1. Environmental Science
Chapter 3
Notes #3

2. Energy Flow in Ecosystems
Producer /Consumer
Almost all organisms get their energy from the sun
Herbivore/ Carnivore/ Omnivores/ Decomposers
photosynthesis
6CO2 + 6H2O + light energy  C6H12O O2
Cellular respiration
C6H12O6 + 6O2  6CO2 + 6H2O + energy
Food Chain
Food Web
Energy Pyramid
Trophic Levels

3. The Cycling of Materials
There are 3 main cycles that allow for the reuse of materials
The Water Cycle
The Carbon Cycle
The Nitrogen Cycle

4. How Ecosystems Change
Ecological Succession – a regular pattern of changes over time in the types of species in a community
(Can take 1000’s of years)
Cause of succession?
Ex. Pine trees create shade – however – can’t grow in the shade – but oak and maple can, so they grow and replace the pine trees

5. How Ecosystems Change
Climax Community – the community that eventually forms if left undisturbed
ex. Maple forest remains a maple forest if no serious disturbances occur
Pioneers grow in (the 1st organisms to colonize in newly available area and start the process of succession.

6. How Ecosystems Change
Secondary Succession – when a new ecosystem occurs where there had been another
Ex. After Mt. St. Helens erupted, it left nothing, now there is regeneration
Ex. Old Field succession – when farmland is abandoned

7. How Ecosystems Change

8. How Ecosystems Change Fire maintained communities –
Natural fires are left to burn…why?
Clears out old dead brush
Allows for new plants to grow

9. How Ecosystems Change Primary Succession
Succession that occurs on surfaces where no ecosystem existed before
Ex. An island created by a volcano
Area where an exposed glacier retreats
Slower than secondary- begins where there’s no soil

10. How Ecosystems Change Ex. If glacier retreats and leaves rock behind
Lichens and bacteria move in (don’t need soil)
Fungus + alga with a mutualistic relationship
The alga photosynthesizes & the fungus absorbs nutrients from the rocks
Together they break down the rock

11. How Ecosystems Change
Water freezes and thaws in cracks, breaking it down even further
Soil accumulates as dust particles & dead remains of lichen and bacteria
Moss gains hold, dies and adds to the soil
Fertile soil is formed, seeds of small plants grow
After that it is similar to secondary succession

12. Assignments
Food Chain/Food Web/ Energy Pyramid are due Tomorrow!! Anything unfinished is homework.
Transparency Worksheets 6-8 are due today!
Transparency Worksheet 9/ Yellowstone Case Study are due tomorrow.