Download 17-Experiments

Second Exam
One week from today
Chapters 10, 11, 12, 13, 14, and 15 (most)
Can humans share spaceship earth?
Why Can't We Humans Share Spaceship Earth?
The Vanishing Book of Life on Earth
Watch Average Temperatures 1884-2012
Global Warming
Watch Domino Effects
Intelligent Design?
Space Travel
Agriculture
Economics
Also Handouts
5, 6, and 7
Partial derivatives, ∂Ni/∂Nj sensitivities of each species to changes in
the density of each other species
Jacobian matrix (community matrices)
Lyapunov stability (negative leading dominant eigenvalue)
The ecological niche, function of a species in the community
Resource utilization functions (RUFs)
Competitive communities in equilibrium with their resources
Within & between phenotype components of niche breadth
Hutchinson’s n-dimensional hypervolume concept
Fundamental and Realized Niches
Niche dimensionality, unidimensional shadows misleading
Niche overlap hypothesis
Resource matrices
Resource matrices of utilization coefficients (or electivities)
Disjunct, Abutting, Overlapping, Included Niches
Niche overlap hypothesis
Niche dynamics and niche dimensionality, diffuse competition
Complementarity of niche dimensions
Independence of niche dimensions
Unidimensional estimates of true multidimensional utilization
Niche Breadth: Specialization versus generalization.
Similar resources favor specialists, different resources favor generalists
MacArthur “Economics of Consumer Choice”
Robust theorem: Diets contract when prey abundant
MacArthur and Levins limiting similarity model
Ambush versus Active Foragers: optimal foraging
Compression Hypothesis
Fisher’s model of adaptation and deterioration of environment, p. 92
Periodic tables of niches
Thermoconformer versus thermoregulator continuum
Ecological Equivalents, convergent evolution
Adaptive Suite of horned lizards
Convergent evolution, ecological equivalents (Moloch horridus)
Ten Morphometrics
Snout-vent length
Tail length
Head length
Head width
Head depth
Jaw length
Forefoot length
Foreleg length
Hindfoot length
Hindleg length
Multivariate techniques (principal components, ordination)
Principal Components Analysis
Reduces dimensionality (correlated data)
Changes coordinate system (data positions unchanged)
Log transform data
First Principal Component
Second Principal Component
First Two Principal Components reduce variance by 92.4%
First Two Principle Components reduce variance by 92.4%
First Two Principal Components capture 92.4% of variance
Agama
Page 343
Moloch
Phrynosoma
http://www.digimorph.org/specimens/Moloch_horridus/whole/
Experimental Ecology
Controls
Manipulation
Replicates
Pseudoreplication
Rocky Intertidal Space Limited System
Paine’s Pisaster removal experiment
Connell: Balanus and Chthamalus
Menge’s Leptasterias and Pisaster experiment
Dunham’s Big Bend saxicolous lizards
Brown’s Seed Predation experiments
Pisaster
R. T. Paine
(1966)
Thais
Chiton
Limpet
Mytilus
Semibalanus
Mitella
Joseph Connell
(1961)
Bruce Menge
(1972)
Leptasterias
Menge 1972
Bruce Menge
Grapevine Hills, Big Bend National Park
Sceloporus merriami
Urosaurus ornatus
Arthur Dunham
Six rocky outcrops: 2 controls, 2 Sceloporus removal
plots and 2 Urosaurus removal areas.
========================================
4 year study: 2 wet and 2 dry: insect abundances
Monitored density, feeding success, growth rates, body weights, survival, lipid levels
Urosaurus removal did not effect Sceloporus density
No effects during wet years (insect food plentiful)
Insects scarce during dry years: Urosaurus growth and survival
was higher on Sceloporus removal plots
James Brown
Experimental Design of Seed Predation in the Chihuahuan Desert
___________________________________________________
Plots
Treatments
___________________________________________________
11,14 Controls
6,13
Seed addition, large seeds, constant rate
2,22
Seed addition, small seeds, constant rate
9,20
Seed addition, mixed seeds, constant rate
1,18
Seed addition, mixed seeds, temporal pulse
5,24
Rodent removal, Dipodomys spectabilis (largest kangaroo rat)
15,21 Rodent removal, all Dipodomys species (kangaroo rats)
7,16
Rodent removal, all seed-eating rodents
8,12
Pogonomyrmex harvester ants
4,17
All seed-eating ants
3,19
All Dipodomys plus Pogonomyrmex ants
10,23 All seed-eating rodents plus all seed-eating ants
___________________________________________________________
Munger, J. C. and J. H. Brown. 1981. Competition in desert rodents: an experiment
with semipermeable enclosures. Science 211: 510-512.
open circles =
rodents removed
solid circles =
controls
Defaunation Experiments
in the Florida Keys
Islands of Mangrove trees
were surveyed and numbers
of arthropods recorded.
Islands were then covered
in plastic tents and fumigated
with methyl bromide.
Islands were then resurveyed
at intervals to document the
process of recolonization.
Simberloff and Wilson (1970)
Simberloff and Wilson 1970
Evidence for Stability of Trophic Structure? First number is the number
of species before defaunation, second in parentheses is the number after
_____________________________________________________________________________
Trophic Classes
____________________________________________________________
Island
H
S
D
W
A
C
P
?
Total
_____________________________________________________________________________
E1
9 (7) 1 (0)
3 (2)
0 (0)
3 (0)
2 (1)
2 (1)
0 (0)
20 (11)
E2
11 (15) 2 (2)
2 (1)
2 (2)
7 (4)
9 (4)
3 (0)
0 (1)
36 (29)
E3
7 (10) 1 (2)
3 (2)
2 (0)
5 (6)
3 (4)
2 (2)
0 (0)
23 (26)
ST2
7 (6) 1 (1)
2 (1)
1 (0)
6 (5)
5 (4)
2 (1)
1 (0)
25 (18)
E7
9 (10) 1 (0)
2 (1)
1 (2)
5 (3)
4 (8)
1 (2)
0 (1)
23 (27)
E9
12 (7) 1 (0)
1 (1)
2 (2)
6 (5)
13 (10) 2 (3)
0 (1)
37 (29)
Totals 55 (55) 7 (5) 13 (8)
8 (6) 32 (23)
36 (31) 12 (9)
1 (3) 164 (140)
_____________________________________________________________________________
H = herbivore
S = scavenger
D = detritus feeder
W = wood borer
A = ant
C = carnivorous predator
? = undetermined
E. O. Wilson (1969)
Experimental Ecology
Controls, replicates, treatments, pseudoreplication
Marine rocky intertidal, space-limited systems
Joe Connell, barnacles, Balanus and Chthamalus
Bob Paine, mindless experiments, Pisaster removal, keystone predator
Bruce Menge, removal + addition experiment with sea stars
Art Dunham, Big Bend Grapevine hills, lizard removal experiments
Jim Brown, New Mexico seed eating ants and rodents
2 replicates for each of 12 treatments
(including 11 manipulations plus 2 controls).
Short term: ants and rodents compete for seeds
Large seeded plants versus small seeded plants
Long term: indirect mutualism, facilitation between ants and rodents
Simberloff and Wilson’s defaunation experiments in Florida keys
Non-interactive, interactive, assortative, and evolutionary equilibria