1. Chapter 7 Climate and Terrestrial Biodiversity

2. Core Case Study Blowing in the Wind: A Story of Connections
Wind connects most life on earth.
Keeps tropics from being unbearably hot.
Prevents rest of world from freezing.
Figure 7-1

3. 7-1 What Factors Influence Climate?
Concept 7-1 An area's climate is determined mostly by solar radiation, the earth’s rotation, global patterns of air and water movement, gases in the atmosphere, and the earth’s surface features. 3

4. CLIMATE: A BRIEF INTRODUCTION
Weather is a local area’s short-term physical conditions such as temperature and precipitation.
Climate is a region’s average weather conditions over a long time.
Latitude and elevation help determine climate.

5. Figure 5.2
Natural capital: generalized map of the earth’s current climate zones, showing the major contributing ocean currents and drifts and upwelling areas.
Fig. 7-2

6. Animation: Climate and Ocean Currents Map
PLAY
ANIMATION

7. Solar Energy and Global Air Circulation: Distributing Heat
Global air circulation is affected by the uneven heating of the earth’s surface by solar energy, seasonal changes in temperature and precipitation.

8. Video: Seasonal Variation
PLAY
VIDEO

9. Corilois Effect Solar energy
Cold deserts
Air cools and descends at lower latitudes.
Westerlies
Forests
30°N
Northeast trades
Hot deserts
Warm air rises and moves toward the poles.
Forests 0°
Solar energy
Equator
Air cools and descends at lower latitudes.
Southeast trades
Hot deserts
30°S
The highest solar energy input is at the equator.
Figure 7.3
Global air circulation. The largest input of solar energy occurs at the equator. As this air is heated it rises and moves toward the poles. However, the earth’s rotation deflects the movement of the air over different parts of the earth. This creates global patterns of prevailing winds that help distribute heat and moisture in the atmosphere.
Westerlies
Forests
Cold deserts
60°S
Fig. 7-3, p. 142

10. Convection Currents
Global air circulation is affected by the properties of air water, and land.
Figure 7-4

11. Global Air Circulation, Ocean Currents, and Biomes
Fig 7.6 11

12. Animation: Air Circulation and Climate
PLAY
ANIMATION

13. Ocean Currents: Distributing Heat and Nutrients
Global warming:
Considerable scientific evidence and climate models indicate that large inputs of greenhouse gases from anthropogenic activities into the troposphere can enhance the natural greenhouse effect and change the earth’s climate in your lifetime.

14. (b) The earth's surface absorbs much of the incoming solar radiation
(a) Rays of sunlight
penetrate the lower
atmosphere and
warm the earth's
surface.
(b) The earth's surface absorbs
much of the incoming solar radiation
and degrades it to longer-wavelength
infrared (IR) radiation, which rises
into the lower atmosphere. Some of this
IR radiation escapes into space as heat,
and some is absorbed by molecules of
greenhouse gases and emitted as even
longer-wavelength IR radiation, which
warms the lower atmosphere.
(c) As concentrations of
greenhouse gases rise,
their molecules absorb
and emit more infrared
radiation, which adds
more heat to the lower
atmosphere.
Figure 5.7
Natural capital: the natural greenhouse effect. When concentrations of greenhouse gases in the atmosphere rise, the average temperature of the troposphere rises. (Modified by permission from Cecie Starr, Biology: Concepts and Applications, 4th ed., Pacific Grove, Calif.: Brooks/Cole, 2000)

15. Connected Deep and Shallow Ocean Currents
Fig 7-5 15

16. Rain Shadow Effect On the leeward side of the mountain range, air
descends, warms, and
Releases little moisture.
Prevailing winds
pick up moisture
from an ocean.
On the windward
side of a mountain range,
air rises, cools, and
releases moisture.
Dry habitats
Moist habitats
Figure 5.8
Natural capital: The rain shadow effect is a reduction of rainfall on the sides of mountains facing away from prevailing surface winds. Warm, moist air in prevailing onshore winds loses most of its moisture as rain and snow on the windward (wind-facing) slopes of a mountain range. This leads to semiarid and arid conditions on the leeward side of the mountain range and the land beyond. The Mojave Desert in the U.S. state of California and Asia’s Gobi Desert were both created by this effect.
Fig. 7-7

