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Community Ecology: Species Interactions. 1. XXXXXXXXXX. ?. 2. Competition is important...just not as important as predation (sometimes). 5 Basic types of species interactions. Food Habitat Nutrients. Competition ...common use of a limited resource. limited. What can be limiting....?.
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1 XXXXXXXXXX ? 2 Competition is important...just not as important as predation (sometimes) 5 Basic types of species interactions
Food Habitat Nutrients Competition ...common use of a limited resource limited What can be limiting....?
Between and within species?? Intraspecific competition Interspecific competition
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. (-) B A (-)
(-) B A (-) + + - - R 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.
Apparent competition - occurs indirectly between two species which are both preyed upon by the same predator. B A B A - - - - + + + P P
http://video.google.com/videoplay?docid=-6431936272692514162
FUNDAMENTAL REALIZED A B The Niche Concept food Temperature Daphnia density habitat pH Salinity 2 dimension, but there are more....
The Niche Concept • Sharing of resources alone not evidence of competition • Niche overlap correlates with competition Largemouth bass Prey Weight (Relative) Green Sunfish Bluegill Temperature (Celsius)
Resource partitioning Population Abundance Resource Gradient Competition's role in ecology and evolution "species packing" Population Abundance Resource Gradient
Lake Malawi Lake Tanganyika 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
Examples: Classic Werner and Hall Experiments Bluegill Green Sunfish Pumpkinseed
Population Abundance Time How do we see it or measure it? • Individual Responses • Behavior – feeding rate • Physiology – growth rate • Morphological – body size • Population responses • Abundance • Distribution
Population Abundance Time Modeling Competition • Lotka-volterra model • Competition coefficients • The equations • What the hell is an isocline, anyway? • 4 graphs. See Molles
Exotic Species Exotic Species: A species not in its native range Invasive/Nuisance Species: An exotic species that meets 3 criteria
Invasive fishes 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
Non-fish Invasive Species that affect the ecology of native Wisconsin Fishes Pelagic Planktivore: Spiny Water Flea Benthic Filter Feeder: Zebra Mussel, Quagga Mussel Plant: Eurasian Water Milfoil
Exotic fishes utilize different habitats And a variety of food sources
How do they get here? People Ships ballast water Canals Aquaculture
Aquaculture Silver carp Bighead carp Ballast water Alewife White Perch Round goby Spiny Water Flea Zebra Mussel Quagga Mussel Intentional Stocking Pacific Salmon Brown trout Rainbow trout Common carp Rainbow smelt Canals Sea lamprey Rainbow smelt
4 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 Lack of a natural predator
Questions Researchers Ask • Impact • Distribution Forecasting • Prediction/Prevention • Control
Detrimental to sport fisheries... round gobies to smallmouth bass nests http://www.glwi.uwm.edu/people/jjanssen/goby/index.html
Detrimental to ....life as we know it on all lakes and rivers http://www.youtube.com/watch?v=2ChwJiKKBdA