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Local Conditions

How would you describe your climate, or the average, year-after-year conditions of temperature and precipitation where you live? Does your area receive a great deal of precipitation—rain and snow—or is your area very dry?

Section 4-1

Interest Grabber

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1. When does the area in which you live experience the lowest temperatures? Does the temperature ever get below freezing? If so, how often does this occur?

2. When does the area in which you live have the highest temperatures? About how high is the highest temperature?

3. How often does it rain where you live? Is one season rainier than the others?

4. Does it ever snow where you live? If so, what is the heaviest snowfall you can remember?

5. What are two factors that may affect climate?

Section 4-1

Interest Grabber continued

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4–1 The Role of Climate A. What Is Climate? B. The Greenhouse Effect C. The Effect of Latitude on Climate D. Heat Transport in the Biosphere

Section 4-1

Section Outline

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What is Climate?

• Weather is the day-to-day condition of Earth’s atmosphere at a particular time and place.

• Climate is the year-after-year conditions of temperature and precipitation in a particular region.

• Climate is caused by the interplay of several factors such as the trapping of heat by the atmosphere, the latitude, the transport of heat by winds and ocean currents, and the amount of precipitation that results. • Energy from incoming sunlight drives Earth’s weather and helps determine climate.

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Greenhouse Effect • Temperature on Earth remains in a range suitable for life because it has a natural insulating blanket - the atmosphere. • Carbon dioxide, methane, water vapor, and a few other atmospheric gases trap heat energy and maintain Earth’s temperature range. • The natural situation in which heat is retained by this layer of greenhouse gases is called the Greenhouse Effect.

Some heat escapes into space

Earth’s surface

Greenhouse gases trap some heat

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The Effects of Latitude on Climate

• Because Earth’s axis is on a tilt, the rays of light from the sun hit Earth at different angles. • As a result of differences in latitude and thus the angle of heating, Earth has three main climate zones, polar, temperate, and tropical. • The polar zones are extremely cold and are located around the North and South Pole, 66.5° and 90°. • The temperate zone is in the middle of the Earth, 23.5° - 66.5°. As a result, it has 4 seasons. • The tropical zone is located near the equator, 0° - 23.5°. It receives almost direct sunlight. As a result, it is usually always warm.

Sunlight

Most direct sunlight

Sunlight

Sunlight

Sunlight

90°N North Pole

66.5°N

23.5°N

0°

23.5°S

66.5°S 90°S South Pole

Arctic circle

Tropic of Cancer

Equator

Tropic of Capricorn

Arctic circle

Different Latitudes

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Heat Transport in the Biosphere

• The unequal heating of Earth’s surface drives winds and ocean currents, which transports heat throughout the biosphere. • Winds form because warm air rises and cool air sinks. • The same thing happens with ocean water. The cold water near the poles sinks and runs parallel to the ocean’s bottom, eventually rising near the equator through a process called upwelling. The surface water is moved by the winds.

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Sunlight

Some heat escapes into space

Greenhouse gases trap some heat

Atmosphere

Earth’s surface

Section 4-1

The Greenhouse Effect

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Sunlight

Some heat escapes into space

Greenhouse gases trap some heat

Atmosphere

Earth’s surface

Sunlight

Most direct sunlight

Sunlight

Sunlight

Sunlight

90°N North Pole

66.5°N

23.5°N

0°

23.5°S

66.5°S 90°S South Pole

Arctic circle

Tropic of Cancer

Equator

Tropic of Capricorn

Arctic circle

Section 4-1

Figures 4-1 and 4-2 Heating of the Earth’s Surface and Some Factors That Affect Climate

Greenhouse Effect Different Latitudes

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Fitting In

Organisms not only live together in ecological communities, but they also constantly interact with one another. These interactions, which include predation and competition, help shape the ecosystem in which they live.

1. Based on your own experiences, define predation. Give one example of predation.

2. Based on your own experiences, define competition. Give one example of competition.

Section 4-2

Interest Grabber

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4–2 What Shapes an Ecosystem? A. Biotic and Abiotic Factors B. The Niche C. Community Interactions

1. Competition 2. Predation 3. Symbiosis

D. Ecological Succession 1. Primary Succession 2. Secondary Succession 3. Succession in a Marine Ecosystem

Section 4-2

Section Outline

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Biotic and Abiotic Factors • Biotic factors - Biological influences on organisms within an ecosystem.

