Climate and Terrestrial Biodiversity Chapter 6 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?

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

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 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

(sun aims directly at equator) Winter (northern hemisphere tilts away from sun) Spring (sun aims directly at equator) 23.5 ° Solar radiation Summer (northern hemisphere tilts toward sun) Figure 5.3 Natural capital: as the planet makes its annual revolution around the sun on an axis tilted about 23.5°, various regions are tipped toward or away from the sun. The resulting variations in the amount of solar energy reaching the earth create the seasons in the northern and southern hemispheres. 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 Forests Northeast trades Hot deserts Forests Equator Figure 5.4 Natural capital: because of the Coriolis effect the earth’s rotation deflects the movement of the air over different parts of the earth, creating global patterns of prevailing winds that help distribute heat and moisture in the troposphere. Southeast trades Hot deserts Forests Westerlies 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

Heat released radiates to space Moist surface warmed by sun LOW PRESSURE HIGH PRESSURE Heat released radiates to space Condensation and precipitation Cool, dry air Falls, is compressed, warms Rises, expands, cools Warm, dry air Hot, wet air Figure 5.5 Natural capital: transfer of energy by convection in the troposphere. Convection occurs when hot and wet warm air rises, cools, and releases moisture as precipitation and heat (right side). Then the more dense cool and dry air sinks, gets warmer, and picks up moisture as it flows across the earth’s surface to begin the cycle again. Flows toward low pressure, picks up moisture and heat HIGH PRESSURE Moist surface warmed 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

Tropical deciduous forest Cold, dry air falls Cell 3 North 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 Moist air rises, cools, and releases Moisture as rain 0° Equator Tropical rain forest Tropical deciduous forest 30° Desert Figure 5.6 Natural capital: global air circulation and biomes. Heat and moisture are distributed over the earth’s surface by vertical currents, which form six giant convection cells at different latitudes. The resulting uneven distribution of heat and moisture over the planet’s surface leads to the forests, grasslands, and deserts that make up the earth’s biomes. 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. 5-6, p. 103

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

(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) 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.

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

Dry habitats Moist habitats 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 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. 5-8, p. 105

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 Tropic of Capricorn High mountains Polar ice Polar grassland (arctic tundra) Tropic of Capricorn 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. Temperate grassland Tropical grassland (savanna) Chaparral Coniferous forest Temperate deciduous forest Tropical forest Desert Fig. 5-9, p. 106

BIOMES: CLIMATE AND LIFE ON LAND Biome type is determined by precipitation, temperature and soil type Figure 5-10

Decreasing precipitation Cold Polar Tundra Subpolar Temperate Coniferous forest Decreasing temperature Desert Deciduous Forest Grassland Tropical Chaparral Figure 5.10 Natural capital: average precipitation and average temperature, acting together as limiting factors over a period of 30 or more years, determine the type of desert, grassland, or forest biome in a particular area. Although the actual situation is much more complex, this simplified diagram explains how climate determines the types and amounts of natural vegetation found in an area left undisturbed by human activities. (Used by permission of Macmillan Publishing Company, from Derek Elsom, The Earth, New York: Macmillan, 1992. Copyright © 1992 by Marshall Editions Developments Limited) Hot Desert Wet Savanna 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

Elevation Latitude Tropical Forest Deciduous Forest Coniferous Forest Mountain ice and snow Tundra (herbs, lichens, mosses) Coniferous Forest Latitude Deciduous Forest Tropical Forest Figure 5.11 Natural capital: generalized effects of elevation (left) and latitude (right) on climate and biomes. Parallel changes in vegetation type occur when we travel from the equator to the poles or from lowlands to mountaintops. Tropical Forest Deciduous Forest Coniferous Forest Tundra (herbs, 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. Found in tropical, temperate and polar regions. Desert plants have adaptations that help them stay cool and get enough water.

Video: Desertification This video clip is available in CNN Today Videos for Environmental Science, 2004, Volume VII. Instructors, contact your local sales representative to order this volume, while supplies last.

