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. • Latitude and elevation help determine climate. Earth’s Current Climate Zones Figure 7-2 Animation: Climate and Ocean Currents Map Animation: Air Circulation and Climate 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 Energy Transfer by Convection in the Atmosphere 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 Arctic tundra Evergreen 60°coniferous forest Temperate deciduous forest and grassland 30°Tropical Desert POLAR CELLS Cell 2 North Cool, dry air falls Cell 1 North deciduous forest 0°Equator Tropical deciduous 30°forest Tropical rain forest Desert Temperate deciduous 60°forest and grassland Cell 1 South Cool, dry air falls Cell 2 South Polar cap Cold, dry air falls HADLEY CELLS FERREL CELLS Moist air rises — rain Cell 3 South Fig. 7-6, p. 144 Animation: Air Circulation 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 Flow of Energy to and from the Earth Animation: Greenhouse effect Animation: Increasing Greenhouse Gases 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. Animation: Upwelling Along Western Coasts Animation: El Nino Southern Oscillation 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 Animation: Coastal Breezes 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) Temperate grassland Tropical grassland (savanna) Chaparral Coniferous forest Temperate deciduous forest Tropical forest Desert Tropic of Capricorn Fig. 5-9, p. 106 Natural Capital: Average Precipitation and Average Temperature as Limiting Factors Figure 5-10 Polar Tundra Subpolar Temperate Coniferous forest Desert Deciduous Forest Grassland Chaparral Tropical Desert Rain forest Savanna Tropical seasonal forest Scrubland 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 Climate Graphs of Three Types of Deserts 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 Climate Graphs of Tropical, Temperate, and Cold Grasslands 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 Chaparral Vegetation in Utah, U.S. Video: Caribou Video: Tundra Flyover 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 There Are Three Major Types of Forests (3) Temperate deciduous forests • • • • Temperature and moisture Broad-leaf trees Slow rate of decomposition: significance Impact of human activities There Are Three Major Types of Forests (4) Evergreen coniferous forests: boreal and taigas • • • • Temperature and moisture Few species of cone: bearing trees Slow decomposition: significance Taiga is the intermediary between boreal forest and tundra Coastal coniferous forest Dry Coniferous forest Temperate rain forests Climate Graphs of Tropical, Temperate, and Cold Forests Stepped Art Fig. 7-15, p. 154 Some Components and Interactions in a Tropical Rain Forest Ecosystem Ocelot Harpy eagle Blue and gold macaw Squirrel monkeys Climbing monstera palm Katydid Green tree Slaty-tailed snake trogon Tree frog Ants Bacteria Bromeliad Fungi Producer to primary consumer Primary to secondary consumer Secondary to higher-level consumer All producers and consumers to decomposers Fig. 7-16, p. 155 Stratification of Specialized Plant and Animal Niches in a Tropical Rain Forest 45 40 Emergent layer Harpy eagle 35 Toco toucan Canopy Height (meters) 30 25 20 15 Under story Wooly opossum 10 Brazilian tapir 5 0 Black-crowned antpitta Shrub layer Ground layer Fig. 7-17, p. 156 Temperate Rain Forest in Washington State, U.S. Temperate Deciduous Forest Most of the trees survive winter by dropping their leaves, which decay slowly and produce a nutrientrich soil. Page S56 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— why does this allow them to survive? Page S57 Video: Sequoias Mountains Play Important Ecological Roles Majority of the world’s forests Habitats for endemic species Help regulate the earth’s climate Can affect sea levels Major storehouses of water • Role in hydrologic cycle Mount Rainier National Park in Washington State, U.S. Humans Impact Terrestrial Biomes Human activities have damaged or disturbed more than half of the world’s terrestrial ecosystems. Humans have had a number of specific harmful effects on the world’s deserts, grasslands, forests, and mountains. Major Human Impacts on Terrestrial Ecosystems NATURAL CAPITAL DEGRADATION Major Human Impacts on Terrestrial Ecosystems Deserts Grasslands Forests Clearing for Large desert cities Conversion agriculture, to cropland Soil destruction by Release of CO2 livestock grazing, off-road vehicles to atmosphere timber, and urban from burning development Soil salinization grassland Conversion of from irrigation diverse forests to Overgrazing tree plantations Depletion of by livestock groundwater Damage from offOil production road vehicles Land disturbance and off-road and pollution from vehicles in Pollution of mineral extraction arctic tundra forest streams Mountains Agriculture Timber extraction Mineral extraction Hydroelectric dams and reservoirs Increasing tourism Urban air pollution Increased ultraviolet radiation from ozone depletion Soil damage from off-road vehicles Fig. 7-20, p. 158 Video: Eagle Fishing Video: Gopher Video: Grizzly Bears Video: Owl Hunting