Transcript Chapter 5
Chapter 5 Climate and Terrestrial Biodiversity Chapter Overview Questions What factors the earth’s climate? How does climate determine where the earth’s major biome’s are found? What are the major types of desert biomes? What are the major types of grassland biomes? Chapter Overview Questions (cont’d) What are the major types of forest and mountain biomes? How have human activities affected the world’s desert, grassland, forest, and mountain biomes? Updates Online The latest references for topics covered in this section can be found at the book companion website. Log in to the book’s e-resources page at www.thomsonedu.com to access InfoTrac articles. InfoTrac: Of Chicks and Frogs. Steven Pinker. Forbes, August 14, 2006 v178 i3 p40. InfoTrac: Nice Rats, Nasty Rats: Maybe It's All In the Genes. Nicholas Wade. The New York Times, July 25, 2006 pF1(L). InfoTrac: Ancient shrub unlocks a clue to Darwin's 'abominable mystery.’ The Christian Science Monitor, May 18, 2006 p02. The Jane Goodall Institute Natural History Museum: Ancient Birds 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 5-1 Wind: Case Study Wind blows Sahara desert nutrients to Bahamas and Brazil. Wind blows iron from Gobi Desert to Pacific Ocean which nourishes the phytoplankton SUVs destroy sand crust and wind blows increased amounts of sediment Wind transports viruses, molds, bacteria and fungi 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. Earth’s Current Climate Zones Figure 5-2 Solar Energy and Global Air Circulation: Distributing Heat FOUR FACTORS that determine global air patterns 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. Figure 5-3 Spring (sun aims directly at equator) Winter (northern hemisphere 23.5 ° tilts away from sun) Solar radiation Summer (northern hemisphere tilts toward sun) Fall (sun aims directly at equator) Fig. 5-3, p. 102 Coriolis Effect Global air circulation is affected by the rotation of the earth on its axis. Figure 5-4 Cold deserts Westerlies Northeast trades Forests Hot deserts Forests Equator Southeast trades Westerlies Hot deserts Forests Cold deserts Fig. 5-4, p. 102 Convection Currents Global air circulation is affected by the properties of air water, and land. Figure 5-5 LOW PRESSURE Cool, dry air HIGH PRESSURE Heat released radiates to space Condensation Falls, is compressed, warms and precipitation Rises, expands, cools Warm, dry air Hot, wet air Flows toward low pressure, picks up moisture and heat HIGH Moist surface warmed PRESSURE by sun LOW PRESSURE Fig. 5-5, p. 103 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 5-6 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 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 Moist air rises, cools, and releases Moisture as rain Moist air rises — rain Cell 3 South Fig. 5-6, p. 103 4 Factors affecting Global Air Circulation 1. Uneven heating of the Earth’s surface 1. “Denser” light shines on equator 2. Seasonal changes in temperature and precipitation 3. Rotation of the Earth on its axis 1. Equator spins faster than poles creating Coriolis effect 4. Properties of air, water and land 1. Cyclical convection cells created Ocean Currents: Distributing Heat and Nutrients Ocean currents influence climate by distributing heat from place to place and mixing and distributing nutrients. Figure 5-7 (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. Fig. 5-7, p. 104 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. ATMOSPHERE GASES AND CLIMATE Greenhouse gases allows visible light and UV to pass through, but absorbs some of the returning Infrared light and returns it at a longer wavelength GREENHOUSE GASES Water vapor: H2O Carbon Dioxide: CO2 Methane: CH4 Nitrous oxide: N2O GREENHOUSE GASES Could result in: change in precipitation patterns shift in cropland rise in sea levels change in areas where some plants and animals live 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 A RAIN SHADOW IS FORMED 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. Dry habitats Moist habitats Fig. 5-8, p. 105 Heat and Water Heat is absorbed and released more slowly by water than by land This means coastal areas and large lakes have weather moderated by the water. 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. BIOMES: CLIMATE AND LIFE ON LAND 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 Climate change is part of history • Change caused by solar output, volcanic eruptions, and continents moving. • 5,000 years ago part of Saharan Desert was fertile • 15,000 years ago arid Western US was rainy and contained many lakes • Evidence that we are changing climate in 50-100 years BIOMES: CLIMATE AND LIFE ON LAND Biome type is determined by precipitation, temperature and soil type 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 • Tropical = hot • Temperate = moderate • Polar = cold Biomes • Biomes are not uniform • Contain a mosaic of patches with somewhat different biological communities with similarities unique to the biome 