A. Forest: A community of trees, vegetation and animals interacting together
B. Ecology: The study of the interrelationship between living and nonliving organisms
1. Because all things in a natural system are related, disturbing the system can effect many different components
C. Ecosystem: The relationship between, soil, water, plants, climate, time, and animals
D. Succession: Natural, gradual change in an ecosystem
II. Components of the forest
A. Climate: Long-term atmospheric conditions
1. Weather: short-term conditions
2. Climatic trends: Long-term in duration (i.e., global warming)
3. Moisture: Each forest plant has a different water need
a. Rain, fog, drought, snow melt, and flooding all represent different forms of moisture conditions
a. Forest communities grow close together providing wind protection to its members
a. Light and temperature needs vary by plant
B. Soil: Thin layer of weathered mineral and organic material
1. Forest soil provides support, nutrients and water to plants
2. Soil varies depending on parent material, age, surrounding vegetation and climatic conditions
3. Soil litter: Twigs, leaves, flower, fruit, etc. in all stages of decomposition
a. Forest litter holds in moisture, provides habitat, slows run-off and erosion, and provides mineral nutrients to surrounding plants
4. Forest soil profile: O - organic litter; A - topsoil; B - subsoil; C - parent material
5. Soil texture
6. Soil fertility: Ability of soil to supply essential nutrients to plants
a. N and P are key components of fertile soil (C, H and O are all supplied in the air)
b. Other nutrients, including sulfur, calcium, potassium and magnesium come from decomposing organic material in the soil
1. Tropical Rain Forests: Equatorial zone; characterized by heavy rain and extreme biodiversity.
2. Savanna: tropical grasslands.
3. Desert: Characterized by very little rain fall; located at latitudes of 30˚ north and south.
4. Chaparral: Regions of mild, rainy winters and long, hot, dry summers; southern California, Chile, coastal Australia.
5. Grasslands: transitional areas between deserts and temperate forests; region includes plains and prairies of North America, steppes of Russia, veld of South Africa and the pampas of Argentina.
6. Temperate Deciduous Forests: Characterized by a warm, mild growing season, with moderate rainfall.
7. Coniferous Forests: Taiga - northern forests with long, severe winter; Pacific Coast forests - Alaska to Baja California, Japan, Korea and coastal Siberia
8. Tundra: Characterized by extremely cold climate, with very long winters; little plant life is supported here.