Download Chp 56 community behavior notes

Chapter 56 - Community Ecology
1) Community- a group of different species living in one area.
2) Species richness (Biodiversity) - The number of species in a community
Increases near equator
3) Relative abundance - population of a given species in a specific size ecosystem
Compares the percent of each species
EX. Percent of mallards in pond compared to total bird population
4) species diversity - Relates the number of species to the “relative abundance” of each
5) Species area affect - Larger areas usually contain more species than smaller ones
Evident on islands
6) Individualistic concept - Community is made of nothing more than different species that
happen to be living in same area
7) Holistic concept (interactive concept) - Communities are an integrated unit that depend on each
other for survival. “super organism”
8) Keystone species - A species that has great influence on
other species in ecosystem. Ex. Sea stars
9) Trophic cascade – There is a ripple effect from one eating
level to another.
Orcas increase
otters decease
Urchins increase
 Kelp decreases
10) Wolf aspen trophic cascade –
11) Community stability - Resistance to change
Biodiversity increases stability
56.2 Ecological Niche Concept
12) Niche - The role an organism fills in its community
13) Niche is determined by:
14) Great horned owl and red tailed hawk have different niches –
Both eat small rodents
Both live in same area
BUT owls hunt _______________ hawks hunt ___________
15) Fundamental niche - Potential niche – without any
competition
16) Realized niche - The part they actually use due to competition. Usually smaller
17) Competition exclusion - One Species is eliminated
from a community because of limited resources.
Cannot occupy same niche
18) Resource partitioning - When several similar species
subdivide a niche for resources
Ex. 5 different warbler species eating different areas of
a tree
19) Character displacement - One Phenotype is selected
because of competition
Ex anoles. on same island there are populations that eat
different things and occupy different niches,
Character displacement can lead to different selection
models
56.3 and 56.4 Symbioses- Animal Interactions
20) Food chain –
21) Food web –
22) Trophic levels = eating level
A) Herbivore –
B) CarnivoreC) Omnivore –
D) Scavenger –
23) Predation- (_________) Predator captures and kills prey
24) Predator adaptations – camouflage, sharp teeth, web, infrared sensors, etc
25) Prey adaptations
a. Camouflage b. Aposematic – Advertise poison or impalatability by coloration
c. Batesian mimicry - A normal species mimics a poisonous one
d. Mullerian mimicry - More than one unpalatable /poisonous species resemble each
other
e. Plant/herbivore interactions –
26) Parasitism- (_________) -Like very slow predation. A parasite will feed on a host but does not
result in immediate death
1. Endoparasites –
Ex. Tape worm, Bacteria, Liver fluke
2. Ectoparasites –
Ex. Ticks, Leeches, Lampreys, mosquitoes
27) Mutualism-(_________) A cooperative relationship where both species benefit
Ex. Acacia trees and fire ants. Acacia trees have thorns that secrete nectar. Ants protect and
defend plant from animals that would eat it
Ex. Pollinators. – Insects, Birds and others
28) Commensalism-(_________) Benefits one species with little or no effect on the other
Ex. Birds follow army ants to find food
Ex. Cape buffalo - stirs up the insects and the egrets can then feed on them
29) Competition-(__________)
See 56.2 Only one organism will win right to mate
30) Competition exclusion - One Species is eliminated from a community because of limited
resources. Both cannot occupy same niche
56.5 Ecological Succession
1. Succession -.
2. Primary succession - The development of
a community in an area that has not
supported life previously.
3. Primary succession occurs on:
bare rock, After volcanic eruptions, sand dunes
Very SLOW – few minerals available can take 100s of years
4. Stages of primary succession:
lichens  ______________ _______________  ______________ _________________
1) Lichens – mutualism between fungi and algae or cyanobacteria.
Fungi protect, algae provides food by photosynthesis. Acids from Lichens turn rock to soil
(chemical weathering). Lichens eventually die and become part of soil
2) Mosses – Need a little soil. Can also grow on dirty rock
3) Grasses – Need thin layer of soil
4) Shrubs – Need thick layer of soil
5) Trees – Need established thick soil layer
5. Secondary succession- Occurs when an existing community has been cleared such as
forest fire, land slide, hurricane
6. Climax community – Stable end of succession. High bio diversity. High relative abundance
7. Eutrophication – “good eating” -The slow process of a lake ecosystem dying due to over
growth of algae which kills other plants beneath and then the fish and animal life