DESERT BIOMES Variations in annual temperature (red) and precipitation (blue) in tropical, temperate and cold deserts. Figure 5-12

Tropical Desert Month Mean monthly temperature (C) Freezing point Mean monthly temperature (C) Mean monthly precipitation (mm) Figure 5.12 Natural capital: climate graphs showing typical variations in annual temperature (red) and precipitation (blue) in tropical, temperate, and cold deserts. Top photo shows a popular but destructive SUV rodeo in Saudi Arabia (tropical desert). Center photo shows saguaro cactus in the United States (temperate desert). Bottom photo shows a Bactrian camel in Mongolia’s Gobi (cold) desert. Month Fig. 5-12a, p. 109

Temperate Desert Month Mean monthly temperature (C) Freezing point Mean monthly temperature (C) Mean monthly precipitation (mm) Figure 5.12 Natural capital: climate graphs showing typical variations in annual temperature (red) and precipitation (blue) in tropical, temperate, and cold deserts. Top photo shows a popular but destructive SUV rodeo in Saudi Arabia (tropical desert). Center photo shows saguaro cactus in the United States (temperate desert). Bottom photo shows a Bactrian camel in Mongolia’s Gobi (cold) desert. Month Fig. 5-12b, p. 109

Polar Desert Month Mean monthly precipitation (mm) Freezing point Mean monthly precipitation (mm) Mean monthly temperature (°C) Figure 5.12 Natural capital: climate graphs showing typical variations in annual temperature (red) and precipitation (blue) in tropical, temperate, and cold deserts. Top photo shows a popular but destructive SUV rodeo in Saudi Arabia (tropical desert). Center photo shows saguaro cactus in the United States (temperate desert). Bottom photo shows a Bactrian camel in Mongolia’s Gobi (cold) desert. Month 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

Primary to secondary consumer Secondary to higher-level consumer Red-tailed hawk Gambel's Quail Yucca Agave Jack rabbit Collared lizard Prickly pear cactus Roadrunner Darkling Beetle Figure 5.13 Natural capital: some components and interactions in a temperate desert ecosystem. When these organisms die, decomposers break down their organic matter into minerals that plants use. Colored arrows indicate transfers of matter and energy between producers, primary consumers (herbivores), secondary or higher-level consumers (carnivores), and decomposers. Organisms are not drawn to scale. Bacteria Diamondback rattlesnake Fungi Kangaroo rat Producer to primary consumer Primary to secondary consumer Secondary to higher-level consumer All producers and consumers to decomposers Fig. 5-13, p. 110

GRASSLANDS AND CHAPARRAL BIOMES Variations in annual temperature (red) and precipitation (blue). Figure 5-14

Tropical grassland (savanna) Freezing point Mean monthly temperature (C) Mean monthly precipitation (mm) Figure 5.14 Natural capital: climate graphs showing typical variations in annual temperature (red) and precipitation (blue) in tropical, temperate, and polar (arctic tundra) grasslands. Top photo shows wildebeests grazing on a savanna in Maasai Mara National Park in Kenya, Africa (tropical grassland). Center photo shows wildflowers in bloom on a prairie near East Glacier Park in the U.S. state of Montana (temperate grassland). Bottom photo shows arctic tundra with caribou in Alaska’s Arctic National Wildlife Refuge (polar grassland). Month Fig. 5-14a, p. 112

Temperate grassland Month Mean monthly temperature (C) Freezing point Mean monthly temperature (C) Mean monthly precipitation (mm) Figure 5.14 Natural capital: climate graphs showing typical variations in annual temperature (red) and precipitation (blue) in tropical, temperate, and polar (arctic tundra) grasslands. Top photo shows wildebeests grazing on a savanna in Maasai Mara National Park in Kenya, Africa (tropical grassland). Center photo shows wildflowers in bloom on a prairie near East Glacier Park in the U.S. state of Montana (temperate grassland). Bottom photo shows arctic tundra with caribou in Alaska’s Arctic National Wildlife Refuge (polar grassland). Month Fig. 5-14b, p. 112

