Ch 18 Ecology Cain, Bowman, Hacker Detail

Front 1

Community Membership
Concept 18.1
Species richness differs among ____ due to variation in _____ ___ ____, _____ ____, and _____ ______.

Back 1

communities
regional species pools,
abiotic conditions, and
species interactions.

Front 2

The distributions and abundances of organisms within communities are dependent on 3 factors:
(I) ____ _____ ____ and _____ ______ (____ _____),
(II) _____ _____, and
(III) _____ ______.

Back 2

(I) regional species pools and dispersal ability (species supply), (II) abiotic conditions, and
(III) species interactions.

Front 3

18.1
I. Species _____ is the "first cut" to ______ ______

Back 3

supply
community membership

Front 4

18.1 (I)
The regional pool of species provides an ____ _____ _____ on the #s & types of species that can be present within communities.

Back 4

absolute upper limit

Front 5

18.1 (I)
Humans have greatly expanded the regional species pools of communities by serving as _____ of _____.

Back 5

vectors of dispersal
(e.g. ballast water carried by ships)

Front 6

18.1 (I)
Humans are vectors for _____ _____.

Back 6

Invasive Species.

Front 7

18.1
(II) Abiotic conditions play a strong role in ______ community membership

Back 7

limiting

Front 8

18.1 (II)
[...] many examples...that demonstrate how _____ constraints can control the ____ and _____ of species.

Back 8

physiological
distributions
abundances

Front 9

18.3
(III) Who you ____ with makes all the difference in community membership
(____ _____)

Back 9

interact
(species interactions)

Front 10

18.1
The regional species pool and the ______ ______ of species play important roles in supplying species to communities.

Back 10

dispersal abilities

Front 11

18.1
Humans have greatly expanded the ______ ______ ____ of communities by serving as _____ for the dispersal of _________species.

Back 11

regional species pools
vectors
non-native

Front 12

18.1
______ _______ imposed by abiotic conditions act as a strong “filter” for community membership.

Back 12

Physiological constraints

Front 13

18.1
When species depend on other species for their _____, __________, and _______, those other species must be present if they are to gain membership in a community.

Back 13

growth,
reproduction,
survival

Front 14

Species may be excluded from communities by _________, _______, ________, or _____.

Back 14

competition,
predation,
parasitism,
disease.

Front 15

18.1
Two schools of thought on how species coexist in a community:

Equilibrium theory-________________________________
Non-equilibrium theory-
____________________________

Back 15

ecological & evolutionary compromises lead to resource partitioning. (biotic determinants)

fluctuating conditions keep dominant species from monopolizing resources.
(abiotic determinants of diversity)

Front 16

Resource Partitioning
Concept 18.2
Resource partitioning among the species in a community _______ competition and ________ species richness.

Back 16

reduces
increases

Front 17

18.2
Resource partitioning is an ______ _______ predicting that species must use slightly different resources along a _____ ______ if they are to avoid ______ _______.

Back 17

equilibrium theory
resource spectrum
competitive exclusion.

Front 18

18.2
The ____ overlap, the more ____ between species, with the extreme being ____ overlap and _____ _____.

Back 18

more overlap,
the more competition
complete overlap
competitive exclusion.

Front 19

18.2
the ____ overlap, the _____ specialized species have become on that spectrum, and the ____ strongly they will compete with one another.

Back 19

less overlap, the more specialized
less strongly

Front 20

18.2
____ generalization, ____ overlap
Species are ____ and compete with one another, but that competition keeps their population sizes _____, allowing ____ species in the community.

Back 20

High generalization, high overlap

generalists (their resource use overlaps)

small, allowing more species

Front 21

18.2
The _____ ____ _______ posits that species that use the same set of resources are able to partition them by using them in different proportions.

Back 21

resource ratio hypothesis

Front 22

18.2
Bird Species Diversity Is _____ in More Complex Habitats
(MacArthur and MacArthur)

Back 22

Higher

Front 23

18.2
The theory of resource partitioning relies on the assumption that species have reached a _____ _____ _____ (the _____ ____) and that resources are ______.

Back 23

stable population size
(the carrying capacity)
resources are limiting.

Front 24

Non-equilibrium Theories
Concept 18.3
Nonequilbrium processes such as __________, ____, and _______ can ______ resource availability, thus affecting species interactions and coexistence.

Back 24

disturbance,
stress,
predation
mediate resources availability,

Front 25

18.3
The Outcome of Competition under Equilibrium vs. Nonequilibrium Conditions
(A) Under ______conditions, species 1 (the dominant competitor) out-competes species 2 when it reaches its own carrying capacity (K)
(Huston 1979)

Back 25

equilibrium

Front 26

18.3
The Outcome of Competition under Equilibrium vs. Nonequilibrium Conditions
(B) If nonequilibrium processes such as disturbance, stress, or predation _____ the population of species 1, it will never reach (K) and will not out-compete species 2.
(Huston 1979)

Back 26

reduce

Front 27

18.3
Nonequilibrium theories are ____ to resource partitioning.
....As long as conditions in the lake ____ before the competitively superior species reached its ____ ____, ____ would be possible.
(Hutchinson 1961?)

Back 27

alternatives
changed
carrying capacity
coexistence

Front 28

18.3
Hutchinson hypothesized that the conditions in the lake changed _____ and over ____ periods, which kept any one species from outcompeting the others.

