1. Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings PowerPoint Lectures for Biology: Concepts and Connections, Fifth Edition – Campbell, Reece, Taylor, and Simon Lectures by Chris Romero Chapter 34 The Biosphere: An Introduction to Earth’s Diverse Environments

2. Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Ecology –Is the scientific study of the interactions of organisms with their environments

3. Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings 34.1 Ecologists study how organisms interact with their environment at several levels At the organismal level –Ecologists may examine how one kind of organism meets the challenges of its environment Figure 34.1

4. Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings At the population level –Ecologists might study factors that limit population size At the community level –An ecologist might focus on interspecies interactions

5. Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Ecosystem interactions involve –Living (biotic) communities and nonliving (abiotic) physical and chemical factors

6. Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings THE BIOSPHERE 34.2 The biosphere is the total of all of Earth’s ecosystems The biosphere –Is the global ecosystem Figure 34.2A

7. Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Patchiness of the environment –Characterizes the biosphere Figure 34.2B

8. Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings CONNECTION 34.3 Environmental problems reveal the limits of the biosphere Human activities, including the widespread use of chemicals –Affect all parts of the biosphere –DDT, Agent Orange, Dioxin, atrazene, herbicides (Round-Up) Poison the ground and water –Waste (both human and solid)

9. Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings 34.4 Physical and chemical factors influence life in the biosphere Abiotic factors determining the biosphere’s structure and dynamics include –Solar energy, water, temperature, wind, and disturbances Figure 34.4

10. Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings 34.5 Organisms are adapted to abiotic and biotic factors by natural selection Unique adaptations –Allow the survival of organisms in particular habitats Figure 34.5

11. Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Biotic factors, such as predation and competition –Can lead to the evolution of adaptations by natural selection

12. Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings 34.6 Regional climate influences the distribution of biological communities Most climatic variations –Are due to the uneven heating of Earth’s surface as it orbits the sun Low angle of incoming sunlight Sunlight strikes most directly Low angle of incoming sunlight Atmosphere 60ºS South Pole Tropic of Capricorn 30ºS 0º (equator) 30ºN Tropic of Cancer North Pole 60ºN Figure 34.6A

13. Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings The tilt of the Earth’s axis –Causes the changes of the seasons in the northern and southern hemispheres June solstice (Northern Hemisphere tilts toward sun) March equinox (equator faces sun directly) Constant tilt of 23.5º September equinox December solstice (Northern Hemisphere tilts away from sun) Figure 34.6B

14. Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings The uneven heating of the Earth –Also sets up patterns of precipitation and prevailing winds Descending dry air absorbs moisture Trade winds Ascending moist air releases moisture Trade winds Descending dry air absorbs moisture Doldrums Temperate zone Tropics Temperate zone 30º 23.5º 0º 23.5º 30º 60ºN 30ºN 30ºS Figure 34.6C, D

15. Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Ocean currents –Influence coastal climate Fresno 104º Paso Robles 93º Bakersfield 106º Death Valley 119º Pacific Ocean Santa Barbara 75º Los Angeles (Airport) 74º San Diego 75º 40 miles San Bernardino 101º Riverside 91º Palm Springs 104º Burbank 86º Santa Ana 84º Key 70s (ºF) 80s 90s 100s 110s Figure 34.6E

16. Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Pacific Ocean Coast Range Wind direction Sierra Nevada East Figure 34.6F Landforms such as mountains –Affect rainfall

17. Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings TERRESTRIAL BIOMES 34.9 Terrestrial biomes reflect regional variations in climate Temperature and rainfall –Mainly determine the terrestrial biomes

18. Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Major terrestrial biomes 30ºN Tropic of Cancer Equator Tropic of Capricorn 30ºS Tropical forest Savanna Desert Chaparral Temperate grassland Temperate broadleaf forest Coniferous forest Tundra High mountains Polar ice Figure 34.9

19. Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings 34.10 Tropical forests cluster near the equator Tropical rain forests –Are the most diverse ecosystem Figure 34.10

20. Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings 34.11 Savannas are grasslands with scattered trees Savannas –Are dry and warm Figure 34.11

21. Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings 34.12 Deserts are defined by their dryness Deserts –Are the driest biomes Figure 34.12

22. Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings 34.13 Spiny shrubs dominate the chaparral The chaparral –Is a shrubland with cool, rainy winters and dry, hot summers Figure 34.13

23. Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings 34.14 Temperate grasslands include the North American prairie Temperate grasslands –Are found where winters are cold Figure 34.14

24. Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings 34.15 Broadleaf trees dominate temperate forests Temperate broadleaf forests grow throughout midlatitude regions –Where there is sufficient moisture to support the growth of large trees Figure 34.15

25. Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings 34.16 Coniferous forests are often dominated by a few species of trees The northern coniferous forest, or taiga –Is found where there are short summers, and long, snowy winters Figure 34.16

26. Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings 34.17 Long, bitter-cold winters characterize the tundra Arctic tundra –Is a treeless biome characterized by extreme cold, wind, and permafrost Figure 34.17

27. Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Alpine tundra –Occurs above the treeline on high mountains