17. 7-2 How Does Climate Affect the Nature and Locations of Biomes?
Concept 7-2 Differences in average annual precipitation and temperature lead to the formation of tropical, temperate, and cold deserts, grasslands, and forests, and largely determine their locations. 17

18. BIOMES: CLIMATE AND LIFE ON LAND
Different climates lead to different communities of organisms, especially vegetation.
Biomes – large terrestrial regions characterized by similar climate, soil, plants, and animals.
Each biome contains many ecosystems whose communities have adapted to differences in climate, soil, and other environmental factors.

19. Tropic of Cancer Equator Tropic of Capricorn High mountains Polar ice
Polar grassland (arctic tundra)
Tropic of
Capricorn
Temperate grassland
Figure 5.9
Natural capital: the earth’s major biomes—the main types of natural vegetation in various undisturbed land areas—result primarily from differences in climate. Each biome contains many ecosystems whose communities have adapted to differences in climate, soil, and other environmental factors. Human ecological footprints (Figures 3 and 4 on pp. S12–S15 in Supplement 4) have removed or altered much of the natural vegetation in some areas for farming, livestock grazing, lumber and fuelwood, mining, and construction.
Tropical grassland (savanna)
Chaparral
Coniferous forest
Temperate deciduous forest
Tropical forest
Desert
Fig. 7-8

20. BIOMES: CLIMATE AND LIFE ON LAND
Biome type is determined by precipitation, temperature and soil type
Figure 7-10

21. BIOMES: CLIMATE AND LIFE ON LAND
Parallel changes occur in vegetation type occur when we travel from the equator to the poles or from lowlands to mountaintops.
Figure 7-9

22. DESERT BIOMES
Deserts are areas where evaporation exceeds precipitation.
Deserts have little precipitation and little vegetation.
Found in tropical, temperate and polar regions.
Desert plants have adaptations that help them stay cool and get enough water.

23. DESERT BIOMES
Variations in annual temperature (red) and precipitation (blue) in tropical, temperate and cold deserts.
Figure 7-11

24. DESERT BIOMES
The flora and fauna in desert ecosystems adapt to their environment through their behavior and physiology.

25. GRASSLANDS AND CHAPARRAL BIOMES
Grasslands (prairies) occur in areas too moist for desert and too dry for forests.
Savannas are tropical grasslands with scattered tree and herds of hoofed animals.

26. Climate Graphs of Tropical, Temperate, and Cold Grasslands
Fig 7-12 26

27. Temperate Grasslands
Temperate tall-grass prairie ecosystem in North America.

28. Chaparral
Figure 7.14
Chaparral vegetation in the U.S. state of Utah and a typical climate graph.
Stepped Art
Fig. 7-14, p. 152

29. FOREST BIOMES
Forests have enough precipitation to support stands of trees and are found in tropical, temperate, and polar regions.

30. Climate Graphs of Tropical, Temperate, and Cold Forests
Fig 7-15 30

31. Tropical Rain Forest
Tropical rain forests have heavy rainfall and a rich diversity of species.
Found near the equator.
Have year-round uniformity warm temperatures and high humidity.
Figure 7-16

32. Stratification of Specialized Plant and Animal Niches in a Tropical Rain Forest
Fig 7-17 32

33. Evergreen Coniferous Forests
Consist mostly of cone-bearing evergreen trees that keep their needles year-round to help the trees survive long and cold winters.

34. 7-3 How Have We Affected the Word’s Terrestrial Ecosystems?
Concept 7-3 In many areas, human activities are impairing ecological and economic services provided by the earth’s deserts, grasslands, forests, and mountains. 34

35. Major Human Impacts on Terrestrial Ecosystems
Fig 7-20 35