1. Principles of Ecology
Biology

2. What is Ecology?
What is the lowest level of organization that most ecologists study?
What name is given to several organisms in the same species interacting together?
What factors are included in an ecosystem that are not included in a community?
Describe how ecosystems and biomes differ?
Which level of biological organization is the most complex?

3. What is Ecology?
What is the lowest level of organization that most ecologists study? organism
What name is given to several organisms in the same species interacting together? population
What factors are included in an ecosystem that are not included in a community? Abiotic factors
Describe how ecosystems and biomes differ? Biomes include several ecosystems over a large area.
Which level of biological organization is the most complex? Biosphere

4. Levels of Organization
Ecologist study organisms ranging from the various levels of organization:
Species
Population
Community
Ecosystem
Biome
Biosphere

5. Interrelationships
Define the 3 categories of symbiosis and give an example of each – and record in your journal/notebook
What is competition? Give an example.
What is predation? Give an example

6. Population – group of individuals of the same species
living in the same area, potentially interacting
Community – group of populations of different species
living in the same area, potentially interacting
What are some ecological interactions?

7. Why are ecological interactions important?
Interactions can affect distribution and abundance.
Interactions can influence evolution.
Think about how the following interactions can affect
distribution, abundance, and evolution.

8. Types of ecological interactions
competition
predation
parasitism
mutualism
commensalism
symbiosis

10. Competition – two species share a requirement for a
limited resource  reduces fitness of one or both species

11. Predation – one species feeds on another  enhances
fitness of predator but reduces fitness of prey
herbivory is a form of
predation

12. Parasitism – one species feeds on another  enhances
fitness of parasite but reduces fitness of host

13. Mutualism – two species provide resources or services
to each other  enhances fitness of both species

14. Commensalism – one species receives a benefit from
another species  enhances fitness of one species; no
effect on fitness of the other species

15. Symbiosis – two species live together  can include
parasitism, mutualism, and commensalism

16. Organizing ecological interactions
effect on species 1
predation
herbivory
parasitism + -
commensalism
mutualism
effect on
species 2
competition

17. Ecosystem Interactions
What is a habitat?
What is a niche?

18. Flow of Energy in an Ecosystem
What are: autotrophs, heterotrophs, herbivore, carnivore, omnivores, detritivores
What is the main energy source for life?
What is a trophic level?
How do you draw a food chain, food web? What is the difference?
What group is at the top of the pyramid of energy, biomass, numbers?

19. How does Energy flow through an Ecosystem?
Energy flows through an ecosystem in ONE direction,
sun or chemicals
Autotrophs
heterotrophs

20. Energy Flow in Ecosystems:

21. Feeding Relationships
Food Chain – steps of organisms transferring energy by eating & being eaten
Food Web – network of all the food chains in an ecosystem

22. Food Web

23. Ecological Pyramids
Trophic Level – each step in a food chain or food web
Biomass Pyramid
Energy Pyramid
Pyramid of Numbers

24. How does Matter move through an ecosystem?
Unlike the one way flow of energy, matter is recycled within & between ecosystems
Nutrients are passed between
organisms & the environment through biogeochemical cycles
Biogeochemical Cycles:
Bio –life
Geo – Earth
Chemo – chemical
WATER CYCLE
NUTRIENT CYCLES:
CARBON CYCLE
NITROGEN CYCLE
PHOSPHORUS CYCLE

25. Why are nutrients important ?
Every living organism needs nutrients to build tissues and carry out essential life functions.
95% of your body is made of…
OXYGEN
CARBON
HYDROGEN
NITROGEN

26. THE WATER CYCLE

27. Water Cycle 1 Water Water on land
enters atmosphere by evaporation, transpiration
leaves atmosphere as precipitation
Water on land
filters through ground
runs off to lakes, rivers, ocean

28. Water Cycle 2 Aquifers Runoff
underground caverns, porous layers of rock
store groundwater
Runoff
movement of surface water from land to ocean

29. CARBON CYCLE (see fig.3-13)
4 PROCESSES MOVE CARBON THROUGH ITS CYCLE:
Biological
Geochemical
Mixed biochemical
Human Activity
CO2
CO2

30. Carbon Cycle CO2 gas enters plants, algae, cyanobacteria
photosynthesis turns CO2 into organic molecules
Cellular respiration, combustion, erosion of limestone return CO2 to water, atmosphere
where it is again available to producers

31. NITROGEN CYCLE (see fig.3-14)
in Atmosphere
Nitrogen-containing nutrients in the biosphere include:
Ammonia (NH3)
Nitrate (NO3-)
Nitrite (NO2-)
ORGANISMS NEED NITROGEN TO MAKE AMINO ACIDS FOR BUILDING PROTEINS!!!
N03- &
N02-
NH3

32. Nitrogen Cycle 1 Nitrogen fixation Nitrification
conversion of nitrogen gas to ammonia
Nitrification
conversion of ammonia or ammonium to nitrate

33. Nitrogen Cycle 2 Assimilation
conversion of nitrates, ammonia, or ammonium to proteins, chlorophyll, or nitrogen-containing compounds (by plants)
conversion of plant proteins into animal proteins

34. Nitrogen Fixation

35. PHOSPHORUS CYCLE (see fig.3-15)
PHOSPHORUS FORMS PART OF IMPORTANT LIFE-SUSTAINING MOLECULES (ex. DNA & RNA)

36. Phosphorus Cycle 1 Phosphorus erodes from rock
Plants absorb inorganic phosphate from soil (through roots)
Animals obtain phosphorus from their diets

37. Phosphorus Cycle 2
Decomposers release inorganic phosphate into environment
Phosphorus washes into ocean
is deposited in seabeds
lost from biological cycles for millions of years