The Biosphere

1. The Biosphere Mader: Biology 8th Ed.

2. Outline • Climate and the Biosphere • Global Wind Circulation • Terrestrial Communities • Aquatic Communities • Life Zones • Lakes • Estuaries • Seashores • Oceans Mader: Biology 8th Ed.

3. Climate and the Biosphere • Climate refers to prevailing weather conditions in a region. • Dictated by temperature and precipitation. • Influenced by a multitude of factors including tilt of the earth’s axis and topography. Mader: Biology 8th Ed.

4. Effect of Solar Radiation • Distribution of solar energy due to a spherical planet and the rotation and path of the Earth around the sun affect how the wind blows and the amount of rainfall various regions receive. Mader: Biology 8th Ed.

5. Global Wind Circulation Mader: Biology 8th Ed.

6. Rain Shadow • As winds cross a coastal mountain range, they rise and release their moisture on the windward side of the mountain. • Leeward side receives relatively little rain and is said to lie in a rain shadow. Mader: Biology 8th Ed.

7. Formation of a Rain Shadow Mader: Biology 8th Ed.

8. Terrestrial Communities • Biome has a particular mix of plants and animals adapted to living under certain environmental conditions. • Often delineated by climate. • Temperature and precipitation varies according to latitude and altitude. Mader: Biology 8th Ed.

9. Biome Distribution Mader: Biology 8th Ed.

10. Climate and Biomes Mader: Biology 8th Ed.

11. Tundra • Arctic tundra encircles Earth just south of ice-covered polar seas in Northern Hemisphere. • Covers 20% of Earth’s land surface. • Trees are not found in the tundra because growing season is too short. • Roots cannot penetrate permafrost. Mader: Biology 8th Ed.

12. Tundra Mader: Biology 8th Ed.

13. Coniferous Forests • Taiga typifies coniferous forest with cone-bearing trees. • Trees well adapted to cold. • Leaves and bark have thick covering. • Needle-like leaves can withstand weight of heavy snowfall. • Temperate Rainforest (Old-Growth Forests) of Pacific Northwest. • Evergreen forest. Mader: Biology 8th Ed.

14. Temperate Deciduous Forests • Found south of taiga in eastern North America, eastern Asia, and much of Europe. • Well defined season with long growing seasons. • Tallest trees form a canopy. • Ground-life is plentiful. Mader: Biology 8th Ed.

15. Temperate Deciduous Forest Mader: Biology 8th Ed.

16. Tropical Forests • Found in equatorial regions. • Plentiful rainfall. • Most animals live in trees. • Abundant insect life. • Epiphytes grow in many areas. • Soils are nutrient-poor. • Rapid recycling of nutrients. • Swidden agriculture successful but destructive. Mader: Biology 8th Ed.

17. Shrublands • Tend to occur along coasts that have dry summers and receive most of their rainfall in the winter. • Shrubs adapted to withstand arid conditions. • Dense shrubland in California known as chaparral. Mader: Biology 8th Ed.

18. Grasslands • Grasslands occur where annual rainfall is greater than 25 cm, but generally insufficient to support trees. • Grasses well adapted to changing environment. • Temperate Grasslands • Savannas Mader: Biology 8th Ed.

19. Temperate Grassland Mader: Biology 8th Ed.

20. Savanna Mader: Biology 8th Ed.

21. Deserts • Usually found at latitudes of about 30o in both north and south hemispheres. • Descending winds lack moisture. • Annual rainfall less than 25 cm. • Large temperature differential between day and night. Mader: Biology 8th Ed.

22. Deserts Mader: Biology 8th Ed.

23. Aquatic Communities • Lakes • Bodies of water classified by their nutrient status. • Oligotrophic - Nutrient-poor. • Eutrophic - Nutrient-rich. • Lake Stratification • In temperate zones, deep lakes are stratified in the summer and winter. Mader: Biology 8th Ed.

24. Mader: Biology 8th Ed.

25. Life Zones • Plankton are important community components in fresh water and salt water. • Phytoplankton - Algae • Zooplankton - Animals • Life Zones • Littoral zone - Closest to shore. • Limnetic zone - Sunlit areas. • Profundal zone - Below light penetration. • Benthic zone - Soil-Water interface. Mader: Biology 8th Ed.

26. Zones of a Lake Mader: Biology 8th Ed.

27. Coastal Communities • Estuaries • Partially enclosed bodies of water where fresh water and seawater meet and mix. • Organisms must be able to adapt to changing salinity. • Estimated over half of all marine fishes develop in protective environment of estuaries. Mader: Biology 8th Ed.

28. Estuary Structure and Function Mader: Biology 8th Ed.

29. Seashores • Littoral zone lies between high and low water marks. • Littoral zone of rocky beach divided into subzones. • Organisms cannot attach to shifting, unstable sands; therefore nearly all permanent residents dwell underground. Mader: Biology 8th Ed.

30. Seacoasts Mader: Biology 8th Ed.

31. Oceans • Major ocean currents move heat from the equator to cooler parts of the biosphere. • Gulf Stream warms east coast of North America and parts of Europe. • El Nino Southern Oscillation • Cold upwelling off west coast of South America subsides. Mader: Biology 8th Ed.

32. Ocean Currents Mader: Biology 8th Ed.

33. Oceans • Pelagic Division • Neritic Province • High concentration of organisms due to sunlight penetration and supply of inorganic nutrients. • Coral Reefs • Oceanic Province • Lacks inorganic nutrients and thus does not have high concentration of phytoplankton. Mader: Biology 8th Ed.

34. Mader: Biology 8th Ed.

35. Oceans • Benthic Division • Includes organisms that live on or in the: • Continental Shelf (sublittoral zone) • Continental Slope (bathyal zone) • Abyssal Plain (Abyssal zone) • Interrupted by hydrothermal vents. • Organisms are dependent on debris floating down from above. Mader: Biology 8th Ed.

36. Review • Climate and the Biosphere • Global Wind Circulation • Terrestrial Communities • Aquatic Communities • Life Zones • Lakes • Estuaries • Seashores • Oceans Mader: Biology 8th Ed.

37. Mader: Biology 8th Ed.