–  Any living thing; trees, grass, birds, deer, etc. • Abiotic factors - Physical, or nonliving, factors that shape ecosystems.

–  Nonliving things, rocks, water, air, wind, climate, etc.

• Together, biotic and abiotic factors determine the survival and growth of an organism and the productivity of the ecosystem in which the organism lives. • The area where an organism lives is called its habitat.

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Biotic Factors

ECOSYSTEM

Abiotic Factors

Section 4-2

Abiotic and Biotic Factors

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Biotic Factors

ECOSYSTEM

Abiotic Factors

Section 4-2

Abiotic and Biotic Factors

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The Niche

• A niche is the full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions. • In other words, a niche is an organism’s job in the ecosystem. • A niche can include its place in a food web, temperatures needed for survival, typed of food it eats, how it gets its food, and how and when it reproduces.

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Bay-Breasted Warbler Feeds in the middle part of the tree

Yellow-Rumped Warbler Feeds in the lower part of the tree and at the bases of the middle branches

Cape May Warbler Feeds at the tips of branches near the top of the tree

Spruce tree

Section 4-2

Figure 4-5 Three Species of Warblers and Their Niches

No two organisms can occupy the same niche in the same place at the same time.

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Community Interactions

• Community interactions, such as competition, predation, and various forms of symbiosis, can powerfully affect an ecosystem.

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Competition • Competition occurs when organisms of the same or different species attempt to use an ecological resource in the same place at the same time. • A resource is any necessity of life, such as water, food, space. • Direct competition in nature leads to a winner and a loser, who may not survive. • Competitive exclusion principle states that no two species can occupy the same niche in the same habitat at the same time.

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Predation

• A predator is an organism that captures and feeds on another organism. • The organism that is eaten is called the prey.

Symbiosis • Any relationship in which two species live closely together. • There are three types of symbiosis:

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Mutualism

• Both organisms benefit from the relationship.

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Commensalism

• One member of the association benefits and the other is neither helped nor harmed.

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Parasitism

• One organism lives on or inside another organism and harms it. • The organism that is harmed is called the host. • A parasite weakens but does not kill the host and is usually smaller.

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Ecological Succession

• Ecosystems are constantly changing in response to natural and human disturbances. As an ecosystem changes, older inhabitants gradually die out and new organisms move in, causing further changes in the community. • The series of predictable changes that occur in a community over time is called ecological succession. • These changes can be slow or sudden.

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Primary Succession

• Occurs on surfaces where no soil exists. • Example: After a volcanic eruption or bear rock caused by a glacier. • The first species to occupy the area are called pioneer species. • The pioneer species of a volcanic eruption would be lichens (Fungus and alga).

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Secondary Succession

• Ecosystems can be changed by fires or human activities. • When the disturbance is over, community interactions tend to restore the ecosystem to its original condition. • This process is called Secondary Succession.

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Who’s There?

If you have ever been to a zoo or a botanical garden, you may have noticed that the signs that identify the animals or plants also identify the part of the world where these organisms are found. Different kinds of animals and plants are found in different parts of the world.

Section 4-3

Interest Grabber

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1. Describe the climate where you live.

2. What types of plant and animal life are found in your area? Describe a few of the major characteristics of these organisms.

3. Suppose that you had to move to an area with a climate that was very different from the climate you now live in. How would the plant and animal life in this new area be different from the plant and animal life where you live now?

Section 4-3

Interest Grabber continued

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4–3 Biomes A. Biomes and Climate B. The Major Biomes C. Other Land Areas

1. Mountain Ranges 2. Polar Ice Caps

Section 4-3

Section Outline

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Tropical rain forest Tropical dry forest Tropical savanna Temperate woodland

and shrubland Desert Temperate grassland

Boreal forest (Taiga)

Northwestern coniferous forest Temperate forest

Mountains and ice caps Tundra

Section 4-3

Figure 4-11 The World’s Major Land Biomes

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Tropical Rain Forest

• Facts - Largest # of different species than all other biomes combined; Canopy; Understory. • Abiotic Factors - Hot and wet; thin, nutrient-poor soil. • Dominant Plants - Broad-leafy evergreens; ferns; large, woody vines; orchids. • Dominant Wildlife - Sloths; Jaguars; Monkeys; Toucans; Anacondas. • Geographic Distribution - South and Central South America; Southeast Asia; Parts of Africa; Southern India; Northeast Australia.

