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 à 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