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 Elevation Mountain ice and snow Tundra (herbs, lichens, mosses) Coniferous Forest Latitude Deciduous Forest Tropical Forest Tropical Forest Deciduous Coniferous Tundra (herbs, Forest Forest lichens, mosses) Polar ice and snow Fig. 5-11, p. 108 DESERT BIOMES Deserts are areas where evaporation exceeds precipitation. Deserts have little precipitation and little vegetation. Where are they found? Found in tropical, temperate and polar regions. Desert plants have adaptations that help them stay cool and get enough water. DESERT BIOMES Variations in annual temperature (red) and precipitation (blue) in tropical, temperate and cold deserts. Figure 5-12 Deserts Cover about 30% of the earth’s land surface Found mainly in tropical and subtropical regions Largest Deserts found in the interiors of continents, far from moist sea air Or form in Rain Shadows Deserts not Desserts Sun bakes ground in day At night, heat radiates quickly from rocks to atmosphere Without moisture in the soil, the heat is not stored This allows you to bake in the day, and freeze during the nights Hot and Dry most of the year. Example: Sahara and Namib Freezing point Month Mean monthly precipitation (mm) Mean monthly temperature (C) Tropical Desert Fig. 5-12a, p. 109 Day temps high in summer and low in winter. Example: Mojave desert Freezing point Month Mean monthly precipitation (mm) Mean monthly temperature (C) Temperate Desert Fig. 5-12b, p. 109 Cold Deserts: Cold winters, warm summers, sparse vegetation Freezing point Month Mean monthly precipitation (mm) Mean monthly temperature (°C) Polar Desert Example: Gobi Desert in China Fig. 5-12c, p. 109 DESERT BIOMES The flora and fauna in desert ecosystems adapt to their environment through their behavior and physiology. Figure 5-13 Red-tailed hawk Gambel's Quail Yucca Jack rabbit Agave Collared lizard Prickly pear cactus Roadrunner Darkling Beetle Bacteria Diamondback rattlesnake Producer to primary consumer Fungi Kangaroo rat Primary to secondary consumer Secondary to higher-level consumer All producers and consumers to decomposers Fig. 5-13, p. 110 Deserts • Evergreen plants conserve water by having wax coated leaves that reduce water loss • Wildflowers and grasses store much of their biomass in seeds that remain inactive until they receive enough water to germinate Deserts • Most animals are small • They hide in cool burrows or rocky crevices by day and come out at night or early morning • Others are dormant during extreme heat • Insects and reptiles have thick outer coverings to minimize water loss – Their wastes are dry or concentrated urine Deserts are Fragile • • • • • Soils take a long time to heal Low diversity Slow nutrient cycling Slow plant growth Tank tracks are still visible in the Mojave desert from 1940s GRASSLANDS AND CHAPARRAL BIOMES Variations in annual temperature (red) and precipitation (blue). Figure 5-14 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. Maintained by seasonal drought, grazing and occasional fires Savanna Freezing point Month Mean monthly precipitation (mm) Mean monthly temperature (C) Tropical grassland (savanna) Overgrazing and use of firewood is converting savannas to deserts Fig. 5-14a, p. 112 Prairies Fires burn top layer of plants, but not the roots Freezing point Month Mean monthly precipitation (mm) Mean monthly temperature (C) Temperate grassland Netted roots hold mesh of organic material in, unless it is plowed and allowed to blow away Fig. 5-14b, p. 112 Temperate Grasslands The cold winters and hot dry summers have deep and fertile soil that make them ideal for growing crops and grazing cattle. Figure 5-15 Temperate Grasslands • Most have been converted to cropland • Or raise cattle • Or build towns and cities Temperate Grasslands Temperate tallgrass prairie ecosystem in North America. Figure 5-16 Golden eagle Pronghorn antelope Grasshopper sparrow Coyote Grasshopper Blue stem grass Prairie dog Bacteria Fungi Prairie Coneflower Producer to primary consumer Primary to secondary consumer Secondary to higher-level consumer All producers and consumers to decomposers Fig. 5-15, p. 113 Arctic Tundra Freezing point Month Mean monthly precipitation (mm) Mean monthly temperature (C) Polar grassland (arctic tundra) Fig. 5-14c, p. 112 Polar Grasslands Polar grasslands are covered with ice and snow except during a brief summer. Figure 5-17 Long-tailed jaeger Grizzly bear Caribou Horned lark Willow ptarmigan Mosquito Snowy owl Arctic fox Dwarf Willow Lemming Mountain Cranberry Moss campion Producer to primary consumer Primary to secondary consumer Secondary to higher-level consumer All producers and consumers to decomposers Fig. 5-17, p. 114 Arctic Tundra • • • • • • Treeless Bitterly cold winters Frigid winds Covered by ice and snow Long, dark winters Low levels of precipitation Arctic Tundra • Thick, spongy mat of low-growing plants – Grasses, mosses, lichens, and dwarf shrubs • Most Growth occurs in 6-8 weeks of summer PERMAFROST • Water trapped in soil that stays