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Tropical Dry Forest • Facts - Found where rainfall is seasonal; Trees drop leaves during dry season; Deciduous trees. • Abiotic Factors - Warm year-round; Wet and dry seasons; Rich soil. • Dominant Plants - Deciduous Trees; orchids; Bromeliads; Aloes and other succulents. • Dominant Wildlife - Tigers; Monkeys; Elephants; Rhinoceroses; Termites; Monitor Lizards. • Geographic Distribution - Africa; South and Central America; Mexico; India; Australia; Tropical Islands.

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Tropical Savanna • Facts - Receives more rain than deserts but less than TDF; Spotted with isolated trees; Compact soil; Frequent fires. • Abiotic Factors - Warm temperature; seasonal rainfall; compact soil; fires from lightning. • Dominant Plants - tall, perennial grasses; drought-tolerant and fire-resistant trees and shrubs. • Dominant Wildlife - Lions; Leopards; Cheetahs; Hyenas; Aardvarks; Giraffes; • Geographic Distribution - Eastern Africa; Southern Brazil; Northern Austrailia.

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Desert • Facts - < 25 cm of H2O; Undergo extreme temperature changes; Organisms tolerate extreme conditions. • Abiotic Factors - Low H2O; Variable temps; soils rich in minerals but low in organic matter. • Dominant Plants - Cacti; Creosote bush and other plants with short growth cycles. • Dominant Wildlife - Mountain lions; Gray foxes; Bobcats; Mule deer; Antelopes; Kangaroos. • Geographic Distribution - Africa, Asia, Middle East, US, Mexico, South America.

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Temperate Grasslands • Facts - Grasses, rich soil, Converted into farms. • Abiotic Factors - Warm summers, Cold winters, moderate precipitation, fertile soil. • Dominant Plants - Perennial grasses and herbs; resistant to drought, fire, and cold. • Dominant Wildlife - Coyotes; Mule deer; Rabbits; Prairie dogs; Hawks; Owls; snakes. • Geographic Distribution - Central Asia; North America; Australia; Central Europe.

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Temperate Woodland and Shrubland • Facts - Semiarid climate; Chaparral; Low plants that contain flammable oils make fires a constant threat. • Abiotic Factors - hot, dry summers; cool, moist winters; thin, nutrient-poor soils. • Dominant Plants - Woody evergreen shrubs; fragrant, oily herbs. • Dominant Wildlife - Coyotes, Foxes, mountain lions, Blacktailed deer, rabbits, squirrels. • Geographic Distribution - Western coasts of North and South America; Around Mediterranean Sea, South Africa, and Australia.

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Temperate Forest • Facts - Mixture of deciduous and coniferous trees; cold winters; soil rich in humus. • Abiotic Factors - cold winters, warm summers, year round H2O, fertile soils. • Dominant Plants - Deciduous trees, some conifers, flowering shrubs, mosses and ferns. • Dominant Wildlife - deer; black bears; bobcats; squirrels; raccoons; skunks, turkeys. • Geographic Distribution - Eastern US, SE Canada, Europe, parts of Japan, China, and Australia.

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Northwest Coniferous Forest

• Facts - Mild moist air form PO provides abundant rainfall; Mix of Conifers; “Temperate Rain Forest.” • Abiotic Factors - Mild temperatures; abundant precipitation; cool, dry summers; rocky, acidic soil. • Dominant Plants - Douglas fir, Sitka spruce, western hemlock, redwood. • Dominant Wildlife - Bears; elk; deer; beavers; owls; bobcats. • Geographic Distribution - Pacific coast on NW US and Canada.

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Boreal Forest

• Facts - AKA the Taiga; bitterly cold winters; mild summers; Means “north.” • Abiotic Factors - long, cold winters; short, mild summers; moderate precipitation; acidic, nutrient-poor soil. • Dominant Plants - Coniferous trees; some deciduous trees; small, berry-bearing shrubs. • Dominant Wildlife - Lynxes, timber wolves, moose, beavers, migratory birds. • Geographic Distribution - North America, Asia, Northern Europe.

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Tundra • Facts - Characterized by the permafrost; short cool summers that thaw only a few cm deep; plants are small and stunted. Humus-poor soil. • Abiotic Factors - Strong winds; low precipitation; short summers; long, cold and dark winters; permafrost. • Dominant Plants - mosses, lichens, sedges, and short grasses. • Dominant Wildlife - Migratory waterfowl, musk ox, arctic foxes, caribou. • Geographic Distribution - Northern North America, Asia, and Europe.

