1. Chapter 3 Communities and Biomes Part 1

2. Ecosystem: interactions among populations in a community
Consists of:
A community of organisms
The soil, water, and weather
Energy

3. Succession: changes over time
Primary succession – gradual growth of an ecosystem over a long period of time. Example: Hawaii. Rock -> Lichen -> moss -> grass -> shrub -> tree -> vines

4. Succession: changes over time
Pioneer species – first species in an area

6. Succession: changes over time
Climax community – shows little or no change over time
Secondary succession (previously supported vegetation) – sequence of life after natural disasters (examples: Forest fires, glaciers, avalanches, flood, hurricane, tsunami, tornadoes).
1988 forest fire in
Yellowstone Nat’l Park

7. Chapters 3-4 Communities and Biomes / Population Part 2

8. Biome - a major ecosystem that shares the same type of climate and has similar life forms.
Salt water
Freshwater
Estuary (mix of salt and fresh water)
Terrestrial (dry land)

9. CLIMATOGRAM - Measures two things:
Average Temperature
Average Precipitation

10. Tundra (Alpine and Arctic)
Permafrost - permanently frozen ground
Plants - short roots; fast growing; perennials.
Animals have thick fur / body fat / coloration.

11. Taiga / Coniferous Forest
Conifers - cone-bearing trees / bending branches / needles as leaves. Animals also have thick fur / body fat.

12. Temperate / Deciduous Forest
Broad - leaved trees lose their leaves yearly. Some birds migrate.

13. Tropical Rain Forest Arboreal - tree-dwelling animals Trees / Plants:
1. Canopy Understory Ground

14. Desert Most desert animals are nocturnal.
Estivation - sleeping during hot days.
Plants have waxy leaves / spines.

15. Grasslands (Savanna and Temperate) What are Steppes?
Most animals have good vision and speed.
Plants have underground stems / survive fires.

16. Aquatic Biomes Freshwater – Ponds, lakes, streams, rivers, wetlands.
Marine – Oceans, coral reefs, estuaries.

18. Population Dynamics
Exponential Growth - as a population gets larger, it also grows faster.
Carrying capacity - the maximum number of organisms that an environment can support.

19. Limiting factors: Factors that affect an organism’s ability to survive.
Density dependent factors:
Disease
Competition
Parasites
Food & water
Space

20. Density independent factors (abiotic factors):
Temperature
Storms
Floods
Drought
Habitat disruption (logging, burning, draining swamps, moving in exotic species)

21. Demography - human population growth
Immigration - moving in
Emigration - moving out
Natality - birth rate
Fatality - death rate
Growth rate

22. The End!