1. Communities and Biomes

2. The Role of Climate
Weather- day-to-day condition of Earth’s atmosphere at a particular time and place
Climate- The average, year-after-year conditions of temperature and precipitation in a particular region

3. The Role of Climate Climate is caused by the interplay of:
Trapping of heat by atmosphere
Latitude (location on Earth’s surface)
Transport of heat by winds and ocean currents
Amount of precipitation that results
Energy of incoming sunlight; solar energy has VERY IMPORTANT effect on the temperature of the atmosphere

4. The Greenhouse Effect
Carbon dioxide, Methane (CH4), water vapor/gas + other atmospheric gases TRAP heat energy and maintain Earth’s temperature range
Similar to the role played by glass windows inside a greenhouse!
Greenhouse Effect: The natural situation in which heat is retained by this layer of greenhouse gases

5. The Greenhouse Effect
Greenhouse gases allow sunlight (solar energy) to enter Earth’s atmosphere
Much of this energy is converted to heat energy (ENERGY PY.) and then radiated back into the atmosphere
However, same gases DO NOT allow heat energy to pass out of the atmosphere/trap energy; to modulate/control Earth’s average temperature

7. The effect of Latitude on Climate
Earth is sphere tilted on its axis; solar radiation strikes different parts of Earth’s surface at angle that varies throughout the year
At equator- Noon all year, Sun directly overhead
At Poles-Sun much lower in sky for months at a time
Therefore, more heat delivered to equator vs. poles

9. The effect of Latitude on Climate
As a result of differences in latitude and thus, the angle of heating, Earth has (3) main climate zones: polar, temperate and tropical
Polar- cold areas;sunlight strikes at low angle
Tropical-hot areas; receive direct sunlight all year
Temperate-moderate temperature; between other two zones

11. Heat Transport in Biosphere
Unequal heating of Earth’s surface drives winds and ocean currents
Results in the transport of heat throughout biosphere
Winds form-warm air rises while cool air sinks
Therefore, heated air at equator rises while cooler air at poles sinks
Upward movement of warm air/downward movement of cool air = air currents/winds that move heat throughout atmosphere; climates affected!
Similar effects occur in oceans; Ocean Currents!

13. Community
Community- Interaction of numerous populations of organisms in one defined area
Limiting factors- environmental factors that affect an organism’s ability to survive in its environment (food availability, predators, and temperature)
Limiting factors is any abiotic/biotic factor that restricts the existence, numbers, reproduction or distribution of organisms

14. Succession
Succession- the orderly, natural changes and species replacements that take place in a community
Succession occurs in stages; different species at different stages create conditions that are suitable for some organisms and unsuitable for others
This change can take decades or centuries for one type of community to succeed another

15. Succession
Primary succession- The colonization of new sites by communities of pioneer organisms
Pioneer organisms- those organisms able to “create” appropriate living conditions for other species from nonliving materials
Ex. LICHEN = THE PIONEER ORGANISM

16. Primary Succession

17. Succession
After some period of time, primary succession slows down and, after many changes in species composition, the communities become fairly stable
Climax Community- A stable, mature community that undergoes little to no change in species
Usually, pioneer organisms produce soil for autotrophs/producers to colonize and grow
Subsequently, Primary and Secondary consumers colonize the same environment, once conditions are correct for growth

18. Succession
Secondary succession- Sequence of community changes that takes place after a community is disrupted by natural disasters (flood, forest fire or hurricane) or human actions/inactions (farmer leaving field to fallow)
Difference between two forms of succession: a. secondary succession occurs in the PRESENCE of SOIL and environment PREVIOUSLY COLONIZED with living organism
b. Seconary succession occurs at a much faster rate

19. Secondary Succession