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Other Land Areas

• Mountain Ranges: Biotic and Abiotic conditions change with elevation. • As elevation increases, the temperature gets colder and precipitation increases.

• Polar Ice Caps: They are cold year round. In the north, dominant plants include mosses and lichens. Animals include polar bears, seals, insects, and mites. • In the south, Antarctica is covered by a layer of ice 5 km thick. Wildlife includes penguins and marine mammals.

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Section 4-3

Compare/Contrast Table

Ten Major Biomes Biome Precipitation Temperature Soil Diversity Trees Grasses Tropical Rain Forest high hot poor high dense sparse

Tropical Dry Forest variable mild rich moderate medium medium

Tropical Savanna variable mild clay moderate sparse dense Desert low variable poor moderate sparse sparse Temperate Grassland moderate summer hot rich moderate absent dense

Temperate woodland and Shrubland

summer low, winter moderate

summer hot poor low medium medium

Temperate Forest moderate summer moderate, winter cold

rich high dense sparse

Northwestern Coniferous Forest

high summer mild, winter cold

rocky, acidic low dense sparse

Boreal Forest moderate summer mild, winter cool

poor, acidic moderate dense sparse

Tundra low summer mild, winter cold

poor low absent medium

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Ride the Waves

The marine ecosystem that is exposed to regular and extreme changes in its surroundings is the intertidal zone. During high tide, the intertidal zone is covered by sea water. During low tide, this area is exposed to air, sunlight, and heat.

Section 4-4

Interest Grabber

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1. What types of organisms would you expect to find living in the intertidal zone?

2. What characteristics do you think these organisms have that enable them to live in this zone?

3. What effect do waves have on the intertidal zone?

Interest Grabber continued

Section 4-4

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4–4 Aquatic Ecosystems A. Freshwater Ecosystems

1. Flowing-Water Ecosystems 2. Standing-Water Ecosystems 3. Freshwater Wetlands

B. Estuaries C. Marine Ecosystems

1. Intertidal Zone 2. Coastal Ocean 3. Coral Reefs 4. Open Ocean 5. Benthic Zone

Section 4-4

Section Outline

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Freshwater Ecosystems • Flowing-water Ecosystems

–  Rivers, Streams, Creeks, and Brooks –  Organisms are well adapted for the conditions (hooks, suckers, and

stream-lined bodies) • Standing-water Ecosystems

–  Lakes and Ponds –  Habitat for Phytoplankton and Zooplankton

• Fresh-Water Wetlands –  Can be flowing, standing, fresh water, salt water or brackish. –  Bogs - Formed in depressions. Dominated by sphagnum moss. –  Marshes - found along rivers. Contain cattails, rushes, and grass-

like plants. –  Swamps - Wet year round. Contain trees and shrubs. Flooded all

year.

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Spoonbill

Duck

Dragonfly Phytoplankton

Frog Water lilies Mosquito

larvae

Snail Diving beetle

Trout

Pickerel

Duckweed

Snail Benthic crustaceans

Hydra

Frogs lay eggs in the shallow water near shore.The eggs hatch in the water as tadpoles and move to the land as adults.

The shore is lined with grasses that provide shelter and nesting places for birds and other organisms.

The roots of water lilies cling to the pond bottom, while their leaves, on long flexible stems, float on the surface.

The bottom of the pond is inhabited by decomposers and other organisms that feed on particles drifting down from the surface.

Fish share the pond with turtles and other animals. Many of them feed on insects at the water’s edge.

Plankton and the organisms that feed on them live near the surface where there is enough sunlight for photosynthesis. Microscopic algae are among the most important producers.

Section 4-4

Freshwater Pond Ecosystem

Crayfish

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Estuaries

• Wetlands formed where rivers meet the sea. • Primary producers are plants, algae, and bacteria. • Support an astonishing amount of biomass. • Breeding-grounds for many types of fish and shellfish. • Salt Marshes - Estuary dominated by salt-tolerant grasses along the East Coast from Maine to Georgia.

–  Largest system is the Chesapeake Bay Estuary. • Mangrove Swamps - Coastal wetlands in the tropical region of the US that are dominated by salt-tolerant trees and grasses.

–  Largest system is the Florida everglades.