Polar grassland (arctic tundra) Freezing point Mean monthly temperature (C) Mean monthly precipitation (mm) Figure 5.14 Natural capital: climate graphs showing typical variations in annual temperature (red) and precipitation (blue) in tropical, temperate, and polar (arctic tundra) grasslands. Top photo shows wildebeests grazing on a savanna in Maasai Mara National Park in Kenya, Africa (tropical grassland). Center photo shows wildflowers in bloom on a prairie near East Glacier Park in the U.S. state of Montana (temperate grassland). Bottom photo shows arctic tundra with caribou in Alaska’s Arctic National Wildlife Refuge (polar grassland). Month Fig. 5-14c, p. 112

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.

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 Temperate tall-grass prairie ecosystem in North America. Figure 5-16

Golden eagle Pronghorn antelope Coyote Grasshopper sparrow Grasshopper Blue stem grass Prairie dog Figure 5.15 Natural capital: some components and interactions in a temperate tall-grass prairie ecosystem in North America. When these organisms die, decomposers break down their organic matter into minerals that plants can use. Colored arrows indicate transfers of matter and energy between producers, primary consumers (herbivores), secondary or higher level consumers (carnivores), and decomposers. Organisms are not drawn to scale. 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

Polar Grasslands Polar grasslands are covered with ice and snow except during a brief summer. Figure 5-17

Long-tailed jaeger Grizzly bear Caribou Mosquito Snowy owl Arctic fox Horned lark Willow ptarmigan Dwarf Willow Figure 5.17 Natural capital: some components and interactions in an arctic tundra (polar grassland) ecosystem. When these organisms die, decomposers break down their organic matter into minerals that plants use. Colored arrows indicate transfers of matter and energy between producers, primary consumers (herbivores), secondary or higher-level consumers (carnivores), and decomposers. Organisms are not drawn to scale. 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

Chaparral Chaparral has a moderate climate but its dense thickets of spiny shrubs are subject to periodic fires. Figure 5-18

FOREST BIOMES Variations in annual temperature (red) and precipitation (blue) in tropical, temperate, and polar forests. Figure 5-19

Tropical rain forest Month Mean monthly temperature (C) Freezing point Mean monthly temperature (C) Mean monthly precipitation (mm) Figure 5.19 Natural capital: climate graphs showing typical variations in annual temperature (red) and precipitation (blue) in tropical, temperate, and polar (cold) forests. Top photo shows the closed canopy of a tropical rain forest in the western Congo Basin of Gabon, Africa. Middle photo shows a temperate deciduous forest in the U.S. state of Rhode Island during the fall. Photo 9 in the Detailed Contents shows this same area of forest during winter. Bottom photo shows a northern coniferous forest in the Malheur National Forest and Strawberry Mountain Wilderness in the U.S. state of Oregon. Month Fig. 5-19a, p. 116

Temperate deciduous forest Freezing point Mean monthly temperature (C) Mean monthly precipitation (mm) Figure 5.19 Natural capital: climate graphs showing typical variations in annual temperature (red) and precipitation (blue) in tropical, temperate, and polar (cold) forests. Top photo shows the closed canopy of a tropical rain forest in the western Congo Basin of Gabon, Africa. Middle photo shows a temperate deciduous forest in the U.S. state of Rhode Island during the fall. Photo 9 in the Detailed Contents shows this same area of forest during winter. Bottom photo shows a northern coniferous forest in the Malheur National Forest and Strawberry Mountain Wilderness in the U.S. state of Oregon. Month Fig. 5-19b, p. 116

