1. The Biosphere - Matter and Energy, Interdependence in Nature
Chapter 3

2. Studying our Living Planet
Life on a global scale – biosphere
Includes land, water, atmosphere and LIVING THINGS
Extends 8 km above the land surface and 11 km below the ocean surface
Ecology – study of the interactions between organisms and their surroundings

3. Studying Our Living Planet
Levels of organization
Species
Population
Community
Ecosystem
Biome
biosphere

4. Biotic and Abiotic Factors
Biotic – any part of the living environment
Animals
Plants
Mushrooms
bacteria
Abiotic – any nonliving part of the environment
Sunlight
Heat
Precipitation
Humidity
Wind
Water currents
Soil types

5. Ecological Methods Three methods Observation Experimentation Modeling
Use of senses
Can be simple or complex
Experimentation
Can be set-up in a lab or out in a select-part of natural environment
Modeling

6. Energy, Producers & Consumers
Energy = life function
Ultimate energy source = the sun
Some organisms use chemical energy from inorganic sources
Autotrophs – organisms that use solar or chemical energy to produce “food”
AKA – primary producers

7. Primary Producers Solar energy converted through photosynthesis
Converts CO2 &H2O into O2 and carbohydrates
Plants (on land) and algae (in the water)
Chemical energy converted where light is not available or conditions are harsh - chemosynthesis

8. Consumers Heterotrophs – get their energy from consumption
AKA – consumers
Types of consumer – based on what they eat

9. Energy Flow in Ecosystems
Food Chains and Food Webs
Everyone is linked through feeding relationships
Energy flow  one way stream from producers to consumers
Food Chain – series of steps that move energy from eating to eaten
All food chains start with a producer
Terrestrial – plants
Aquatic – either plants OR phytoplankton

10. Examples of Food Chains

11. Energy Flow in Ecosystems
Most feeding relationships are more complicated than a simple series
Most organisms have a multi-food diet
Food Web
Network of feeding interactions
Also starts with a producer (SAME AS FOOD CHAINS)
Links multiple food chains
Effects of disturbances?

12. Example of Food Web

13. Trophic Levels and Ecological Pyramids
Trophic level – each step in a food chain or food web
Biomass – total amount of living tissue in a given trophic level

14. Trophic Levels and Ecological Pyramids
Ecological pyramid – show relative amount of matter or energy within a given food chain or web
The rule of 10 – in general, only 10 percent of the energy available in one level is stored in the level above
Organisms use most of the energy they get on life processes … the rest is release as heat
Higher up the pyramid – organisms require more food to get the energy they need … so there are less of them!