1. Biodiversity total number of species within an ecosystem and the resulting complexities of interactions among them Biomes all of the life-supporting regions (ecosystems) of the Earth and all of the interactions that occur among organisms and between organisms and their environment Biosphere large land areas with similar environmental conditions and characteristic plant communities

2. What Factors Influence Earth’s Climate? distribution of life is strongly influenced by weather and climate Weather : short-term fluctuations in temperature, humidity, cloud cover, wind, and rain periods of hours or days Climate : patterns of weather that prevail from year to year in a particular region A region’s climate is determined by the range of temperatures and the amount of sunlight and water

3. What Factors Influence Earth’s Climate? climate and weather are driven by the sun Solar energy drives Earth’s ocean currents, wind, and global water cycle These large-scale movements of air and water interact with the physical features of Earth’s surface to produce different climates in different places Among the factors that affect climate are air currents, ocean currents, and the presence of mountains and irregularly shaped continents

4. 90° N 90° S 90° N 90° S North Pole South Pole 0° 23.5° tilt 23.5° tilt 0° Summer in the Northern Hemisphere Summer in the Southern Hemisphere Earth’s Curvature and Tilt Produce Seasons and Climate Fig. 29-1

5. Air Currents and Climatic Regions (b) Air circulation affects climate(a) Global air circulation patterns 60° S 30° S 30° N 60° N 90° N 90° S 0° equator (tropical rain forest) 30° (desert) 30° (desert) 0° tropical rain forest taiga desert Cool air sinks, warming and drying as it descends; little rainfall occurs Warm air rises, cooling as it ascends; the water vapor in the air condenses and falls as rain The sun heats the Earth’s surface; the heat radiated from Earth warms the air

6. Ocean Circulation Patterns

7. Effects of Elevation on Temperature

8. Mountains create rain shadows Fig. 30-5 Water is carried from the ocean by the prevailing winds Water falls as rain or snow as air rises and cools Dry air sinks, warms, and absorbs water from the land dry climate in the rain shadow moist climate

9. How Is Life On Land Distributed? The distribution of terrestrial organisms is determined largely by temperature and the availability of water. Water is limited and very unevenly distributed, both in place and in time. Terrestrial organisms must be able to obtain water when it is available and to conserve water when it is scarce.

10. Terrestrial Biomes Characterized by plant communities low tundra coniferous forest (taiga) cool desert cool grassland temperate deciduous forest temperate rain forest warm desert tropical deciduous forest warm grassland savanna tropical rain forest temperature rainfall high low high

11. How Is Life On Land Distributed? tropical rain forest desert tropical deciduous forest savanna and tropical scrub forest chaparral temperate deciduous forest temperate rain forest grasslandice tundra and alpine vegetation coniferous forest (taiga) 0° 30° S 60° S 30° N 60° N (equator)

12. Tropical rain forests near the equator, average temperature 77°F - 86°F rainfall ranges 100 to 160 inches annually dominated by huge broadleaf evergreen trees. Large areas of rain forest are found in South America, Africa, and Southeast Asia.

13. Tropical dry (deciduous) forests further from the equator, rainfall is not nearly as constant pronounced wet and dry seasons in the dry season, trees drop their leaves if they don’t get enough water, minimizing water loss The trees delay growth of new leaves until the drought passes.

14. Savannas grasses dominant vegetation rainy season: all the year’s precipitation falls; dry season: soil becomes hard and dusty.

15. Deserts areas with less than 10 inches of annual rainfall perennial plants : bushes or cacti with large, shallow root systems that quickly soak up soil moisture

16. Chaparral coastal regions that border on deserts rainfall is as much as 30 inches cool, wet winters alternate with hot, dry summers. vegetation consists of small trees or large bushes, such as sages and evergreen oaks.

17. Grasslands (prairie) located in the centers of continents receive 10 to 30 inches of rain annually continuous cover of grass and virtually no trees fertile soil

18. Temperate deciduous forests Precipitation is higher than in grasslands soil retains enough moisture for trees to grow resulting forest shades out grasses. cold winters and long periods of below- freezing weather

19. Temperate rain forests U.S. Pacific Coast,southeastern coast of Australia and the southwestern coast of New Zealand tremendous amount of rain and trees do not shed their leaves in the fall Conifer trees; little light reaches the forest floor

20. Taiga North of the grasslands and temperate forests northern coniferous forest winters are long and cold, growing season is short diversity of life is low

21. Tundra vast treeless regions bordering the Arctic Ocean winter temperatures often reach –40°F or below, rainfall averages 10 inches permafrost, a permanently frozen layer of soil that lies no more than about 1.5 feet below the surface

22. How Is Life On Land Distributed? tropical rain forest desert tropical deciduous forest savanna and tropical scrub forest chaparral temperate deciduous forest temperate rain forest grasslandice tundra and alpine vegetation coniferous forest (taiga) 0° 30° S 60° S 30° N 60° N (equator)

23. Human Influence on BIOMES The Human Effect