Transcript 投影片 1

Chap. 6 Population Ecology (II)
鄭先祐 (Ayo)
國立台南大學 環境與生態學院
2008年2月至6月
Population ecology
1.
2.
3.
4.
5.
6.
Properties of the population
Basic concepts of rate
Intrinsic rate of natural increase
Concept of carrying capacity
Population fluctuations and cyclic oscillations
Density-independent and density-dependent
mechanisms of population regulation
chap.6 population ecology (II)
2
7. Patterns of dispersion
8. The Allee principle of aggregation and refuging
9. Home range and territoriality
10. Metapopulation dynamics
11. Energy partitioning and optimization: r- and Kselection
12. Population genetics
13. Life history traits and tactics
chap.6 population ecology (II)
3
7 Patterns of Dispersion
Patterns of dispersion
Random
Regular (uniform)
Clumped
Regular clumped
Fig 6-22. four basic patterns of
the dispersion of individuals
within a population.
chap.6 population ecology (II)
4
Table 6-2
In all but 3
of 11
quadrates,
spiders
were
randomly
distributed.
chap.6 population ecology (II)
5
8 The Allee Principle of
Aggregation and Refuging
Aggregation
Local habitat or landscape differences
Daily and seasonal weather changes
Reproductive processes
Social attraction
Allee principle of aggregation
 undercrowding or overcrowding may be
limiting
chap.6 population ecology (II)
6
Fig. 6-23. Illustration of the Allee principle.
(A)Growth and survival is greatest when the population size is small.
(B)In an intermediate-sized population being the most favorable.
In the latter instance, undercrowding is as detrimental as overcrowding.
chap.6 population ecology (II)
7
chap.6 population ecology (II)
8
Refuges
 a very successful aggregation strategy has
been termed refuging.
Refuges are site or situations where members of
an exploited population have some favorable
central place or core – for example, a starling
roost or a large breeding colony of sea birds.
Lek (mating arena) (求偶競技場)
 A lek is a gathering of males, of certain animal
species, for the purposes of competitive mating
display.
chap.6 population ecology (II)
9
Relevant to human
The Allee principle is relevant to the
human condition.
Aggregation into cities and urban districts
(a refuging strategy) is obviously beneficial
But only up to a point, in connection with
the law of diminishing returns.
chap.6 population ecology (II)
10
9 Home Range and
Territoriality
 Isolation usually is the result of
1. Competition between individuals for
resources in short supply
2. Direct anagonism, involving behavioral
responses in higher animals and chemical
isolation mechanisms (antibiotics and
allelopathics) in plants, microorganisms, and
lower animals.
 Home range vs. territory
chap.6 population ecology (II)
11
Fig. 6-25. (A)
home ranges of
meadow voles
(Microtus
pennsylvanicus)
in fragmented
and
nonfragmented
habitat patches.
chap.6 population ecology (II)
12
Fig. 6-25. (A)
home ranges of
meadow voles
(Microtus
pennsylvanicus)
in fragmented
and
nonfragmented
habitat patches.
chap.6 population ecology (II)
13
Fig. 6-25 (B) Territories of
song thrushes (Turdus
philomelos) in two
consecutive years.
Note that individuals 1,6,
and 7 maintained the
same territories both
years.
chap.6 population ecology (II)
14
Fig. 6-25 (B) Territories
of song thrushes
(Turdus philomelos) in
two consecutive years.
Note that individuals 1,6,
and 7 maintained the
same territories both
years.
chap.6 population ecology (II)
15
Fig. 6-26. Fitness in terms of body weight gained or lost
daily of territory-holding spiders compared with individuals
unable to establish and hold territories (floaters).
chap.6 population ecology (II)
16
10 Metapopulation Dynamics
Fig. 6-27.
Hypothetical
metapopulation
distribution. Species
may periodically
disappear from lowquality patches.
chap.6 population ecology (II)
17
11 Energy Partitioning and
Optimization: r- and K-Selection
Partitioning or allocation of energy
 Maintenance, Growth, Reproduction
 net energy
 r-selection
 K-selection
chap.6 population ecology (II)
18
Fig. 6-28.
Hypothetical
allocation of
energy to three
major activities
necessary for
survival in four
contrasting
situation (A-D)
where the
relative
importance of
each activity
varies.
chap.6 population ecology (II)
19
Fig. 6-29 Optimization
cost-benefit models (A)
Balancing use of food
sources.
不分好壞食物
找較難找的食物
∆S = energy expended
in searching for a
preferred food item;
∆P = energy expended
in pursuing a particular
food item
chap.6 population ecology (II)
20
Fig. 6-29 (B)
Balancing use of
foraging areas.
∆T = energy
expended on
traveling between
catches;
∆H = energy
expended on
hunting
chap.6 population ecology (II)
21
Fig. 6-29.
Balancing time
spent on
reproduction and
feeding.
chap.6 population ecology (II)
22
Table 6-3
chap.6 population ecology (II)
23
Table 6-4
chap.6 population ecology (II)
24
Fig. 6-31.
Reproductive
effort plotted
against
nonreproductive
biomass in six
populations of
four species of
goldenrods
(Solidago).
chap.6 population ecology (II)
25
12 Population Genetics
Population genetics
Natural selection
Evolution
Adaptation
 refers to traits of an organism that increase
its fitness to survive and reproduce.
Hardy-Weinberg equilibrium law
chap.6 population ecology (II)
26
Hardy-Weinberg equilibrium law
1.
2.
3.
4.
5.
Mating is random
New mutations do not occur
No gene flow
No natural selection
The population size is large
chap.6 population ecology (II)
27
12 Population Genetics
Neutral mutation
Genetic drift
Effective population
Inbreeding
Altruistic behaviors
Eusociality
Kin selection
Inclusive fitness
chap.6 population ecology (II)
28
chap.6 population ecology (II)
29
chap.6 population ecology (II)
30
Fig. 6-35. The
Florida scrub jay
(Apelocoma
coerulescens)
chap.6 population ecology (II)
31
13 Life History Traits and
Tactics
 four life history traits that are key to
survival tactics
1. Brood size
2. Size of young (at birth, hatching, or
germination)
3. Age distribution of reproductive effort
4. Interaction of reproductive effort with adult
mortality (especially the ratio of juvenile to
adult mortality)
chap.6 population ecology (II)
32
Life history theories
1. Where adult mortality exceeds juvenile
mortality, the species should reproduce only
once in a lifetime, where juvenile mortality is
higher, the organism should reproduce several
times.
2. Brood size should maximize the number of
young surviving to maturity averaged over the
lifetime of the parent.
 Ground-nesting birds, clutch size最大
 Nesting in a cavity or other protected place will have
a much smaller clutch size.
chap.6 population ecology (II)
33
3. In expanding populations, selection should
minimize age at maturity (r-selected organisms);
in stable populations, maturation should be
delayed.
4. When there is risk of predation, scarcity of
resources, or both, size at birth should be large;
conversely, size of young should decrease with
increasing availability of resources and
decreasing predation or competition pressure.
chap.6 population ecology (II)
34
5. For growing or expanding populations in
general, not only is the age of maturity
minimized and reproduction concentrated
early in life, but also brood size should be
increased and a large portion of energy flow
partitioned to reproduction – a combination of
traits recognizable as an re-selection tactic.
For stable populations, K-selection.
6. When resources are not strongly limiting,
breeding begins at an early age.
7. Complex life histories enable a species to
exploit more than one habitat and niche.
chap.6 population ecology (II)
35
問題與討論
[email protected]
Ayo 台南站：http://mail.nutn.edu.tw/~hycheng/
chap.6 population ecology (II)
36