1. Ecological Succession

2. What is ecological succession?
It is a process in which communities of organisms replace one another over time in an ecosystem.
A lake area may become a marsh followed by grassland/meadow and then a forest.

3. What are intermediate communities?
Animals and plants that may be a mixture of the community that has been there and the one that is coming in.

4. What is a climax community?
A relatively stable community.
It is determined by climate.
Communities in our area:
Rochester – oak savanna
Austin – Grassland
LaCrosse – Deciduous forest

5. Development on bare rock, lava flows, sand dunes and lakes are examples of what?
Primary succession

6. Bare Rock succession
lichens
mosses

7. Sand dunes
grasses
shrubs
trees

8. What is a pioneer species? The first plant to inhabit and area
Lichens on a rock
Lilypads on a lake

9. Eutrophication is an example of succession
The decrease of oxygen causes a die off of many species.
The lake edges move inward as organic matter builds up on the sides and bottom of the lake.
It becomes a marsh, then meadow, then willow community and finally a forest.

10. Describe the stages of succession on a sand dune.
Wind and or waves deposit organic matter on the sand.
Grasses stabilize the sand and add their nutrients.
Shrubs replace the grasses then trees follow.

11. Where does secondary succession occur and how?
Where a community once occurred and was lost due to natural disasters or human impact.
Floods, earthquakes, hurricanes, tornados
Farming, housing……

12. Describe old field succession.
If a field is left unplanted by a farmer the following plants will grow in this order:
Crab grasses as the pioneer species followed by: dandelions, thistles, raspberries, sumac, boxelder trees, maples(50 years) , oak and walnut.
In total it will take about 200 years for a mature forest to become established.

13. Does the formation of soil ever stop?
No, but we can use it faster than it can be replaced.

14. What could interfere with the natural stages of succession?
Building
Fertilizing
Farming
Floods
Tornados
Fires
Pollution
Logging
Plant diseases, drought…….global warming…..