frozen for more than 2 years – Prevents summer melt from soaking in and creates summer lakes, marshes, bogs and ponds • Insects and migratory birds thrive in summer wetlands • Global Warming causing parts of permafrost to melt (Alaska) Tundra Scars • Short growing season leads to slow recovery • Arctic exploration and development: oil and diamonds – Leads to scars that will last for centuries Chaparral Chaparral has a moderate climate but its dense thickets of spiny shrubs are subject to periodic fires. Figure 5-18 Temperate Shrubland: Chaparral Dense growth of low-growing evergreen shrubs and occasional small trees with leathery leaves Soil is thin and not very fertile Characterized by Manzanita bushes • Red bark that peels off (look for it on the hike) Found in certain coastal areas (SB and LA too) Long, dry summers lead to flammable conditions You are on your own for the forest biomes Don’t forget to study about all of the biodiversity FOREST BIOMES Variations in annual temperature (red) and precipitation (blue) in tropical, temperate, and polar forests. Figure 5-19 Freezing point Month Mean monthly precipitation (mm) Mean monthly temperature (C) Tropical rain forest Fig. 5-19a, p. 116 Freezing point Month Mean monthly precipitation (mm) Mean monthly temperature (C) Temperate deciduous forest Fig. 5-19b, p. 116 Freezing point Month Mean monthly precipitation (mm) Mean monthly temperature (C) Polar evergreen coniferous forest (boreal forest, taiga) Fig. 5-19c, p. 116 FOREST BIOMES Forests have enough precipitation to support stands of trees and are found in tropical, temperate, and polar regions. 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 5-20 Ocelot Harpy eagle Blue and gold macaw Climbing monstera palm Slaty-tailed trogon Squirrel monkeys Katydid Green tree snake 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. 5-20, p. 117 Tropical Rain Forest Filling such niches enables species to avoid or minimize competition and coexist Figure 5-21 Emergent layer Harpy eagle Toco toucan Canopy Understory Woolly opossum Shrub layer Brazilian tapir Black-crowned antipitta Ground layer Fig. 5-21, p. 118 Temperate Deciduous Forest Most of the trees survive winter by dropping their leaves, which decay and produce a nutrientrich soil. Figure 5-22 Broad-winged hawk Hairy Woodpecker Gray Squirrel White oak White-tailed deer White-footed mouse Metallic wood-boring beetle and Larvae Mountain Winterberry Shagbark hickory Fungi May beetle Long-tailed weasel Bacteria Producer to primary consumer Racer Wood frog Primary to secondary consumer Secondary to higher-level consumer All producers and consumers to decomposers Fig. 5-22, p. 120 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. Figure 5-23 Great horned owl Blue jay Marten Balsam fir Moose White Spruce Wolf Bebb willow Pine sawyer beetle and larvae Snowshoe hare Fungi Starflower Bacteria Producer to primary consumer Primary Secondary to to secondary higher-level consumer consumer Bunchberry All producers and consumers to decomposers Fig. 5-23, p. 121 Temperate Rain Forests Coastal areas support huge cone-bearing evergreen trees such as redwoods and Douglas fir in a cool moist environment. Figure 5-24 Temperate Rain Forest Mendocino and Humboldt County Many beautiful redwoods It is worth your time to visit the area Jedediah Smith Park with the Smith River is one of my favorites I used to live in Richardson Grove State Park on Highway 1 at the south end of Humboldt MOUNTAIN BIOMES High-elevation islands of biodiversity Often have snowcovered peaks that reflect solar radiation and gradually release water to lowerelevation streams and ecosystems. Figure 5-25 HUMAN IMPACTS ON 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. Human Impacts Estimated that we use, waste or destroy about 10-55% of net primary productivity or terrestrial ecosystems Producers determine the number of consumers 60% of terrestrial ecosystems are being degraded or used unsustainably Natural Capital Degradation Desert Large desert cities Soil destruction by off-road vehicles Soil salinization from irrigation Depletion of groundwater Land disturbance and pollution from mineral extraction Fig. 5-26, p. 123 Natural Capital Degradation Grasslands Conversion to cropland Release of CO2 to atmosphere from grassland burning Overgrazing by livestock Oil production and off-road vehicles in arctic tundra Fig. 5-27, p. 123 Natural Capital Degradation Forests Clearing for agriculture, livestock grazing, timber, and urban development Conversion of diverse forests to tree plantations Damage from off-road vehicles Pollution of forest streams Fig. 5-28, p. 124 Natural Capital Degradation 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. 5-29, p. 124 Tentative Homework learn pg 123-124 • • • • Critical Thinking #2 (will help you identify items in a system) #4 (similar to FRQ on the exam) #6 (helps you apply the information that you read) • Projects #1 (knowing about your environment can help you answer questions on the FRQ section