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Chapter 5. Climate and Terrestrial Biodiversity. Opening Video: Cloud Forests. Weather and Climate. 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.
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Chapter 5 Climate and Terrestrial Biodiversity
Weather and Climate 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.
Earth’s Current Climate Zones Figure 7-2
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.
Winter (northern hemisphere tilts away from sun) 23.5 ° Spring (sun aims directly at equator) Solar radiation Summer (northern hemisphere tilts toward sun) Fall (sun aims directly at equator)
Coriolis Effect – Global air circulation is affected by Earth’s rotation
Convection Cells Heat and moisture are distributed over the earth’s surface by vertical currents, which form six giant convection cells at different latitudes. Figure 7-6
Cell 3 North Cold, dry air falls Moist air rises — rain Polar cap Cell 2 North Arctic tundra Evergreen coniferous forest 60° Cool, dry air falls Temperate deciduous forest and grassland 30° Desert Cell 1 North Tropical deciduous forest POLAR CELLS FERREL CELLS Tropical rain forest 0° Equator HADLEY CELLS Tropical deciduous forest 30° Desert Cell 1 South Temperate deciduous forest and grassland Cool, dry air falls 60° Cell 2 South Polar cap Cold, dry air falls Moist air rises — rain Cell 3 South Fig. 7-6, p. 144
Air Pressure, Fronts and Precipitation Pressure: Measured in mb or inches of Hg Low Pressure: Converging, CCW in N.H. High Pressure: Diverging, CW in N.H. Fronts: Cold, Warm, Stationary, Occluded Severe Weather: Thunderstorms, tornadoes, hurricanes
Greenhouse Gases Warm the Lower Atmosphere Greenhouse gases H2O CO2 CH4 N2O Greenhouse effect Human-enhanced global warming
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.
Topography and Local Climate:Land Matters Interactions between land and oceans and disruptions of airflows by mountains and cities affect local climates. Figure 5-8
Prevailing winds pick up moisture from an ocean. On the windward side of a mountain range, air rises, cools, and releases moisture. On the leeward side of the mountain range, air descends, warms, and releases little moisture. Fig. 7-7, p. 145
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.
Earth’s Major Biomes Figure 5-9
Tropic of Cancer Equator High mountains Polar ice Polar grassland (arctic tundra) Tropic of Capricorn Temperate grassland Tropical grassland (savanna) Chaparral Coniferous forest Temperate deciduous forest Tropical forest Desert Fig. 5-9, p. 106
Natural Capital: Average Precipitation and Average Temperature as Limiting Factors Figure 5-10
Cold Polar Tundra Subpolar Temperate Coniferous forest Decreasing temperature Desert Deciduous Forest Grassland Tropical Chaparral Hot Desert Savanna Wet Rain forest Dry Tropical seasonal forest Scrubland Decreasing precipitation Fig. 5-10, p. 107
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 5-11
Science Focus: Staying Alive in the Desert Plant adaptations Animal strategies and adaptations
There Are Three Major Types of Deserts Tropical deserts Temperate deserts Cold deserts Fragile ecosystem Slow plant growth Low species diversity Slow nutrient recycling Lack of water
Stepped Art Fig. 7-11, p. 149
Video: Desertification in China • From ABC News, Environmental Science in the Headlines, 2005 DVD.
Key Organisms in a Desert Food Web The flora and fauna in desert ecosystems adapt to their environment through their behavior and physiology. Page S53
There Are Three Major Types of Grasslands (1) Tropical Temperate Cold (arctic tundra)
There Are Three Major Types of Grasslands (2) Tropical Savanna Grazing animals Browsing animals Temperate Tall-grass prairies Short-grass prairies
There Are Three Major Types of Grasslands (3) Arctic tundra: fragile biome Adaptations of plants and animals Permafrost Alpine tundra
Stepped Art Fig. 7-12, p. 151
Monoculture Crop Replacing Biologically Diverse Temperate Grassland
Temperate Shrubland: Nice Climate, Risky Place to Live Chaparral Near the sea: nice climate Prone to fires in the dry season
Key Organisms in Temperate Grasslands Temperate tall-grass prairie ecosystem in North America. Page S54
Polar Grasslands Polar grasslands are covered with ice and snow except during a brief summer. Page S55
There Are Three Major Types of Forests (1) Tropical Temperate Cold Northern coniferous and boreal
There Are Three Major Types of Forests (2) Tropical rain forests Temperature and moisture Stratification of specialized plant and animal niches Little wind: significance Rapid recycling of scarce soil nutrients Impact of human activities