Back 28

seasonally & over longer periods

Front 29

18.3
Hutchinson's model has 2 components:

Time required for one species to exclude another (Tc), which depends on the ______ _____ _____ of the two species.
Time it takes environmental _____to act on population growth of the two species (Te).

Back 29

population growth rates
variation

Front 30

18.3
Hutchinson predicted that when competitive exclusion occurs more rapidly than environmental conditions can change (T_ __ T), coexistence cannot be achieved.

Back 30

(Tc << Te)

Front 31

18.3
...in a fluctuating environment to which the competitors are adapted (where T_ __ T_), environmental variation does not affect the competitive interactions, and competitive exclusion occurs.

Back 31

(Tc >> Te)

Front 32

18.3
Hutchinson argued that it is only when the time it takes for competitive exclusion to occur is ____ _____ to the time it takes for environmental variation to interrupt the competitive interaction (when T_ _ T_) that competitive exclusion is thwarted and coexistence occurs.

Back 32

roughly equal
(Tc=Te)

Front 33

18.3
If Tc << Te, coexistence ______ __ achieved.

Back 33

cannot be
This could occur in environments with little variability, or if the dominant species had very fast growth rates.

Front 34

18.3
In a ____ environment, Tc >> Te, ____ ____ can occur.

Back 34

fluctuating environment
competitive exclusion can occur.

Front 35

18.3
Paine's work stimulated research on the ____ ____ _____,
first proposed by Connel (1978):
Species diversity should be highest at ________________.

Back 35

intermediate disturbance hypothesis,
intermediate levels of disturbance.

Front 36

18.3
At ____ levels of disturbance, competition would determine diversity.
At ___ disturbance levels, many species would ___________.

Back 36

low
high disturbance lvls,
many spec. not able to survive.

Front 37

18.3
At ___ disturbance levels, competitive exclusion reduces diversity.

Back 37

low

Front 38

18.3
At intermediate disturbance levels,
a ____ between disruption of competition and mortality leads to _____ ______.

Back 38

balance
high diversity.

Front 39

18.3
At ___ disturbance levels, diversity declines as mortality rises.

Back 39

high

Front 40

18.3
The intermediate disturbance hypothesis states that intermediate levels of disturbance promote species diversity by reducing _______ ________. Species diversity is low at low levels of disturbance due to competitive exclusion and at high levels of disturbance due to high mortality.

Back 40

competitive exclusion

Front 41

18.3
Huston (1979) added ____ ______: the growth rate of the strongest competitors in a community. It is dependent on the productivity of the community

Back 41

competitive displacement

Front 42

18.3
His (Huston) ____ _____ _____ considers how disturbance frequency and the rate of competitive displacement combine to determine species diversity.

Back 42

dynamic equilibrium model

Front 43

18.3
Species diversity is ___ when disturbance and competitive displacement are both low to intermediate.

Back 43

highest

Front 44

18.3
Species diversity is ___ when competitive displacement is high and disturbance is low.

Back 44

lowest

Front 45

18.3
Species diversity is _____ when disturbance is high and competitive displacement is low.

Back 45

lowest

Front 46

18.3
When both process are ____, species diversity is ____.

Back 46

high,
low.

Front 47

18.3
The Dynamic Equilibrium Model
This model predicts that species diversity will be highest when the level of disturbance and the rate of competitive displacement are _____ to ______.

Back 47

low to intermediate.

Front 48

18.3
The dynamic equilibrium model predicts that species diversity will be highest when the level of disturbance and the rate of competitive displacement are _____ _______.

Back 48

roughly equivalent.

Front 49

18.3
________ _________ can promote species diversity, particularly at intermediate to high levels of disturbance, stress, or predation.

Back 49

Positive interactions

Front 50

18.3
______ ________ assume that resources made available by disturbance, stress, or predation are captured at random by recruits from a larger pool of colonists, all of which have an equal chance to do so.

Back 50

Lottery models

Front 51

The Consequences of Diversity
Concept 18.4
Experiments show that species diversity is positively related to ________ _______..

Back 51

community function.

Front 52

18.4
Relationships between species diversity and community function are ______

Back 52

positive

Front 53

18.4
Species richness is positively related to community ______
the tendency of a community to remain the same in structure and function.

Back 53

stability

Front 54

18.4
Complementarity hypothesis:
As species richness increases, there will be a ____ _____ in community function.
Each species added has an ____ ______.

Back 54

linear increase
equal effect.

Front 55

18.4
Redundancy hypothesis:
The functional contribution of additional species reaches a _____. As more species are added, there is ____ in their function, as redundancy among species.

Back 55

threshold.
overlap

Front 56

18.4
Driver & passenger hypothesis:
Strength of ecological function varies greatly among species. "Driver"species have a _____ effect, "passenger" species have a ______ effect.

Back 56

large
minimal

Front 57

18.4
A variation on the driver & passenger hypothesis:
It assumes there could be _____ between driver and passenger functions.

Back 57

overlap

Front 58

18.4 Plant Cell Wall Conundrum
_____ is commonly made from corn grains that are fermented and distilled.
The energy costs associated with growing the grain and producing the ethanol are ____, so there is only a _____ energy gain in ethanol production.

Back 58

ethanol
high,
slight