1. Unit 9: Ecology

2. Bell Ringer
Each day you rely on living organisms and the non-living environment for your survival. You do this without giving it second thought. Brainstorm 3 ways you depend on living organisms for survival and 3 ways your depend on nonliving things to live. Compare your response with the person next to you.

3. LEQ – Describe the ecological levels of organization in the biosphere.

4. I. Ecology and Interdependence
A. Ecology – study of living organisms and how they interact with each other in their environment
B. Interdependence – one change can affect all species
1. Examples:
a. Humans rely on oxygen made by plants
b. Plants rely on CO2 released by humans and volcanic eruptions

5. II. Factors Within an Ecological Environment
A. Environment made up of two factors:
1. Biotic factors - all living organisms on Earth
a. Ex. Humans, insects, bacteria
2. Abiotic factors – nonliving parts of the environment
a. Ex. Rocks, soil, water

6. Quick Review: Write response below
For the following image write down:
3 biotic factors
3 abiotic factors

7. III. Biosphere Levels of Organization
A. Organism - SMALLEST
1. Any unicellular or multicellular organism exhibiting life
B. Population
1. Group of species that can INTERBREED and produce FERTILE offspring
C. Community
1. Several interacting populations and are interdependent
D. Ecosystem
1. Many populations (biotic) within a community and abiotic factors they interact with
E. Biome
1. Regions of the world with similar climate, plants, and animals
F. Biosphere - LARGEST
1. Life supporting portions of Earth with air, land, fresh water, and salt water

8. Quick Review: Write response below
List the levels of organization that contain only BIOTIC factors from smallest to largest.
List the levels of organization from smallest to largest that contain BOTH abiotic and biotic factors.

9. IV. Adapting to a Changing Environment
A. Acclimation – adjusting an organisms tolerance to abiotic factors
B. Types of acclimating:
1. Conformers – change internal conditions as environment changes
a. Ex. Snakes, lizards
2. Regulators – use energy to control internal conditions despite environmental changes
a. Ex. Humans – shiver when cold, sweat when hot
b. Ex. Dogs – pant when hot

10. V. Escape from Extreme Conditions
A. Organisms must adapt to conditions or they will die
B. If they cannot adapt, they must move until conditions are better
1. Migration – moving to a new area
a. Ex. Birds
C. Dormancy – Two types
1. Estivation – dormancy during extreme hot/dry weather
a. Ex. Frogs, salamanders, crocodile
2. Hibernation – dormancy during cold weather
a. Ex. Bear, squirrel

11. Quick Review: Write response below
For the image to the right drawn an arrow to regulators and circle the conformers.
Contrast estivation and hibernation.

12. VI. Types Terrestrial Ecosystems
A. Terrestrial Ecosystems – found only on land
1.Biomes
B. Biotic factors:
1. Animals
2. Plants
3. Vegetation
4. Insects
5. Trees
C. Abiotic factors:
1. Sunlight
2. Pollution
3. Temperature
4. Precipitation

13. VII. Types of Aquatic Ecosystems
A. Aquatic Ecosystems – found only in a body of water
1. Ocean Zones
a. Photic zone – light penetrates
b. Aphotic Zone – deep; light doesn’t penetrate
c. Oceanic – made up of photic and aphotic
d. Neritic – productive; coral reefs and plankton
e. Intertidal – high and low tide 2x’s daily
2. Estuaries – river meets sea
a. Ex. Chesapeake Bay
3. Lakes/Ponds
4. Rivers/Streams
5. Freshwater Wetland
a. Ex. Marsh and swamps
B. Biotic Factors:
1. Fish
2. Coral Reefs
3. Phytoplankton
C. Abiotic Factors:
1. Sunlight
2. Oxygen – at water surface
3. Pollution
4. Temperature

14. Quick Review
Create Venn diagram. Place terrestrial ecosystems on the left, aquatic ecosystem on the right, and similarities in the middle. Write at least 3 factors for each group.

15. Bell Ringer
Take 2 foods that you ate yesterday and SEPARATELY list each item’s energy source, then that item’s energy source. Go back as far as you possibly can. Do you notice any similarities between both food types as to where you ended up?

16. LEQ – Describe interactions and relationships in an ecosystem.

17. I. Types of Organisms Name Energy Source Examples
Producer/Autotroph Makes own food Grass, ferns, tree
Consumer/Heterotroph Eating other Humans, organisms mice, ants
Herbivore Eat only producers Cows, deer sheep
Carnivore Eat only consumers Lions, hawks
Omnivore Eat producers and Humans, pigs, consumers bear
Decomposer/ Break down dead Fungi,
Detritivore organisms and return bacteria nutrients to soil/water

18. II. Organism Energy Sources
A. Autotrophs/Producers – make own sugar from light, water, and CO2
1. Photosynthesis – Energy source is sunlight
a. Chemical Equation: 6CO2 + 6H2O + light energy  C6H12O6 + 6O2
2. Chemosynthesis – used by chemosynthetic bacteria in absence of light; Energy source is hydrogen sulfide
3. Ex. Plants, trees, chemosynthetic bacteria
B. **Autrotrophs are primary producers within an ecosystem**
C. Heterotrophs/Consumers– get energy by eating other organisms
1. Cellular Respiration – breaking down glucose to release water, ATP, and CO2
a. Chemical Equation: C6H12O6 + 6O2  6CO2 + 6H2O + energy (ATP)
2. Ex. Humans, dogs, spiders

19. III. Energy Transfer
A. Energy is transferred through an ecosystem from producers to consumers.
B. Three models to show this transfer of energy:
1. Food Chains
2. Food Webs
3. Energy Pyramids
C. Remember – only 10% of energy moves from one level to the next
1. Why is it important to have a good amount of producers to sustain an ecosystem?

