Transcript Competition Extinction Exotics

5 Basic types of species interactions
1XXXXXXXXXX
?
2
Competition is important...just not as
important as predation
Competition ...common use of a limited resource
limited
What can be limiting....?
food
habitat
food
FUNDAMENTAL
REALIZED
A
B
habitat
2 dimension, but there are more....
Between and within species??
Intraspecific competition
Interspecific competition
Individual Responses
•Behavior – feeding rate
•Physiology – growth rate
Population
Abundance
How do we see it or measure it?
•Morphological – body size
Population responses
•Abundance
•Distribution
Time
3 types of competition??
Interference competition
Exploitation competition
Apparent competition
Interference competition - occurs directly between
individuals via aggression etc. when the individuals
interfere with foraging, survival, reproduction of
others, or by directly preventing their physical
establishment in a portion of the habitat.
A
(-)
(-)
B
Exploitation competition - occurs indirectly through
a common, limiting resource, which acts as an
intermediate. Ex. depletes the amount of food or fill
up all the available space.
A
(-)
(-)
- + +
R
B
-
Apparent competition - occurs indirectly between
two species which are both preyed upon by the same
predator.
B
A
-
P
+
A
+
- -
P
B
+
http://video.google.com/videoplay?docid=6431936272692514162
Competition's role in ecology
and evolution
"species packing"
Population
Abundance
Population
Abundance
Resource partitioning
Resource
Gradient
Resource
Gradient
Lake Tanganyika
Lake Malawi
Cichlids exhibit remarkable evolutionary convergence. Similar ecomorphs have evolved repeatedly within different cichlid
assemblages. All of the cichlids in the left-hand column are from Lake Tanganyika. All of the cichlids in the right-hand
column are from Lake Malawi, and are more closely related to one another than to any species within Lake Tanganyika.
Note the similarities among color patterns and trophic morphologies.
Utilize resources along a gradient (See
Wooton)
– Food particle size
– Temperature
– Habitat
100
90
80
Fish Abundance
70
60
Sculpin
50
Dace
40
30
20
10
0
1
2
3
4
5
6
7
8
9
Station (1=downstream)
10
11
12
Examples: Classic Werner and Hall Experiments
Bluegill
Green Sunfish
Pumpkinseed
Examples: Ciscoes adaptive radiation (Lindsey 1981)
Modeling Competition
Lotka-volterra model
Competition coefficients
The equations
What the hell is an isocline, anyway?
– 4 graphs. See Molles
Population
Abundance
•
•
•
•
Time
Exotics species that affect the
ecology of native Wisconsin Fishes
Pelagic planktivores - Alewife, Rainbow smelt, white perch
Benthic insectivores – round goby, common carp
Pelagic piscivores – Pacific salmon, brown trout
Pelagic/benthic parasite – Sea lamprey
Stream insectivores – brown trout, rainbow trout
Pelagic filter-feeders – silver carp, bighead carp
Exotics fish utilize different habitats
And a variety of food sources
How do they get here?
People
Ships ballast water
Canals
Aquaculture
Ballast water
Alewife
white perch
Round goby
Canals
Sea lamprey
Rainbow smelt
Aquaculture
Silver carp
Bighead carp
Intentional
Stocking
Pacific Salmon
Brown trout
Rainbow trout
Common carp
Rainbow smelt
Species
Earliest Record
Unintentional or Intentional
Transport or Release Mechanism(s)
Alewife
<1953
Unintentional
Canals
American eel
1970
Unintentional
Canals
Atlantic salmon
1972
Intentional
Stocked
Brown trout
1883
Intentional
Stocked
Brook silverside
2002
Unintentional
Unknown
Chinook salmon
1967
Intentional
Stocked
Coho salmon
1966
Intentional
Stocked
Common carp
1897
Intentional
Stocked
Eurasian ruffe
1986
Unintentional
Ballast Water
European flounder
1981
Unintentional
Ballast Water
Fourspine stickleback
1986
Unintentional
Ballast Water or Live Bait
Freshwater drum
?
Intentional
Stocked (assumed)
Gizzard shad
?
Unintentional
Live Bait or Aquaria
Goldfish
1975
Intentional
Stocked (assumed)
Kokanee salmon
?
Intentional
Stocked (assumed)
Pink salmon
1956
Intentional (unplanned)
Stocked
Rainbow smelt
1930
Unintentional
Canals
Rainbow trout
1895
Intentional
Stocked
Round Goby
1995
Unintentional
Ballast Water
Sea lamprey
1938
Unintentional
Canals
Splake
?
Intentional
Stocked
Threespine stickleback
1987
Unintentional
Ballast Water
Tubenose goby
2000
Unintentional
Ballast Water
White Perch
1986
Unintentional
Ballast Water
LAKE
SUPERIOR
3 aspects that make them so successful...?
High fecundity – lots of eggs / individual
Excellent competitors – better at gaining
resources then native species
Exploit a less well used resource
Detrimental to sport fisheries... round
gobies to smallmouth bass nests
http://people.cornell.edu/pages/gbs27/gbssmb.html
Detrimental to ....life as we know it on all
lakes and rivers
http://www.youtube.com/watch?v=2ChwJiKKBdA