Ecology – Day #1
Ecology = study of interactions among organisms & their
surroundings
Different stages of an ecosystem (smallest to LARGEST)
1)
Species (Individuals) = group of organisms that
can breed & produce fertile offspring
2)
Population = group of organisms that belong to
the same species & live in the same area
3)
Community = group of different populations
that live together in a defined area
4)
Ecosystem = collection of all organisms that
live in a particular place, together w/ non-living
or physical environment
5)
Biome = group of ecosystems that have the
same climate & similar dominant communities
6)
Biosphere = part of earth & its atmosphere in
which living organisms exist or that is capable of
supporting life (land, water, & air)
Biology = study of LIFE
Biotic Factors = living things that shape ecosystem
- Example: Organism eating another organism
Abiotic Factors = non-living things that shape
ecosystem
Example: weather
Niche = job an organism has
Example: bee is a pollinator
Energy use in Organisms
- Main source = sunlight
Autotrophs = make own food
Example: plants
Heterotrophs = eat other organism
Example: humans
Carnivore = only eats meat
Example: Lion
Herbivore = only eats plants
Example: Zebra
Omnivore = eats plants & animals
Example: Baboon
Detritivore = eats dead organisms
Example: Crab
Decomposer = breaks down dead organism externally &
then consumes
Example: Mushroom on trees
Ecology – Day #2 (Food Webs)
Food Chain
Grass -> Grasshopper ->Frog -> Fox-> Owl
- Producer = make their own food (plants)
- Primary Consumer = eats producers
- Secondary Consumer = eats primary consumer
Trophic Levels
= Energy levels in a food chain or food web
- Each level receive ONLY 10% of the previous
trophic level’s energy
Ecology – Day #3
(Symbiotic Relationships & Carrying
Capacity)
Symbiotic Relationships
- Symbiosis = any relationship between 2
organisms that live closely together
5 Types of Relationships
1) Predation = one organism hunts & kills other
Example: Lion eats zebra
2)
Mutualism = both organisms benefit
Example: flower provides food for bee & bee
pollinates flower
3)
Commensalism = 1 organism benefits & other
organism is not effected
Example: Clown fish gets protection form
anemone but not effect anemone
4)
Parasitism = 1 organism benefits, other
organism is harmed
Example: mosquito eats human blood,
human get itchy bite
5)
Competition = 2 individuals compete for
resources (mate, shelter)
Example: 2 male deer fighting and locking
horns over a female
Carrying Capacity
= # of organisms an ecosystem can support with its
resources
- Balance between life & death
Ecology – Day #4 (Cycles)
Water Cycle = water moves between the ocean,
atmosphere (atm), & land
Carbon Cycle
- Carbon (C) is the key ingredient for ALL living
tissue
Carbon Release
- C is present as Carbon Dioxide gas (CO2) in the
atmosphere
Carbon Taken In
- Plants take in CO2 & build carbohydrates
- Organism eat carbohydrates in plants
- Decomposition = when animals die, C is released
into atmosphere
Nitrogen Cycle
- All organisms require Nitrogen (N) to make
proteins
- Nitrogen Fixation = Bacteria living in the soil fix
it so we can use it
o N2 → 2NH4
- Decomposers
o When organisms die, decomposers return N to
the soil as ammonia
- Denitrification = bacteria converts the nitrates to
N2 gas & returns to the atmosphere
o NO3  N2
Ecology – Day #5 (Succession)
Succession
= series of natural changes in the environment
2 Types
1) Primary Succession = takes place over land
with no living organisms
Example: Lava from volcano destroys everything
2) Secondary Succession = changes take place
after existing community is severely disrupted
Example: hurricane or forest fire
Pioneer Species = 1st species to occupy are undergoing
primary succession
Climax Community = stable, mature community that
undergoes little or no change in species