1. Land and Water Use and a bit of a recap
Community Ecology
Land and Water Use and a bit of a recap

2. Terrestrial Communities
Michigan contains areas of this
100 30 20 50 10 ft m
Tropical
rain forest
Coniferous
forest
Deciduous
forest
Thorn
forest
Thorn
scrub
Tall-grass
prairie
Short-grass
prairie
Desert
scrub
Terrestrial Communities

3. Community descriptors
Physical appearance: distribution (random, clumped, pattern), location, physical structures
Species diversity: richness (number of types of species), evenness( abundance of individuals. Remember Shannon index? Affected by:
Latitude
pollution
Niche structure: number of niches, overlap, interactions.

4. Latitude Effects on Richness
1,000
200
Species Diversity
Species Diversity
100
100 10
90ºN 60 30
30ºS 60
80ºN 60 40 20
Latitude
Latitude
(a) Ants
(b) Breeding birds

5. Pollution Effects on Richness, Evenness
Unpolluted
stream
Number of diatom species
Polluted
stream
Number of individuals per diatom species

6. MacArthur and Wilson
Study done comparing small and large island biodiversity.
Conclusions:
Small islands have less animals coming to it because it is a small target to immigrate to.
Smaller islands have higher extinction rates because of fewer resources and habitats
Islands closer to mainlands will have higher immigration of animals.

7. Species
Native: species that normally live in an area. In Iowa: whitetail deer, squirrel, bass, etc.
Non-native: AKA invasive or alien. Brought into an area intentionally or accidentally. Can often overtake native species. Asian beetle, water milfoil, zebra mussel, etc.
Indicator: species that will be affected first by environmental change. Trout (temperature), frogs, birds.
Keystone: species that have an effect on a large number of other species. (pollination, predation, etc)

8. Why we love Kermit the Frog
Amphibians are excellent indicator species.
Why?
Lifecycle puts it in contact with land and water
Vulnerable to a wide variety of chemicals, radiation, pollutants
Frog species loss
Habitat loss
Pollution
Hunting (frog legs)
UV radiation

9. Resource Partitioning
© 2004 Brooks/Cole – Thomson Learning
Resource Partitioning
Hawks and Owls = same prey.
Number of individuals
Species 1
Species 2
Region of
niche overlap
Resource use
Hawks – hunt by day Owls – hunt by night
Number of individuals
Species 1
Species 2
Resource use

10. Resource Partitioning

11. Prey Defense Mechanisms
Avoidance: Hedgehogs (rollup/spines), lizards tails that break off, turtle (shell),
Camouflage: coloring, patterns, etc to help blend in. Deer, frogs, etc.
Poison: Oleander plants, some frogs
Foul smell/taste: Monarchs, skunks, etc.
Warning color: bright color to show poisonous nature.
Mimicry: Look like a poisonous animal, act like another (bull snake “rattling”)

12. Prey Defense Mechanisms
Camouflage
Camouflage
Foul smell
Foul taste
Span worm
Wandering leaf insect
Bombardier beetle
monarch butterfly
Mimicry
Mimicry
Mimicry
Poison/Warning Color
Poison dart frog
Viceroy butterfly
snake caterpillar
io moth
Prey Defense Mechanisms

13. Relationships Predator-Prey: “eat or be eaten”
Parasitism: one organism lives off of another. Host is often weakened, but not killed. Examples: tapeworms, wood ticks, cowbird eggs.
Mutualism: both species in relationship will benefit. Example: clown fish/sea anemone.
Commensalism: one organism benefits, the other is not affected. Some doubt this exists as “some effect” must occur. Example: seeds traveling on animals
Review clip for visual

14. Changes in Ecosystems: Ecological Succession

15. Definition:
Natural, gradual changes in the types of species that live in an area; can be primary or secondary
The gradual replacement of one plant community by another through natural processes over time

16. Primary Succession Begins in a place without any soil
Sides of volcanoes
Landslides
Flooding
Starts with the arrival of living things such as lichens that do not need soil to survive
Called PIONEER SPECIES

18. Primary Succession
Soil starts to form as lichens and the forces of weather and erosion help break down rocks into smaller pieces
When lichens die, they decompose, adding small amounts of organic matter to the rock to make soil

20. Primary Succession
Simple plants like mosses and ferns can grow in the new soil

21. Primary Succession The simple plants die, adding more organic material
The soil layer thickens, and grasses, wildflowers, and other plants begin to take over

22. Primary Succession
These plants die, and they add more nutrients to the soil
Shrubs and trees can survive now

23. Primary Succession
Insects, small birds, and mammals have begun to move in
What was once bare rock now supports a variety of life

24. Secondary Succession
Begins in a place that already has soil and was once the home of living organisms
Occurs faster and has different pioneer species than primary succession
Example: after forest fires

28. Climax Community
A stable group of plants and animals that is the end result of the succession process
Does not always mean big trees
Grasses in prairies
Cacti in deserts

30. Primary Succession
Starts with: barren rock (land) or rock bottom of lake, river, stream. Examples: area after volcanic eruption, glacier retreat.
Pioneer species: usually lichen and moss. Begins to break down rock to make soil.
Early successional plants: annuals, low growing, short lives.
Midsuccessional plants: herbs, taller grasses, shrubs.
Late successional plants: mostly trees.
Climax community (succession completed)
View clip

31. Primary Succession Review soil formation Balsam fir, paper birch, and
Exposed
rocks
Lichens
and mosses
Balsam fir,
paper birch, and
white spruce
climax community
Jack pine,
black spruce,
and aspen
Heath mat
Small herbs
and shrubs
Time
Review soil formation

32. Secondary Succession
Starts with: disaster or human activity that destroys environment, but soil remains.
Follows same process as Primary succession, but lengthy soil making process gets to be “skipped”
First to re-grow: small grasses, plants then leads to larger shrubs and trees.

33. Mature oak-hickory forest
Young pine forest
Perennial
weeds and
grasses
Shrubs
Annual
weeds
Time
Secondary succession

34. Aquatic Succession Starts with: newly formed pond/lake
Typically from glacial retreat
Bottom is rocky.
Sediment is brought in by runoff, erosion.
Plants able to grow on edges only.
Plant growth, death, decay leads to more nutrients.
Normal eutrophication can lead to wetland, then meadow.
Succession would end with grassland or meadow

35. Aquatic Succession