Polar evergreen coniferous forest (boreal forest, taiga) Freezing point Mean monthly temperature (C) Mean monthly precipitation (mm) Figure 5.19 Natural capital: climate graphs showing typical variations in annual temperature (red) and precipitation (blue) in tropical, temperate, and polar (cold) forests. Top photo shows the closed canopy of a tropical rain forest in the western Congo Basin of Gabon, Africa. Middle photo shows a temperate deciduous forest in the U.S. state of Rhode Island during the fall. Photo 9 in the Detailed Contents shows this same area of forest during winter. Bottom photo shows a northern coniferous forest in the Malheur National Forest and Strawberry Mountain Wilderness in the U.S. state of Oregon. Month 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 Squirrel monkeys Climbing monstera palm Katydid Slaty-tailed trogon Green tree snake Tree frog Figure 5.20 Natural capital: some components and interactions in a tropical rain forest ecosystem. When these organisms die, decomposers break down their organic matter into minerals that plants use. Colored arrows indicate transfers of matter and energy between producers, primary consumers (herbivores), secondary or higher-level consumers (carnivores), and decomposers. Organisms are not drawn to scale. 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 Height (meters) Understory Woolly opossum Figure 5.21 Natural capital: stratification of specialized plant and animal niches in a tropical rain forest. Filling such specialized niches enables species to avoid or minimize competition for resources and results in the coexistence of a great variety of species. Shrub layer Brazilian tapir Ground layer Black-crowned antipitta Fig. 5-21, p. 118

Temperate Deciduous Forest Most of the trees survive winter by dropping their leaves, which decay and produce a nutrient-rich soil. Figure 5-22

Primary to secondary consumer Secondary to higher-level consumer Broad-winged hawk Hairy Woodpecker Gray Squirrel White oak White-footed mouse Metallic wood-boring beetle and Larvae White-tailed deer Mountain Winterberry Shagbark hickory Figure 5.22 Natural capital: some components and interactions in a temperate deciduous forest ecosystem. When these organisms die, decomposers break down their organic matter into minerals that plants use. Colored arrows indicate transfers of matter and energy between producers, primary consumers (herbivores), secondary or higher-level consumers (carnivores), and decomposers. Organisms are not drawn to scale. May beetle Racer Long-tailed weasel Fungi Bacteria Wood frog Producer to primary consumer 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

Primary to secondary consumer Secondary to higher-level consumer Blue jay Great horned owl Marten Balsam fir Moose White Spruce Wolf Bebb willow Pine sawyer beetle and larvae Snowshoe hare Figure 5.23 Natural capital: some components and interactions in an evergreen coniferous (boreal or taiga) forest ecosystem. When these organisms die, decomposers break down their organic matter into minerals that plants use. Colored arrows indicate transfers of matter and energy between producers, primary consumers (herbivores), secondary or higher-level consumers (carnivores), and decomposers. Organisms are not drawn to scale. Fungi Starflower Bunchberry Bacteria Producer to primary consumer Primary to secondary consumer Secondary to higher-level consumer 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

MOUNTAIN BIOMES High-elevation islands of biodiversity Often have snow-covered peaks that reflect solar radiation and gradually release water to lower-elevation 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.

Natural Capital Degradation Desert Large desert cities Soil destruction by off-road vehicles Soil salinization from irrigation Figure 5.26 Natural capital degradation: major human impacts on the world’s deserts. QUESTION: What are three direct and three indirect harmful effects of your lifestyle on deserts? 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 Figure 5.27 Natural capital degradation: major human impacts on the world’s grasslands. Some 70% of Brazil’s tropical savanna—once the size of the Amazon—has been cleared and converted to the world’s biggest grain growing area. QUESTION: What are three direct and three indirect harmful effects of your lifestyle on grasslands? 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 Figure 5.28 Natural capital degradation: major human impacts on the world’s forests. QUESTION: What are three direct and three indirect effects of your lifestyle on forests? 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 Figure 5.29 Natural capital degradation: major human impacts on the world’s mountains. QUESTION: What are three direct and three indirect harmful effects of your lifestyle on mountains? Increased ultraviolet radiation from ozone depletion Soil damage from off-road vehicles Fig. 5-29, p. 124