1. Succession

2. Change of Ecosystems Over Time
New Ecosystems begin when
Volcanoes form new islands
Fire burns all vegetation in an area
Glacier recedes, exposing bare rock
Farming

4. Change of Ecosystems Over Time
Pioneer Species
**Pioneer Species: first organisms to live in a new habitat
Small, fast growing plants
Make ground hospitable for others
Will be outcompeted and replaced by other plant immigrants, later on

5. Change of Ecosystems Over Time
**Primary Succession- occurs where plants have not grown before
**Secondary Succession- occurs where plants have grown before
No two successions are alike – doesn’t always lead to the same final community
Succession

6. Glacier Bay Succession Example
Glacier Bay Alaska
Glacier melts and recedes exposing bare ground
Bare ground is rocky, and nutrient poor
Pioneer seeds and spores and begin to grow close to ground
Root growing plants seeds blow in begin to grow
Eventually large hemlocks and spruces take over

7. Try This
Imagine a large forest fire destroyed all of the vegetation in an area
Starting at time zero, draw the stages representing the succession that would occur
You should have at least four stages

8. Try This

9. Whiteboards – Quick Questions
What is the difference between ecosystems and communities?

10. Whiteboards – Quick Questions
After a forest fire, what is the most likely order in which these stages appeared?
(1) D→C→A→B
(2) B→D→C→A
(3) A→B→C→D
(4) B→C→D→A

11. Whiteboards – Quick Questions
Which statement describes an activity of a decomposer?
(1) A mushroom digests and absorbs nutrients from organic matter.
(2) A sunflower uses nutrients from the soil to make proteins.
(3) A snail scrapes algae off rocks in an aquarium.
(4) A hawk eats and digests a mouse.

12. Whiteboards – Quick Questions
A relationship between a consumer and producer is best illustrated by a
(1) snake eating a bird
(2) tree absorbing minerals
(3) fungus breaking down wastes
(4) deer eating grass

13. Whiteboards – Quick Questions
Which statement represents a characteristic of an ecosystem that is not likely to sustain itself?
(1) The Sun provides the needed energy.
(2) Energy is transferred from plants to animals.
(3) There are more consumers than producers.
(4) There are interactions between biotic and abiotic factors.

14. Whiteboards – Quick Questions
Give an example of an abiotic and a biotic factor

15. Whiteboards – Quick Questions
One way humans can promote the survival of organisms in an ecosystem is to
(1) decrease diversity in plant habitats
(2) introduce new consumers to control autotrophs
(3) release extra CO2 into the atmosphere to help autotrophs
(4) learn about the interactions of populations

16. Whiteboards – Quick Questions
The diagram best represents(1) a population(2) an ecosystem
(3) a community(4) the biosphere

17. Whiteboards – Quick Questions
A bird may best be described as
(1) a decomposer that most likely feeds on nectar (a sugary liquid) from flowers
(2) a heterotroph that may eat insects and is more closely related to a robin than to an earthworm
(3) a scavenger that feeds on animals and reproduces asexually
(4) an autotroph that probes tree bark for insects and is pathogenic

18. Whiteboards – Quick Questions (Energy Flow)
Which row in the chart correctly identifies characteristics that can be associated with the members of this food chain?

19. Whiteboards – Quick Questions (Energy Flow)
Human activity caused a sharp decline in small invertebrate populations. Based on the food web, a likely consequence of this change would be
(1) an increase in the number of clams
(2) a decrease in the number of water plants
(3) an increase in the number of crabs
(4) a decrease in the number of crayfish

20. Whiteboards – Quick Questions (Energy Flow)
Which concept is best represented in the diagram below?
(1) random mutations (3) genetic engineering (2) ecological succession(4) direct harvesting

21. Whiteboards – Quick Questions (Energy Flow) - END
Which process initially provides the link between an abiotic factor and the energy needs of an entire ecosystem?
(1) respiration
(2) photosynthesis
(3) decomposition
(4) predation

22. Whiteboards – Quick Questions (Energy Flow)
Draw a food chain for the following organisms:
Snake, grass, owl, rabbit
Use your food chain to label the primary producer, primary consumer, secondary consumer, and the tertiary consumer

23. Whiteboards – Quick Questions (Energy Flow)
This diagram can be used to represent the
(1) dependency of animal survival on physical conditions in an ecosystem
(2) loss of energy from various groups of organisms in an ecosystem
(3) competition among species in an ecosystem
(4) mechanisms that maintain homeostasis in the plants in an ecosystem

24. Whiteboards – Quick Questions (Energy Flow)
Which species would most likely be a decomposer?
(1) A
(2) C
(3) B
(4) D

25. Which statement best describes the diagram?
(1) Community A is the most stable community.
(2) Community B replaced community C after a period of 100 years.
(3) Community C developed into community A after a period of 75 years.
(4) Community D modified the environment, making it more suitable for community E.

26. Whiteboards – Quick Questions (Energy Flow)
A decrease in the grass population will most immediately decrease the available energy for the
(1) mouse
(2) snake
(3) hawk
(4) frog

27. Whiteboards – Quick Questions (Energy Flow)
Which organisms are carnivores?
(1) grass and trees
(2) mouse, rabbit, and cricket
(3) deer and mountain lion
(4) frog, snake, and hawk

28. Chapter 16
Quiz Tomorrow
-Food Web Lab Due Today

29. Cycling of Materials in Ecosystems
Biogeochemical Cycles
Biogeochemical Cycles: Elements are constantly recycled and reused to maintain the health of ecosystems
Substances enter living organisms, then return to the nonliving environment

31. Cycling of Materials in Ecosystems
Biogeochemical Cycles
Three Main Cycles:
Water Cycle
Carbon Cycle
Nitrogen Cycle

32. Water Cycle

33. Carbon Cycle

34. Nitrogen Cycle