20. III. Energy Transfer Continued
A. Food Chains – energy transferred as 1 organism eats another
1. Only 10% of Energy goes to next level
2. Shows hierarchy of species
3. One path
B. Food Web – shows what organisms eat in ecosystem
1. Shows feeding relationships
2. MANY paths
C. Energy Pyramid – shows amounts of energy, biomass, or numbers of organisms at each trophic level

21. Quick Review: Write response below
If there’s 250J of energy at the bottom of an energy pyramid, how much energy is in the next level? __________ Then the following? _________
Contrast food chains and food webs.

22. IV. Biotic Interactions in an Ecosystem
A. Organisms interact daily with one another in order to survive
B. Types of interactions include:
1. Symbiosis – interaction of organisms in CLOSE proximity
a. Commensalism(+/0) – one benefits, one is neutral (neither harmed nor benefited)
1. Ex. Remora fish and shark
b. Mutualism (+/+) – both organism benefit
1. Ex. Crocodiles and birds
c. Parasitism(+/-) – one benefits and one is harmed
1. Ex. Tapeworm and human
2. Predation – one organism (predator) eat another (prey)
1. Ex. Lion and gazelle
3. Competition – happens when more than one organism uses a resource (food, water, space, light) at the same time
1. Strong compete with weak organism  strong organisms survive

23. Quick Review: Write response below
Why are predation and competition not considered symbiotic? (Hint- think of some examples of these interactions and how the LOCATION compares to that of symbiotic interactions.)

24. V. Biogeochemical Cycling
A. Biogeochemical Cycle – exchange of matter through the biosphere
1. Essential nutrients are cycled through an ecosystem through biogeochemical cycles
2. Movement of nutrients through biotic and abiotic elements in an ecosystem are critical to life on Earth
B. Types of Cycles:
1. Water Cycle
2. Carbon Cycle
3. Oxygen Cycle
4. Nitrogen Cycle

25. 1. Water Cycle
A. Water is found  underground, in atmosphere, lakes, streams, rivers, glaciers, ice caps, oceans
1. Evaporation - water from Earth moves into atmosphere
2. Transpiration - water taken in by plants through roots and released into atmosphere
3. Condensation - water in atmosphere condenses into clouds
4. Precipitation -rain released from clouds to the ground

26. 2. Carbon Cycle
A. Carbon take out of atmosphere via photosynthesis and plants create glucose
B. Animals eat plants and use nutrients to make carbs, fats, proteins
C. Organisms release organics carbon compounds through wastes and into atmosphere via respiration
1. CO2 also release from geochemical activities like volcanoes
D. Remaining organic carbon remains in organism until death  decay  release CO2 back into air
E. Human Activity  Fossil Fuels (Coal, oil, gas)
1. Burning release Carbon Dioxide into atmosphere  Greenhouse Effect

27. 2. Carbon Cycle

28. 3. Oxygen Cycle oxygen photosynthesis respiration carbon dioxide
A. Plant photosynthesis  Release oxygen
B. Animals inhale oxygen  release carbon dioxide (respiration)
C. Plants take up Carbon dioxide  photosynthesis… Cycle continues
oxygen
respiration
carbon
dioxide
photosynthesis

29. 4. Nitrogen Cycle
A. Nitrogen – essential element of amino acids and nucleic acids (DNA and RNA)
B. 80% of Earth’s atmosphere is nitrogen gas (N2)
1. Producers can only use the form of ammonium (NH4) and nitrates (NO3)
C. How do we convert it?
1. Nitrogen-fixation – nitrogen fixing bacteria in sold and plant root nodules convert nitrogen gas to ammonia (NH3)
2. Ammonia in soil picks up hydrogen from water and forms ammonium (NH4)
3. Nitrification – soil bacteria convert ammonium to nitrates

30. 4. Nitrogen Cycle Continued
D. What do producers do with it?
1. Producers absorb ammonium and nitrates  BUILD AMINO ACIDS, PROTEINS, and NUCLEIC ACIDS
E. Animals eat plants and make proteins from them
1. Give off wastes and eventually die
F. Decomposers – convert nitrogen in wastes and dead matter into ammonium
G. Denitrifying bacteria (in soil) convert nitrates back to nitrogen gas  goes into atmosphere
H. Lightning  CONVERTS NITROGEN GAS INTO NITRATES

31. 4. Nitrogen Cycle Continued

32. Quick Review: Write response below
What is the importance of biogeochemical cycle to survival on Earth? Why would happen if these nutrients did not cycle?
What role do N-fixing and denitrifying bacteria play in the N-Cycle?
N-Fixing:
Denitrifying:

33. VI. Population Dynamics
A. Population – Group of organisms that belong to same species and live in same particular area
B. Factors that Influence Growth:
1. Birth rate - # of births
2. Death rate - # of deaths
3. Emigration – individuals Exiting area
4. Immigration – individuals coming Into area

34. VII. Population Fluctuations
A. High and low population numbers can be linked to:
1. Environmental changes
a. Temperature change
b. Habitat loss
c. Weather conditions
2. Predator/Prey relationships
a. Ex. Hare/Lynx

35. VIII. Population Limiting Factors and Models
A. Limiting factors – restrict population growth
1. Ex. Water, food, space, mate availability
B. Exponential Model (J-Curve)
1. Increase in # (birth rate > death rate)
2. Doesn’t account for limiting factors
C. Logistic Model (S-Curve)
1. Population grows, then levels off when LIMITING FACTORS kick in
2. Carrying Capacity (K) - # of individuals environment can support

36. IX. Limiting Factor Influences on Carrying Capacity
A. Carrying capacity dependent on limiting factors
B. Two types:
1. Density-independent factors
a. Reduce population no matter # present
b. Examples: Weather, floods, fires
2. Density-dependent factors
a. Triggered by increasing population density
b. Examples: Food supply, water supply, habitat, predation, competition

37. Quick Review: Write response below
Which type of population models shows rapid growth until limiting factors kick in and then levels off?
Give an example of a density-independent limiting factor.
Give an example of a density-dependent limiting factor.
What do these limiting factors do to the carrying capacity?

38. X. Biodiversity A. Biodiversity
1. Variety of species in an area
2. Increases ecosystem stability  less influenced by change in an ecosystem
B. Consequence of decreased biodiversity
1. Inbreeding – causes less genetic variability  CAN’T ADAPT WELL
2. Threatened species – on verge of becoming endangered
3. Endangered species – on verge of becoming extinct
4. Extinct – species no longer exists

39. XI. Decrease Biodiversity from Natural and Human Disturbances
A. Natural Disturbances – happen on occasion
1. Major adverse event due to Earth’s natural processes
2. Ex. Floods, volcanic eruptions, wildfires
B. Human Disturbances – put constant pressure on ecosystems
1. Human overpopulation – exceeding carrying capacity  deplete sources quicker like fossil fuels
2. Climate change – average temp. of biosphere increases
a. Organisms need to move to places they never live; some will go extinct
3. Nonnative species – intentionally or unintentionally put in new habitat
a. Increase in number – no natural predators  OUTCOMPETE NATIVES
b. Ex. Kudzu and zebra mussels

40. XI. Decreased Biodiversity – Human Disturbances Continued
4. Pollution – change air, soil, water composition
a. Biomagnification – toxin concentration increases up through trophic levels
1. Ex. DDT, mercury
b. Acid Rain – caused from fossil fuels and auto emissions
1. Removes nutrients from soil  deprives plants of nutrients
2. Accumulates in rivers, lakes, streams
c. Eutrophication – fertilizers, sewage, and nitrogen wastes accumulate in waterways  Algal blooms
1. Algae suck up al oxygen in water  organisms suffocate

41. XI. Decreased Biodiversity – Human Disturbances Continued
5. Overexploitation - Excessive use of species that have an economic value
a. Can lead to their extinction
b. Example – American bison were hunted to the brink of extinction.
6. Habitat loss - Habitat destroyed or disrupted  native species must relocate or they could die
a. Example – clearing areas of tropical rainforests displaces native species
7. Habitat fragmentation - Separation of an ecosystem into small pieces of land
a. Smaller areas of land support fewer species and introduce barriers for individuals in a species to reproduce
b. Genetic diversity may occur in the separated populations
c. Example – Constructing roads through a forest divides the forest into smaller areas

42. XII. Implications of Human and Natural Disturbances
A. All these disturbances cause:
1. Loss of biodiversity
2. Loss of stability
3. Loss of habitat
4. Increased extinction rates
5. Disruption of natural biological cycles

43. Quick Review: Write response below
Write down 2 examples of human and natural disturbances.
How do these disturbances influence biodiversity?

44. XIII. Ecological Succession
A. Although an ecosystem can be wiped out due to natural or human disturbances, it can regrow OVERTIME through succession
B. Succession – pattern of change overtime
1. Due to  species being more/less adapted to new environment or disasters
C. Types of succession:
1. Primary Succession
2. Secondary Succession

45. 1. Primary Succession
A. Primary Succession - Succession that occurs on surfaces where no ecosystem existed before (no soil present)
1. Slower than secondary succession
2. Need to start with creating soil from bare exposed rock  eventually lead to mosses, grasses, etc.

46. 2. Secondary Succession
A. Secondary Succession - Succession on surface where an ecosystem previously existed (soil was/is already present)
B. Causes:
1. Volcano eruption
2. Storm
3. Fires
4. Abandoned farmland, logging, mining

47. Quick Review: Write response below
Write down two key differences between primary and secondary succession.