1. Notes: Biology I S409 – Ecology Unit
Chapter 2 – Principles of Ecology
2.1 – Organisms & Their Relationships
2.2 – Flow of Energy in an Ecosystem
2.3 – Cycling of Matter
Chapter 5 – Biodiversity & Conservation
5.3 – Conserving Biodiversity

2. 2.1: Organisms & Their Relationships
definition: the scientific discipline in which the relationships among living organisms and the interaction the organism have with their environments are studied.
The study of organisms interacting with each other & the environment

3. T: 2, 9
The Biosphere
Biosphere: the portion of the Earth that supports life (polar, desert, ocean & rainforest)
Biotic Factors: factors in an organisms environment
The biological influences on organisms within an ecosystem
Examples: animals, plants, mushrooms & bacteria
Abiotic Factors: factors in an organism’s environment
Physical, or nonliving, factors that shape ecosystems
Examples: temperature, air/water current, sunlight, precipitation, humidity, soil nutrients

4. Understanding Communities
Keys to understanding biological communities is to be aware of latitude and climatic conditions
- the average conditions in a region
Temperature - # of hours/intensity of sunlight
Precipitation - amount of moisture
Topography – shape & elevation of landmasses (mountain affect)
– the condition of the atmosphere at a specific place and time

5. Levels of Organization
Ecologists that occur between the levels of organization…
Organism: one individual living thing
Species: organism that produces offspring
Population: several of same species in one place
Community: populations interacting; different species
Ecosystem: communities interacting w/ environment
Biome: large geographic area; different ecosystems w/ similar climate and communities
Biosphere: combines all parts of the planet: land, water, & air that support life
The portion of the planet that supports life

6. Levels of Organization

7. Ecosystem Interactions
Habitat: an area where an organism lives
Niche: role or position that an organism has in its environment
Community Interactions
Competition: organisms of the same or different species attempt to use the same ecological resource in the same place at the same time.
Predation: interaction in which one organism captures (predator) and feeds on another organism (prey)

8. Symbiotic Relationships
Symbiosis: a close relationship between 2 species
Mutualism: both species benefit from the relationship; Ex: bees & flowers
Commensalism: one member of the association benefits and the other is neither helped nor harmed; Ex: shark & remora fish
Parasitism: one organism lives on or inside another organism and harms it. The parasite obtains all or part of its nutritional needs from the other organism, called the host. Ex: hookworm, tick

9. 2.2: Flow of Energy in an Ecosystem
All living things require energy… where does it come from?
Originally = the sun
Stored form = chemical bonds
Organisms differ in how they obtain their energy:
troph: an organism that makes its own food
troph: an organism that gets its energy by consuming other organisms

10. Energy in an Ecosystem
T: 1, 5
Autotrophs: Capture energy from the environment to make/produce own food
AKA (Example: Green Plants)
Two ways to produce own food
Using the sun: Photosynthesis
Using inorganic chemicals: Chemosynthesis
NO sun
Ex: Hydrogen Sulfide

11. Energy in an Ecosystem Heterotrophs: rely on other organisms for food
AKA consumers; can NOT make own food
Herbivores
Eat plants only; Cow; 1st order consumer
Carnivores
Eat animals only; Snake; 2nd order consumer (or 3rd?)
Omnivores
Eat both plants & animals; Bear; 3rd order consumers
Detritivores
Engulf dead plant & animals; Worm, snail, mite
Decomposers
Absorb nutrients from dead organisms; Fungus (mushroom), bacteria

12. Concept Check
No matter how complicated a food web can get, what is the original source of energy?
What are two new names for plants?
What are two names for organisms that can NOT make their own food?

13. T: 6
Models of Energy Flow
Energy passes from source to organism to organism to organism etc.
This sequence is called a Food Chain
Sun, wheat, mouse, snake, hawk
Each link in a food chain (which is a transfer of energy) is called a Trophic Level
First trophic level is always a producer
1st, 2nd, 3rd, & 4th trophic levels are consumers
When Food Chains cross or interact it becomes a…
Food Web: a model of the relationships that form a network of interactions (producer to decomposer)

14. Models of Energy Flow…
T: 6

15. T: 6
Food Web Examples

16. Ecological Pyramids
T: 7
Ecological Pyramids: diagrams relationships (3 types)
Pyramid of Energy: each level represents the amount of energy available to that trophic level
Only 10% of energy can be passed; less energy available at each successive level or with each step up, there is an energy loss of 90%
Pyramid of Biomass: total amount of living tissue w/in a given trophic level; biomass decreases at each successive level or each level represents the amount of biomass consumed by the level above it
Pyramid of Numbers: diagrams # of individuals in each level; #’s decrease at each successive level

