance?

A

Competitively superior/dominant

43
Q

What kind of species will thrive under conditions of MEDIUM disturbance?

A

Balance–diversity of species

44
Q

What are the types of succession?

A

(1) Primary - new substrate

(2) Secondary - old substrate available

45
Q

Primary succession

A

Community development on new or newly exposed geological substrate.

46
Q

Secondary succession

A

Community development after a disturbance removes the community of organisms but not the soil and organics.

47
Q

Pioneer species

A

Early successional species. The first species to colonize an open area after a disturbance. These species tend to be hearty plants with N2-fixing bacteria and deep roots.

48
Q

Climax species

A

Late successional species. the last assemblage of species to establish themselves in a habitat. The community remains in a stable state until a disturbanceresets the system. These species tend to be slow-growing, long-lived, and highly efficient competitors.

49
Q

How long does succession take?

A

Depends on (1) type and (2) composition of community

50
Q

What are some mechanisms of succession?

A

(1) Facilitation
(2) Inhibition
(3) Tolerance

51
Q

Facilitative succession

A

Pioneer species are the only ones capable of colonizing during early stages of succession. They modify their environment so that it becomes less suitable for them, but more suitable for later successional species.

52
Q

Inhibitive succession

A

Earlier occupants of an area modify the environment in a way that makes it less suitable for both early and late successional species. Late successional species can only get a foothold in an area if space is opened up by the death of earlier successional species. Late successional species eventually dominant because they are long-lived and are able to resist biotic and physical stress that wipes-out earlier successional species.

53
Q

Tolerance

A

all species tolerant of the conditions in a particular environment (even climax species) can be present in pioneer community. Final composition reflects the environment’s selection.

54
Q

What are the systems/patterns of disturbance?

A

Autogenic (stable, biotic) vs allogenic (unstable, abiotic) succession

55
Q

Autogenic succession

A

Biotic elements of a community are driving succession to a stable, unchanged equilibrium

56
Q

Allogenic succession

A

Abiotic elements (disturbances, weather) prevent a community from reaching equilibrium

57
Q

Resistance

A

the ability of a community to maintain

structure/function in the face of disturbances,

58
Q

Resilience

A

the ability of a community to bounce back

after a disturbance.

59
Q

What happens if the underlying environment changes?

A

(1) Environment composition change –> phase shift, change in community composition
(2) Pulse event (predator removal) –> Altered stable state

BIOL 360 - General Ecology (12 decks)

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