1. Review- What effects do organisms do pioneer species have on an environment undergoing primary succession
Explain- why do communities change over time
Apply Concepts- When a whale or other large marine mammal dies and falls to the ocean floor, different waves of decomposers and scavengers feed off the carcass until nothing remains- do you think this is an example of succession- explain

2. Ch 4 Ecosystems and Communities
4.3 Succession

3. Krakatau exploded in 1883, leaving a tiny, barren island.
2 years later grasses were growing
14 years later there were 49 plant species, along with lizards, birds, bats, and insects
1929, a forest containing 300 plant species had grown
How did the island ecosystem recover so quickly.

4. Ecological Succession
Series of more-or-less predictable changes that occur in a community over time
Some species move in and some die out
Number of species typically increase.

5. Primary Succession
Succession that begins with bare rock.

6. Primary Succession Pioneer Species
First species to colonize barren areas
Lichen—mutualistic symbiosis between a fungus and an alga- often the first life
Fix atmospheric nitrogen, break down rock, and add organic material to form soil.

7. Secondary Succession
Succession that begins with some surviving species and soil
Occurs faster than primary succession
Often follows natural or human disturbance.

8. Climax Communities
Species in a stable, mature environment that won’t change into a different community.

9. Natural Disturbances
Secondary succession in healthy ecosystems after natural disturbances often reproduces the original climax community.

10. Human-Caused Disturbances
Ecosystems may or may not recover from extensive human disturbances.

11. Succession Lab
Place a handful of dried plant material into a clean jar
Fill the jar with boiled pond water and determine the initial pH of the water
Cover the jar and place it in an area that receives indirect light
Examine the jar every day for the next few days
When the water in the jar appears cloudy, prepare microscope slides of water from various levels of the jar using a pipette to collect the water
Look at the slides under the low powered objective lens and record your observations

12. Succession Analyze and Conclude
Infer- Why did you use boiled water
Infer- Where did the organisms you saw come from
Draw Conclusions- Was ecological succession occurring- give evidence to support your answer
Evaluate and Revise- Check you results against those of you classmates- Do they agree, how do you explain the differences