1. ECOLOGY

2. What is ecology?
Ecology- the scientific study of interactions between organisms and their environments, focusing on energy transfer Ecology is a science of relationships

3. WHAT DO YOU MEAN BY ENVIRONMENT?
The environment is made up of two factors:
Biotic factors-
all living organisms inhabiting the Earth
Abiotic factors-
nonliving parts of the environment (i.e. temperature, soil, light, moisture, air currents)

4. Biosphere Biome Ecosystem Community Population Organism
Ecological hierarchy
Biosphere Biome Ecosystem Community Population Organism

5. Biosphere Biome The highest level of organization
Life supporting portions of Earth composed of air, land, fresh water, and salt water.
Biome
A specific geographic area notable for the species living there (flora and fauna)

6. Ecosystem
populations in a community and the abiotic factors with which they interact (ex. marine, terrestrial)
Community
several interacting populations that inhabit a common environment and are interdependent
Population
a group of organisms of one species living in the same place at the same time that interbreed and produce fertile offspring
Compete with each other for resources (food, mates, shelter, etc.)

7. Organism
any unicellular or multicellular form exhibiting all of the characteristics of life, an individual.
The lowest level of organization

8. Location vs occupation
Habitat
the place in which an organism lives out its life
Niche
the role a species plays in a community; its total way of life
Although several species may share a habitat they each have their own niche

9. Limitations
A niche is determined by the tolerance limitations of an organism, or a limiting factor.
Limiting factor
any biotic or abiotic factor that restricts the existence of organisms in a specific environment.
Examples of limiting factors
Amount of water
Amount of food
Temperature
Amount of space
Availability of mates

10. Energy transfer Energy is transferred in two ways:
Directly from the sun
Feeding
There are three feeding relationships that organisms can be a part of
1. Producer -> Consumer
2. Prey -> Predator
3. Host -> Parasite
Arrows are used to show the flow of energy between organisms

11. Feeding Relationships
Producer
autotrophs (plants)
trap energy from the sun
Bottom of the food chain
Consumer
heterotrophs: they ingest food
Four types
Herbivores
Carnivores
Omnivores
Decomposers

12. Types of Consumers Herbivores Carnivores Omnivores Decomposers
eat plants only, primary consumers
Carnivores
eat meat
Predators - hunt prey animals for food
Scavengers -Feed on carrion,(dead animals)
Omnivores
eat both plants and meat
Decomposers
breakdown the complex compounds of dead and decaying plants and animals into simpler molecules that can be absorbed

14. Symbiotic relationships
Symbiosis- two species living together
3 Types of symbiosis:
Commensalism
one species benefits and the other is neither harmed nor helped
Ex: Orchids and trees
2. Parasitism
one species benefits (parasite) and the other is harmed (host)
Ex: leeches, fleas, ticks, tapeworms
3. Mutualism
beneficial to both species
Cleaning birds and rhinos

15. Trophic levels-food webs/pyramids
Each link in a food chain is known as a trophic level.
Trophic levels represent a feeding step in the transfer of energy and matter in an ecosystem.
Biomass- the amount of organic matter comprising a group of organisms in a habitat.
As you move up a food chain, both available energy and biomass decrease.
Energy is transferred upwards but is diminished with each transfer.
10% percent rule

16. Trophic levels Food chain Food web
simple model that shows how matter and energy move through an ecosystem
Food web
shows all possible feeding relationships in a community at each trophic level
Represents a network of interconnected food chains

17. Food chain Food web
(just 1 path of energy) (all possible energy paths)

18. E N R G Y Trophic Levels Producers- Autotrophs
Tertiary consumers- top carnivores
Secondary consumers-small carnivores
Primary consumers- Herbivores
Producers- Autotrophs

20. Toxins in food chains
While energy decreases as it moves up the food chain, toxins increase in potency.
This is called biological magnification
DDT and bald eagles

21. Nutrient cycles
Cycling maintains homeostasis (balance) in the environment.
Cycles to investigate:
1. Water (hydrologic) cycle
2. Carbon cycle
3. Oxygen cycle
4. Nitrogen cycle

22. Hydrologic Cycle Evaporation- water source to atmosphere
Transpiration- plant source to atmosphere
condensation –formation of clouds
Precipitation- atmosphere to surface
Percolation- permeates into ground water

24. Carbon and Oxygen
Photosynthesis and respiration cycle carbon and oxygen through the environment.
A carbon footprint is defined as: The total amount of greenhouse gases produced to directly and indirectly support human activities
Examples: driving a car, electronics, factory emissions
The greenhouse effect is in direct connection with the carbon cycle

25. Carbon cycle-

26. Nitrogen cycle Nitrogen fixation
Atmospheric nitrogen (N2) makes up nearly 78%-80% of air.
Organisms can not use it in that form.
Lightning and bacteria convert nitrogen into usable form. Only certain bacteria and industrial technologies can fix nitrogen.
Nitrogen fixation
convert atmospheric nitrogen (N2) into ammonium (NH4+) which can be used to make organic compounds like amino acids.
These bacteria are a part of a symbiotic relationship with autotrophs