17. 2.3 Cycling of Matter Energy flow is matter is NOT used up!
Matter can be through ecosystems
Important Biogeochemical Cycles
Water: repeated movement of water b/w Earth’s surface & the atmosphere
Carbon & Oxygen: photosynthesis, burning of fossil fuels, decomposition of plants & animals
Nitrogen: soil nitrogen fixed by bacteria for use by organisms; atmosphere is ~80% nitrogen
Phosphorus: cycles among the land, ocean sediments, and living organisms

18. 3 Main Ways to Study Ecology
Asking questions
Making hypotheses
Usually leads to experimenting & modeling
Test hypotheses
Set up in a lab or in the field
Used when time &/or size is too large
Mathematical formulas based on above used to make predictions, which are further tested

19. Concept Check What is ecology?
What is the most simple group of more than one kind of organism in our biosphere?
What are 3 methods ecologists use to study the living world?

20. 5.3 – Conserving Biodiversity
Notes: Biology I S409 – Ecology Unit
Chapter 5 – Biodiversity & Conservation
5.3 – Conserving Biodiversity

21. 5.3 Natural Resources
The biosphere currently supplies the basic needs for more than 6 billion humans in the form of natural resources
The consumption rate of natural resources is evenly distributed
The natural resource consumption rate is much higher for people living in developed countries than for those people in developing countries
Because of the rising human population growth and an increased rate of consumption of natural resources a long-term plan for the use and conservation of natural resources is important

22. T: 12
Human Impact
Human activities - most important source for environmental change on Earth that affect the Biosphere
Hunting & Gathering: food & sport
Subsistence Hunting (hunt for food)
Agriculture: farming plants & animals
Monoculture: one type of crop in an area
Green Revolution: use of chemical fertilizers
Problems w/ pesticides (water) and resistance 
Urban Development:
Use of fossil fuel for energy
Production of waste

23. Renewable vs. Nonrenewable Resources
Renewable resources: those resources that are replaced by natural processes faster than they are consumed
can regenerate if they are alive
can be replenished by biochemical cycles if nonliving
Ex: Agriculture, Animals, Trees, Water, Solar energy
NOTE: A resource may be destroyed or polluted and will no longer be useable!! A renewable resource is not necessarily unlimited!
Nonrenewable resources: those sources that are found on Earth in limited amounts or those that are replaced by natural processes over extremely long periods of time
Ex: fossil fuels, mineral deposits, coal, oil, & natural gas and an extinct species (or cleared forests?) 

24. Use of Natural Resources
Sustainable use: using natural resources at a rate in which they can be replaced or recycled while preserving the long-term environmental health of the biosphere
Conservation of resources include:
Reducing the amount of resources that are consumed
Recycling resources that can be recycled
Preserving ecosystems
Using the ecosystem in a responsible manner
Ex: Forest Management, Aquacultures
Pollutant: a harmful material that can enter the biosphere through the land, air, or water
The contamination of air, water, or soil by materials released into the environment through human activities.

25. Comprehension Check Can you name one type of renewable resource?
Can you name one type of nonrenewable resource?
What effects do sustainable-use have on the environment?

26. Protecting Biodiversity
Protected areas in the US
1st National Park: Yellowstone National Park (1872)
Since, added many national parks and nature reserves
International protected areas
7% of the world’s land is in some type of reserve
The United Nations supports Biosphere Reserves and World Heritage Sites
This includes megareserves which have habitat areas that are protected from human activity by “buffer zones” which sustainable use of natural resources is permitted

27. Protecting Biodiversity
Biodiversity Hot Spots: An area where there are high levels of endemic species (a species only found in one specific location)
There must be at least 1500 species of vascular plants that are endemic
The region must have lost at least 70% of its original habitat
Currently 34 hot spots on the Earth.

28. Corridors between habitat fragments
Corridors: passageways between habitat fragments
Positives:
All organisms from one area to move safely to the other
Creates a larger piece of land that can sustain a wider variety of species and a wider variety of genetic variation
Negatives:
Disease can also easily pass
Increases edge effect

29. Restoring Ecosystems
T: 15
Sometimes biodiversity is destroyed in an area such that is no longer provides the abiotic and biotic factors needed for a healthy ecosystem
Cleared rainforest, mining, oil spill
Bioremediation- use of living organisms to detoxify a polluted area (microorganisms in soil to break down toxins)
Biological Augmentation- adding natural predators to a degraded ecosystem (introducing ladybugs to eat aphids; which destroy crops)

30. Legally Protecting Biodiversity
The 1970’s there was a lot of attention given to issues surrounding the environment
1973: The US enacted the Endangered Species Act
1975: International Treaty formed CITES
The Convention on International Trade in Endangered Species of Wild Fauna and Flora

31. Comprehension Check What makes something a Biodiversity Hotspot?
How many Hotspots currently exist on Earth?
What are some things that can be done to protect biodiversity?