Download Ecology - Citrus College

Community
Ecology
Ecology
• The scientific study of the interactions
between organisms and their environments
(abiotic and biotic).
1. Abiotic: non-living factors
(temperature, light, water, and nutrients)
2. Biotic: living factors
(other plants and animals)
Hierarchy of Organization
• Biological organization:
Based on structural levels from Least to
Most Inclusive.
Inclusive
1. Atoms
2. Molecules
3. Organelles
4. Cells
5. Tissues
6. Organs
7. organs systems → The Realm Of Ecology
8. Organisms
• Individuals (species) composed of many
specialized cells.
9. Populations
• Localized groups of organisms belonging
to the same species.
species
• Groups of individuals of the same species
living together.
10. Community
• Populations of organisms living together in
the same environment.
• Four properties:
1. Diversity
2. Prevalent form of vegetation
3. Stability (resist change)
4. Trophic structure (feeding structure)
11. Ecosystem
• Dynamic system of organisms interacting
with each other (biotic) and the inanimate
environment (abiotic).
12. Biomes
• Broad geographic region with a characteristic
array of organisms.
• Examples:
1. Tropical rain forest
2. Desert
3. Chaparral
4. Estuaries
5. Coral reefs
13. Biosphere
• Entire surface of the earth and its organisms.
organisms
Habitat
• The place or region where an organism lives.
Ecological Niche
• An organisms habitat, role, resource
requirements, and tolerance ranges for each
abiotic condition.
Competition
• A form of interaction in which two or more
individuals or species utilize the same limited
resources.
resources
• Two examples:
1. Intraspecific competition
2. Interspecific competition
1. Intraspecific Competition
• Competition within a species for the same
limited resources in the same habitat.
2. Interspecific Competition
• Competition between two or more species
for the same limited resources in the same
habitat.
Competitive Exclusion Principle
• States the following:
1. The concept that two species cannot continue to
occupy the same environmental niche.
2. They would compete for the same limited
resources.
3. One species will use the resources more
efficiently and have a reproductive advantage
that will eventually lead to elimination of the
other species.
Symbiosis
• A form of interspecific interaction in which a
host species and symbiont maintain a close
association.
• Example:
1. Predation
1. Predation
• Where one organism (the predator) acquires
its needed resources by eating another
organism (the prey).
• Predator/prey relationship.
• Example: lynx and snowshoe hare
Question:
• How do some organisms avoid becoming
prey?
prey
• Answers:
1. Camouflage
2. Aposematic
3. Mimicry
1. Camouflage
• Cryptic coloration:
a. Hides from predators.
b. Example: English Peppered Moth
2. Aposematic
• Bright colors
a. Advertises noxious trait
b. Example: Monarch Butterfly
3. Mimicry
• Two examples:
1. Mullerian Mimicry:
Mimicry when two unpalatable
species mimic each other in the same habitat.
2. Batesian Mimicry:
Mimicry palatable species
mimic unpalatable species.
Keystone Predator
• A predator the maintains species diversity in
a community.
• Reduces the density of the strongest
competitors in a community.
• Example:
1. Red-tailed hawk
2. Coyote
3. Harvester ant
Symbiotic Relationships
• Help structure communities.
• Three examples:
1. Parasitism
2. Commensalism
3. Mutualism
1. Parasitism
• Symbiotic relationship which benefits one
organism and harms the other.
other
• Example:
1. Tick on a coyote
2. Tapeworm in a dog
3. Flea on a cat
2. Commensalism
• Symbiotic relationship which benefits one
organism while the other is unaffected.
unaffected
• Example:
1. Cattle egrets and cattle in field
3. Mutualism
• Symbiotic relationship which benefits both
organisms.
organisms
• Examples:
1. Acacia ants and acacia tree
2. Termites and gut protozoa
3. Legumes and nitrogen-fixing bacteria
Ecological Succession
• Transition in species composition over
ecological time.
time
• Three examples:
1. Primary Succession
2. Secondary Succession
3. Climax Community
1. Primary Succession
• Occurs in areas where no community existed
before (first succession).
• Example:
1. New volcanic islands - lichens
2. Secondary Succession
• Occurs in disturbed habitats where some soil,
and perhaps some organisms, still remain after
the disturbance.
disturbance
• Example:
1. Fires
2. Floods
3. Drought
3. Climax Community
• Community that remains essentially the same
over long periods of time.
• It is the final stage of ecological succession.
succession
Trophic Structure
• The different feeding relationships that
determine the route of energy flow and the
pattern of chemical cycling.
• According to the “rules of ten,” approximately
10% of the potential energy stored in the bonds
of organic molecules at one trophic level fuels
the growth and development of organisms at
the next trophic level.
level
Trophic Structure
• Five examples:
1. Primary Producers
2. Primary Consumers
3. Secondary Consumers
4. Tertiary Consumers
5. Decomposers and Detrivores
1. Primary Producers
• Autotrophs: which make up the trophic
level of an ecosystem that ultimately supports
all other levels.
• Examples:
1. Mostly photosynthetic organisms
2. Primary Consumers
• Herbivores:
Herbivores organisms in the trophic level
of an ecosystem that eat plants or algae.
• Examples:
1. Grasshopper
2. Mouse
3. Secondary Consumers
• The trophic level of an ecosystem consisting
of carnivores that eat herbivores.
herbivores
• Examples:
1. Snake
2. Green sunfish
4. Tertiary Consumers
• The trophic level of an ecosystem consisting
carnivores that eat other carnivores.
carnivores
• Examples:
1. Hawks
2. Mountain lions
5. Decomposers and Detrivores
• Heterotrophs that get their nutrition by
breaking down the organic compounds
found in waste organic matter and dead
organisms.
organisms
5. Decomposers and Detrivores
• Examples:
A. Decomposers: 1. Bacteria
2. Fungi
B. Detrivores:
1.
2.
3.
4.
5.
6.
Worms
Nematodes
Insects
Lobsters
Shrimp
Condors
Trophic Structure
Tertiary Consumer: snake (10 KCAL)
Secondary Consumer: mouse (100 KCAL)
Primary Consumer: grasshopper (1,000 KCAL)
Primary Producers: grass (10,000 KCAL)
Food Chain
• The transfer of food from trophic level to
trophic level.
level
• Example of a food chain:
1.
2.
3.
4.
5.
Primary producer:
phytoplankton
Primary consumer:
zooplankton
Secondary consumer: fish
Tertiary consumer:
fisherman
Quaternary consumer: shark
Food Web
• The map of all interconnections between
food chains for an ecosystem.
Biomass
• The amount or mass of organic material in
an ecosystem.
ecosystem
Primary Productivity
• Is the rate where solar energy is converted
to the chemical energy of organic (glucose)
compounds by autotrophs (plants).
• Net primary production equals
photosynthesis - cellular respiration
Tropical Rain Forest
• Occur in equatorial areas
• High abundance of yearly rain
(>250 cm a year in some areas)
• Has the highest number of different
species per square mile.
Tropical Rain Forest
• Human impacts a great concern:
1. Clear cutting for wood and farmland.
2. May cause large scale changes in world climate.
3. There will be a large scale loss of species.
Negative Impacts to Ecosystems
1. Clear-cutting of forest upsets chemical cycling.
2. Eutrophication:
increased mineral input
which chokes aquatic life.
3. Environmental disasters: “Valdez Oil Spill”
4. Pollution:
water, air (acid rain), pesticides
and herbicides.