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Salt Marsh Mangrove Swamp

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Marine Ecosystem

• Photic Zone vs. Aphotic Zone • Four other zones:

–  Intertidal zone –  Coastal zone –  Open ocean –  Benthic Zone

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land Coastal ocean

Open ocean

Ocean trench

Aphotic zone

Photic zone

Continental shelf

Continental slope and continental rise

Abyssal plain

200m 1000m

4000m

6000m

10,000m

Section 4-4

Figure 4-17 Zones of a Marine Ecosystem

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Intertidal Zone

•  Organisms are exposed to different environments twice a day.

•  They are either covered with ocean water (high tide) or exposed to sunlight, temperature, and the wind.

•  Organisms include barnacles, seaweed, snails, sea urchins, and sea stars.

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Coastal Ocean

•  Extends from the low tide mark all the way to the end of the continental shelf.

•  Usually falls in the photic zone, so, photosynthesis can take place.

•  Rich in plankton and kelp. •  Other organisms include

snails, sea urchins, sea otters, fish, and whales.

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Coral Reef

•  In the warm coastal regions, coral reefs are among the most diverse and productive environments on Earth.

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Open Ocean

•  Starts at the end of the continental shelf and continues outward.

•  It is the largest ocean zone covering 90% of the surface area of the Earth’s oceans.

•  Depth ranges from 500 m to more than 11,000 m.

•  Organisms include plankton, swordfish, octopus, whales, and dolphins.

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Benthic Zone

•  This zone includes the entire ocean floor. •  Main organisms include sea stars, anemones, and marine

worms. •  These organisms are called benthos. •  These organisms feed on the dead organic material,

detritus, that falls from the surface.

Video Contents

Videos

Click a hyperlink to choose a video. Earth’s Many Biomes, Part 1 Earth’s Many Biomes, Part 2

Video 1

Click the image to play the video segment.

Video 1

Earth’s Many Biomes, Part 1

Video 2

Click the image to play the video segment.

Video 2

Earth’s Many Biomes, Part 2

Internet

Career links on forestry technicians Interactive test

For links on climate and the greenhouse effect, go to www.SciLinks.org and enter the Web Code as follows: cbn-2041. For links on biomes, go to www.SciLinks.org and enter the Web Code as follows: cbn-2043. For links on aquatic ecosystems, go to www.SciLinks.org and enter the Web Code as follows: cbn-2044.

Go Online

Section 1 Answers

Interest Grabber Answers

1. When does the area in which you live experience the lowest temperatures? Does the temperature ever get below freezing? If so, how often does this occur?

2. When does the area in which you live have the highest temperatures? About how high is the highest temperature?

3. How often does it rain where you live? Is one season rainier than the others?

4. Does it ever snow where you live? If so, what is the heaviest snowfall you can remember?

Question 1–4:Answers will vary depending on local conditions. If students have lived in a different part of the country, you may wish to have them contrast the climate in that area with the local climate.

5. What are two factors that may affect climate? Possible answers: latitude, wind, ocean currents, shape and elevation of land masses

Section 2 Answers

Interest Grabber Answers

1. Based on your own experiences, define predation. Give one example of predation. Predation is an interaction in which one organism captures and feeds on another organism. Some examples of predation: a hawk captures and feeds on a rabbit; a cat captures and feeds on a mouse.

2. Based on your own experiences, define competition. Give one example of competition. Competition occurs when organisms of the same or different species attempt to use an ecological resource in the same place at the same time. Some examples of competition: crop plants and weeds compete for food, water, and sunlight; wolves and foxes compete for the same food (rabbits).

Section 3 Answers

Interest Grabber Answers

1. Describe the climate where you live. 2. What types of plant and animal life are found in your area? Describe a

few of the major characteristics of these organisms. Questions 1–2: Answers will vary depending on the part of the country in which students live.

3. Suppose that you had to move to an area with a climate that was very different from the climate you now live in. How would the plant and animal life in this new area be different from the plant and animal life where you live now? Sample answer: If the new climate were much colder, animals would probably have thicker fur. Plants would have shorter growing seasons and would produce seeds that could withstand the cold.

Section 4 Answers

Interest Grabber Answers

1. What types of organisms would you expect to find living in the intertidal zone? Students may say that plants and animals would be small.

2. What characteristics do you think these organisms have that enable them to live in this zone? Possible answer: Plants would have thick outer layers to resist drying during low tide. Animals would be able to burrow into the sand or have coverings that could hold in water.

3. What effect do waves have on the intertidal zone? Waves pound living things, causing them to bounce around, unless they have some means of staying attached to the sand or rocks on the bottom.

End of Custom Shows

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