Important Points - | Department of Zoology at UBC
24
1 Important Points Midterm 2 is Tuesday the 3 rd (this coming Tuesday)
Transcript of Important Points - | Department of Zoology at UBC
1
Important PointsMidterm 2 is Tuesday the 3rd (this coming Tuesday)
2
Main Points1) Factors controlling population growth and size
2) Top-down versus bottom-up regulation of populations--Serengeti example--the phenomenon of migration--northern BC example
3) Competition--intra vs. interspecific--apparent vs. exploitative vs. interference--ecological vs. evolutionary effects--null models and limitations of experiments
4) Terms: Allee effect, apparent competition, experiment (press vs. pulse), fundamental niche, realized niche
3
Population Growth Review
4
Negative vs. Positive Density-Dependence
population size
# ki
ds s
urvi
ving
/ in
d
5
Negative vs. Positive Density-Dependence
population size
# ki
ds s
urvi
ving
/ in
d
population size
6
Negative vs. Positive Density-Dependence
population size
Allee effect = positive correlation between populationdensity and the per capita rate of population growth
# ki
ds s
urvi
ving
/ in
d
population size
7
Density-Dependent Factors 1) Competition
2) Predation
3) Disease/Parasites
8
Density-Dependent Factors 1) Competition
2) Predation
3) Disease/Parasites
Density-Independent
1) Natural disasters
(rain, drought, etc.)
9
Experiments in EcologyExperiment = a test under controlled conditions
made to examine the validity of a hypothesis.
10
Experiments in EcologyExperiment = a test under controlled conditions
made to examine the validity of a hypothesis.
Pulse experiment = manipulation is applied once, then the response of the system (e.g., abundance, distribution, diversity) is measured.
11
Experiments in EcologyExperiment = a test under controlled conditions
made to examine the validity of a hypothesis.
Press experiment = manipulation is applied continually, then the response of the system (e.g., abundance, distribution, diversity) is measured.
12
Top-down versus bottom-up control
13
Top-down versus bottom-up control• Example: increased mortality of Serengeti ungulates (Sinclair et
al. 2003)
14
Top-down versus bottom-up control
15
= 1967-1980 (predators not poached)
= 1981-1987 (predators poached)
= 1988-2001 (predators not poached)
Top-down versus bottom-up control
16
= 1967-1980 (predators not poached)
= 1981-1987 (predators poached)
= 1988-2001 (predators not poached)
Top-down versus bottom-up control
17
= 1967-1980 (predators not poached)
= 1981-1987 (predators poached)
= 1988-2001 (predators not poached)
Top-down versus bottom-up control
18
= 1967-1980 (predators not poached)
= 1981-1987 (predators poached)
= 1988-2001 (predators not poached)
Top-down versus bottom-up control
19
Migration Systems
Characterized by:
1) Resources that varyin time
2) Synchronized births
20
Synthesis: top-down control, Allee effects, and apparent competition
From Wittmer et al. 2007
21
Synthesis: top-down control, Allee effects, and apparent competition
22
Synthesis: top-down control, Allee effects, and apparent competition
_ _
_
23
CompetitionInterference competition = negative interaction
between pairs of species, where one species directly inhibits another from consuming a resource
_
_
24
CompetitionExploitative competition = negative interaction
between pairs of species, routed through a resource
_ _
_
_
![Making maps, many maps! [What is GIS?] Dr. Brian Klinkenberg Department of Geography, UBC For Zoology 502 March 9, 2008 Why do I want to know where they.](https://static.fdocuments.net/doc/165x107/56649d025503460f949d5a10/making-maps-many-maps-what-is-gis-dr-brian-klinkenberg-department-of.jpg)
