Download Chapter 54 - dewhozitz.net

BIOL V03 Lecture: Community Ecology (Campbell10 - Ch 54)
©2014 copyright Marta D. de Jesus
I. in general
A. intraspecific
B. interspecific
1. communities
2. variation
all contain
1) producers
2) consumers
3) recyclers
II. Types of ecological interactions
species 1
-/+
A. competition
1. can be intraspecific or interexamples
2. competitive exclusion principle
a. modelled (Lotka & Volterra
b. tested (Gause 1934)
3. ecological niche
a. includes habitat
b. other components
c. fundamental niche vs.
c. realized niche
eg: barnacles
4. resource partitioning
eg: different Anolis lizards
5. character displacement
eg: bill sizes of Darwin’s finches
B. predation, herbivory, parasitism & disease
+
1. lots of examples
2. predator adaptations
2 major strategies
3. prey defenses
a. behavioral
b. morphological
1) plants
2) animals
mechanical
coloration or patterning
- mimicry can also be used by predators
c. chemical: toxins or distasteful
species 2 (host)
-
-
eg: monarchs
4. parasitism
a form of symbiosis
eg: tracheal mites
C. mutualism
+
+
symbiosis & benefitting each other
eg. bullhorn acacia & protector ant
others we’ve discussed
1) Rhizobium bacteria & legume plants
2) digestion of cellulose in large mammals by gut microbes
3) some sea anemones & corals have zooxanthellae
4) mycorrhizae & plants
D. commensalism
+
0
symbiosis; 1 benefits, other not bothered
eg: cattle egrets & water buffalo
eg: epiphytic plants
E. neutral
0
0
2 species living in same area don’t affect/interact with each other; rare
F. facilitiation: one species positively affects another without close contact
eg: black rush (Juncus) helps change soil so other plants benefit
G. coevolution
eg: bullhorn acacias & ants
III. Species richness/diversity: what can effect this?
A. 2 component
1. species richness
2. relative abundance
3. now often using molecular biology/DNA testing to help illuminate
B. trophic structure
1. food chains
a. producers
b. consumers
1) 1˚ = herbivores
2) 2˚ = carnivores
3) omnivores
c. often not put in, but also present: recyclers
1) detritivores
2) decomposers
2. food webs
3. have limited length of steps, why?
a. energetic hypothesis
b. dynamic stability hypothesis
C. important species in the community
1. dominant species
2. keystone species
eg: Pisaster & mussels
eg: sea otters & kelp (before & after Orca predation
3 foundation species
eg: beavers
eg: moose
4. invasive species
D. control of relationships
1. bottom-up model
2. top-down model
3. lots of other models:
eg: reciprocal
eg: alternating
4. dynamic/changing process
IV. Disturbance
A. “balance of nature”
B. disturbance
eg: prairie fire
C. ecological succession
1. trends
2. kinds (large areas)
a. primary succession
pioneer community
b. secondary succesion
3. climax community
V. Biogeographic factors
A. center of origin
B. range
1. endemic
2. cosmopolitan
C. equatorial-polar gradients (Darwin & Wallace)
key: “evapotransporation”
D. area effects (von Humboldt)
E. island equilibrium model (Wilson & MacArthur)
1. size of an island
2. distance from mainland
F. ecotones
G. humans as a homogenizing force